Infrastructure Engine of India’s Development Class 7 Worksheet with Answers SST Chapter 7

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Infrastructure Engine of India’s Development Worksheet Class 7

Class 7 Infrastructure Engine of India’s Development Worksheet

Worksheet On Infrastructure Engine of India’s Development Class 7 – Infrastructure Engine of India’s Development Worksheet

Multiple Choice Questions (MCQs)

Question 1.
Which of the following is an example of an energy infrastructure project in India?
(a) Coal mines
(b) Muppandal wind farm
(c) National highways
(d) Oil storage depots
Answer:
(b) Muppandal wind farm

Question 2.
What is the main function of bridges and tunnels in India?
(a) Provide tourist attractions
(b) Reduce energy consumption
(c) Enable connectivity in difficult terrains
(d) Generate electricity
Answer:
(c) Enable connectivity in difficult terrains

Question 3.
Which state has implemented the Solar Power Project at Cochin International Airport?
(a) Tamil Nadu
(b) Kerala
(c) Maharashtra
(d) Karnataka
Answer:
(b) Kerala

Question 4.
Living root bridges of Meghalaya are an example of
(a) Modern engineering
(b) Indigenous ecological knowledge
(c) Steel bridge technology
(d) Temporary structures
Answer:
(b) Indigenous ecological knowledge

Question 5.
Which of the following statements about Indian Railways is true?
(a) It uses more energy than road transport
(b) It employs over one million people
(c) It only carries cargo
(d) It started in 1901
Answer:
(b) It employs over one million people

Question 6.
Which feature of metro trains helps reduce city pollution?
(a) Slower travel speed
(b) Use of clean energy
(c) More private vehicles
(d) Coal-based locomotives
Answer:
(b) Use of clean energy

Question 7.
The Golden Quadrilateral is a network of highways that connects
(a) Northern and Southern states only
(b) Major port cities of India
(c) India’s four major metropolitan cities
(d) Capital cities of neighbouring countries
Answer:
(c) India’s four major metropolitan cities

Question 8.
Air transport is particularly useful for delivering
(a) Bulk coal
(b) Perishable goods like vaccines
(c) Cement
(d) Cars
Answer:
(b) Perishable goods like vaccines

Question 9.
Which of the following is not included in communication infrastructure?
(a) Towers
(b) Data centres
(c) Roads
(d) Satellites
Answer:
(c) Roads

Question 10.
The Dhola Sadiya Bridge reduced travel time by approximately
(a) 2 hours
(b) 3 hours
(c) 4 hours
(d) 5 hours
Answer:
(c) 4 hours

Question 11.
Which Indian institute was founded by Jagadish Chandra Bose?
(a) IIT Delhi
(b) Bose Institute
(c) IISc Bangalore
(d) ISRO
Answer:
(b) Bose Institute

Assertion-Reason

Given below are two statements marked as Assertion (A) and Reason (R). Read the statements and answer the questions according to the codes given below.
Codes
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true, but R is not the correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true

1. Assertion (A) Bridges and tunnels improve connectivity in hilly regions.
Reason (R) Highways cannot be easily built in dense forests or steep mountains.
Answer:
(a) Both A and R are true and R is the correct explanation of A

2. Assertion (A) Metro trains help reduce air pollutio l in cities.
Reason (R) They reduce the number of private vehicles on the roads.
Answer:
(a) Both A and R are true and R is the correct explanation of A

3. Assertion (A) Air transport is crucial during natural disasters.
Reason (R) Aircraft can reach difficult terrains quickly.
Answer:
(a) Both A and R are true and R is the correct explanation of A

4. Assertion (A) Shipping is an important mode of transport for heavy goods.
Reason (R) India’s ports connect domestic and international markets efficiently.
Answer:
(b) Both A and R are true, but R is not the correct explanation of A

5. Assertion (A) Communication infrastructure enables e-govemance.
Reason (R) Digital systems allow citizens to apply for documents and services online.
Answer:
(a) Both A and R are true and R is the correct explanation of A

Fill in the Blanks

Fill in the blanks with the help of words given in the box below.
Arunachal Pradesh, Central, 7516, Semi-high-speed, 23,16, Garden city, Telegraph
1. The Dhola Sadiya Bridge connects Assam and ________.
Answer:
Arunachal Pradesh

2. National highways are primarily built and maintained by the ________ government.
Answer:
Central

3. India has a coastline of approximately ________ km.
Answer:
7516

4. The Vande Bharat Express is a modern ________train.
Answer:
Semi-high-speed

5. Metro trains operate in over ________ cities across India.
Answer:
23

6. Kautilya recommended that royal highways should be ________ metres wide.
Answer:
16

7. Airports that combine green spaces with modern infrastructure follow the ________ concept.
Answer:
Garden city

8. Before mobile phones, people sent long-distance messages using ________.
Answer:
Telegraph

Write ‘T’ for True or ‘F’ for False statements.

1. Indian Railways is the fourth-largest railway system in the world.
Answer:
True

2. The Bhakra Nangal Dam is a multipurpose dam in Himachal Pradesh.
Answer:
True

3. Living root bridges are made using bamboo trunks only.
Answer:
False

4. Rail transport consumes 75-90% less energy than road transport.
Answer:
True

5. The first newspaper in India was printed in 1780.
Answer:
True

6. Solar energy projects are part of India’s physical infrastructure.
Answer:
True

7. Metro trains only operate on underground tracks.
Answer:
False

8. Kautilya emphasised both government and citizen responsibility for infrastructure.
Answer:
True

Match the Columns

Question 1.
Match the bridges in Column A with their states in Column B.

Column A (Bridge)	Column B (State)
A. Dhola Sadiya Bridge	1. West Bengal
B. Howrah Bridge	2. Assam-Arunachal Pradesh
C. Bandra-Worli Sea Link	3. Maharashtra
D. Chenab Rail Bridge	4. Jammu & Kashmir

Answer:

Column A (Bridge)	Column B (State)
A. Dhola Sadiya Bridge	2. Assam-Arunachal Pradesh
B. Howrah Bridge	1. West Bengal
C. Bandra-Worli Sea Link	3. Maharashtra
D. Chenab Rail Bridge	4. Jammu & Kashmir

Question 2.
Match the transport modes in Column A with their features in Column B.

Column A	Column B
A. Metro Train	1. Built and maintained by the central government
B. Vande Bharat Express	2. Modem semi-high-speed train
C. National Highway	3. Operates in urban cities with high frequency
D. Air Transport	4. Useful in emergencies and long-distance travel

Answer:

Column A	Column B
A. Metro Train	3. Operates in urban cities with high frequency
B. Vande Bharat Express	2. Modem semi-high-speed train
C. National Highway	1. Built and maintained by the central government
D. Air Transport	4. Useful in emergencies and long-distance travel

Jumbled Words

Rearrange the alphabets to form a correct word.
1. DLOHA SAYIDA
Hint: Longest bridge in Assam connecting to Arunachal Pradesh
Answer:
OHOLA SADIYA

2. VDAEN RAT AH B
Hint: Modem electric train
Answer:
VANDE BHARAT

3. FCSUI TECALISA RTOOS
Hint: Type of living bridge in Meghalaya.
Answer:
FICUS ELASTICA ROOTS

4. KOEMGPEDWA AIRPTOR Hint An airport in Karnataka.
Answer:
KEMPEGOWDA AIRPORT

Very Short Answer Type Questions

Question 1.
What type of infrastructure includes roads and bridges?

Question 2.
Which expressway connects Delhi and Meerut?

Question 3.
Which state is Visakhapatnam Port located in?

Question 4.
Name one indirect job created by railways.

Question 5.
Which airport follows the ‘garden city’ concept?

Question 6.
Which mode of transport is cheapest for heavy goods?

Question 7.
How many minor ports does India have?

Question 8.
Which body is responsible for local infrastructure maintenance?

Question 9.
What type of infrastructure damage burdens citizens?

Question 10.
Which transport helps during floods and earthquakes?

Short Answer Type Questions

Question 1.
Why is physical infrastructure called the backbone of a nation?

Question 2.
How do roads and highways support daily life in villages and cities?

Question 3.
What is communication infrastructure? Mention any two of its components.

Question 4.
Why is maintaining public infrastructure a collective responsibility?

Long Answer Type Questions

Question 1.
During a visit to an industrial city, you observe airplanes transporting goods and people efficiently. Explain how air transport contributes to economic development and also assists during emergency situations.

Question 2.
While exploring history and modern technology, you learn about methods of communication from old to new. Trace the development of communication systems in India, starting from ancient methods to modem digital technology.

Question 3.
In your neighbourhood, you see well-maintained roads, parks and water pipelines. Discuss ways in which citizens can contribute to maintaining public infrastructure and explain how collective responsibility enhances community wellbeing.

Source Based Question

Read the source given below and answer the following questions.
Technology has changed the way we communicate, making it faster and easier through devices like phones, computers, and tablets. Behind this is a communication infrastructure, including cables, towers, satellites, and data centres, that helps messages, images and videos travel across long distances. When Rani, from a village in Madhya Pradesh, sends a voice note to her cousin in Tamil Nadu, it seems simple just tap, record, send. But the message travels through towers, fibre cables, satellites and big servers before reaching her cousin.
(i) Why does it feel easy for Rani to send a message even though it travels a long way?
(ii) How do you think villages and cities are connected through this communication system?
(iii) What do you think would happen if the towers or servers stopped working?

Picture Based Questions

Question 1.
Observe the picture given below and answer the following questions.

(i) Name the bridge shown in the picture and in which Indian state is this bridge located?
(ii) Why is this bridge considered significant in India’s railway infrastructure?

Question 2.
Observe the picture given below and answer the following questions.

(i) Which airport is shown in the picture?
(ii) What type of renewable energy project is visible in the picture?

Activity

Question 1.
Instruction Find and circle the hidden words related to infrastructure.

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NCERT Class 7 Social Science Worksheets with Answers Pdf

Exploring Society India and Beyond Class 7 Social Science Workbook Answers, NCERT Practice Workbook Social Science Class 7 Solutions, Exploring Society India and Beyond Class 7 SST Workbook Answers, SST Workbook Class 7 Solutions.

SST Worksheet for Class 7 with Answers

Exploring Society India and Beyond Class 7 Worksheet

Class 7 SST Worksheet with Answers – Social Science Workbook Class 7 Solutions

• Chapter 1 Geographical Diversity of India Class 7 Worksheet
• Chapter 2 Understanding the Weather Class 7 Worksheet
• Chapter 3 Climates of India Class 7 Worksheet
• Chapter 4 New Beginnings: Cities and States Class 7 Worksheet
• Chapter 5 The Rise of Empires Class 7 Worksheet
• Chapter 6 The Age of Reorganisation Class 7 Worksheet
• Chapter 7 The Gupta Era An Age of Tireless Creativity Class 7 Worksheet
• Chapter 8 How the Land Becomes Sacred Class 7 Worksheet
• Chapter 9 From the Rulers to the Ruled Types of Governments Class 7 Worksheet
• Chapter 10 The Constitution of India An Introduction Class 7 Worksheet
• Chapter 11 From Barter to Money Class 7 Worksheet
• Chapter 12 Understanding Markets Class 7 Worksheet

Exploring Society India and Beyond Class 7 Worksheet Pdf Part 2

• Chapter 1 The Story of Indian Farming Class 7 Notes
• Chapter 2 India and Her Neighbours Class 7 Notes
• Chapter 3 Empires and Kingdoms 6th to 10th Centuries Class 7 Notes
• Chapter 4 Turning Tides 11th and 12th Centuries Class 7 Notes
• Chapter 5 India A Home to Many Class 7 Notes
• Chapter 6 The State the Government and You Class 7 Notes
• Chapter 7 Infrastructure Engine of India’s Development Class 7 Notes
• Chapter 8 Banks and the Magic of Finance Class 7 Notes

Also Read

• Exploring Society India and Beyond Class 7 Solutions
• Class 7 SST Extra Questions
• Class 7 Social Science MCQ
• Class 7 Social Science Notes (SST)
• Class 7 Social Science Worksheet (SST)
• NCERT Solutions for Class 7
• NCERT Books for Class 7

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Patterns in Life Diversity and Classification Class 9 Notes Science Chapter 12

Reviewing Class 9 Science Notes and Exploration Chapter 12 Patterns in Life Diversity and Classification Class 9 Notes regularly helps in retaining important facts.

Class 9 Science Chapter 12 Patterns in Life Diversity and Classification Notes

Class 9 Science Exploration Chapter 12 Notes

Class 9 Science Chapter 12 Notes – Class 9 Patterns in Life Diversity and Classification

→ Biodiversity: It refers to the wide variety of living organisms found on Earth, from microscopic organisms to large plants and animals. It includes life in different habitats like forests, oceans, and mountains.

→ Biodiversity is essential for maintaining balance in nature. Every organism plays a role in keeping ecosystems stable and functioning properly.

→ Humans depend on biodiversity for food, shelter, medicines, and livelihoods. Farmers conserve different crop varieties to ensure better yield and survival.

→ Classification: Classification is the process of grouping organisms based on their similarities and differences, as well as their evolutionary relationships.

→ Need for Classification: Classification helps scientists understand how organisms are related, how they function, and how this knowledge can be used in conservation and sustainable practices.

→ Endemic species: Endemic species are organisms found only in a specific region. Examples: Nilgiritahr, Lion-tailed macaque, Indian variety of the pitcher plant-Nepenthes khasiczna, and Neelakurinji are found only in India.

→ Hotspots: Hotspots are regions rich in biodiversity but under threat. Examples: Western Ghats, Himalayas, North East India, Nicobar Islands.

→ Evolution: It is the gradual change in organisms leading to new species.

→ Evolution of Biodiversity: Biodiversity developed over millions of years through evolution. Small variations helped organisms survive better, and useful traits were passed to future generations, forming new species.

→ Criteria for Classification: Organisms are classified based on features like structure, nutrition, and cell type. These help in grouping organisms scientifically.

• External features: shape, size, body structure.
• Cell type: prokaryotic or eukaryotic.
• Organisation: unicellular or multicellular.
• Mode of nutrition: autotrophic or heterotrophic.
• Cell wall: presence or absence.
• Reproduction: asexual and/or sexual.
• Ecological role.
• Genetic similarity.

→ Biological Classification: It is the scientific system of grouping living organisms based on their similarities and differences in features such as external structure, internal organisation, and cellular structure.

→ Aristotle’s Classification: Around the 4th century BCE, Aristotle classified animals based on their habitat (land, water, air) and external features. This system had limitations as it relied only on visible characteristics.

→ Two-kingdom classification system: In the 18th century, scientists divided all living organisms into two kingdoms – Plantae and Animalia.

• Kingdom Plantae: Includes organisms that are non-motile (do not move) and can make their own food through photosynthesis.
• Kingdom Animalia: Includes organisms that move from place to place and depend on other organisms for food. This system created confusion for organisms like Amoeba, Paramecium and bacteria, as they did not fit clearly into either group.

→ Three-kingdom system (Protista added): To overcome the two-kingdom classification system limitation, a new kingdom Protista was introduced to include unicellular microscopic organisms such as Amoeba and Paramecium, which show both plant-like and animal-like features.

→ Four-kingdom system (Monera separated):
With the improvement of microscopes, scientists observed that bacteria do not have a true nucleus, unlike Amoeba. Therefore, bacteria were placed in a separate kingdom called Monera, leading to a four-kingdom classification system.

→ Five-kingdom classification system: This system includes Monera, Protista, Fungi, Plantae, and Aninialia, providing a more accurate way to classify living organisms.

→ Basis of Five Kingdom Classification:

• Cell type: prokaryotic or eukaryotic.
• Level of organisation: unicellular or multicellular.
• Cell structure: presence or absence of a cell wall.
• Mode of nutrition: autotrophic or heterotrophic.

→ Kingdom Monera: It includes unicellular prokaryotic organisms that lack a true nucleus and are found in all environments, including extreme ones.

→ It includes both useful and harmful organisms, with examples like Lactobacillus and Rhizobium being beneficial, while some members act as pathogens. Cyanobacteria in this kingdom produce oxygen, and some monerans also play an important role in decomposition and biogas production.

→ Kingdom Protista: It includes unicellular eukaryotic organisms that may or may not have a cell wall. These organisms are mostly found in water or moist environments and are microscopic in nature. Some protists are autotrophic, while others are heterotrophic. They play an important role in aquatic food chains, as some produce oxygen while others serve as food for small organisms. They also help in decomposition and nutrient cycling.

→ Kingdom Fungi: Kingdom Fungi consists of mostly multicellular heterotrophic organisms that have chitin cell walls, although some, like yeast, is unicellular. They are saprophytes that feed on dead and decaying matter and play a key role in decomposing organic waste and recycling nutrients.

→ Some fungi are symbiotic, while others are parasitic and cause diseases. Examples include Yeast, Aspergillus, Penicillium, and mushrooms. Fungi reproduce both sexually and asexually, commonly through spores, and grow best in warm and moist conditions.

→ Kingdom Plantae: It includes multicellular, autotrophic eukaryotic organisms that perform photosynthesis. Their cells have a rigid cell wall made of cellulose that provide strength and protection. These organisms prepare their own food through photosynthesis, act as primary producers in ecosystems, and play a vital role in oxygen production and food chains.

→ They are classified into five major groups: Thallophyta, Bryophyta, Pteridophyta, Gymnosperms, and Angiosperms.

→ Thallophyta (Algae)-Primitive plants:
Thallophyta includes simple and primitive plants with an undifferentiated body called a thallus, lacking true roots, stems, or leaves. They are mostly found in aquatic or moist habitats, absorb nutrients directly from their surroundings, and an example is Spirogyra.

→ Bryophyta – Amphibians of Plant Kingdom:
Bryophyta includes small, non-vascular plants that are found in damp and shady places and require water for reproduction, which is why they are called the “amphibians of the plant kingdom.” They show the first adaptation towards land and have simple root-like structures called rhizoids instead of true roots. Their body is slightly differentiated into stem-like and leaf-like parts, and examples include moss and Marchantia.

→ Pteridophyta – First Vascular Plants:
Pteridophyta includes seedless vascular plants that have true roots, stems, and leaves, along with vascular tissues such as xylem for water transport and phloem for food transport. They are more advanced and show adaptation towards land life, but still require water for reproduction and do not produce seeds. An example of pteridophytes is a fern.

→ Gymnosperms — Naked Seed Plants:
Gymnosperms are seed-producing plants with naked seeds that are not enclosed in fruits and are found in cones. They do not require water for fertilisation and are well adapted to dry and cold conditions. Their needle-like leaves help reduce water loss, and examples include pines and cycads.

→ Angiosperms – Flowering Plants: Angiosperms are the most advanced and diverse group of plants that produce flowers and fruits, with their seeds enclosed inside fruits. Flowers help in reproduction while fruits assist in seed dispersal, making them highly successful and widespread across almost all habitats on Earth. They are divided into monocots and dicots.

→ Kingdom Animalia: Kingdom Animalia includes multicellular, heterotrophic eukaryotic organisms that lack a cell wall and depend on other organisms for food. Most animals show locomotion, quick response to stimuli, and coordinated behaviour, which help them find food, escape predators, and interact with their environment.

→ Basis of Classification in Animals: The basis of classification in animals is the presence or absence of a notochord, which is a flexible rod- like structure that provides support to the body.

→ Animals without a notochord are called non-chordates (invertebrates), while animals with a notochord are called chordates. Chordates are further divided into protochordates and vertebrates.

→ Invertebrates- Animals without a notochord:
Invertebrates (non-chordates) are animals that do not have a notochord. They show a wide range of body complexity, from simple to highly advanced forms, and represent gradual evolution in body organisation.

→ Porifera – Simplest Animals: Porifera (pore bearers) are the simplest multicellular animals that lack true tissues and organs and have a body with pores through which water flows, bringing food and oxygen. They are mostly aquatic and sessile (fixed), and water flow helps in nutrition and respiration. Examples include sponges, and they cannot survive on land due to their dependence on water.

→ Cnidaria: Cnidaria are animals with tissue-level of organisation and stinging cells, and they use tentacles for feeding and defence. They have a single opening that functions as both mouth and anus for food intake and waste removal. Examples include Hydra, jellyfish, and corals.

→ Platyhelminthes — Flatworms: Platyhelminthes are flat-bodied animals with bilateral symmetry, meaning their body can be divided into two halves. They are dorsoventrally flattened and show directional movement. Many are parasitic and have hooks and suckers for attachment.

→ Nematoda – Roundworms: Roundworms have elongated, cylindrical bodies that allow efficient movement in soil, water, or inside hosts. They show a more advanced body plan with two openings (mouth and anus) and organ-system level of organisation. Separate sexes are usually present, showing further development.

→ Annelida: Annelida are segmented worms with organ-system level of organisation and a true body cavity. Their body is divided into segments, which allows better movement and flexibility. They show efficient movement and have a well- developed nervous system. Examples include earthworms.

→ Arthropoda: This group includes insects, crabs, and spiders. They have jointed appendages and a hard external skeleton (exoskeleton) that provides protection, prevents water loss, and supports movement. Their segmented body parts are specialised for different functions, allowing them to survive in diverse environments.

→ Mollusca: Mollusca are soft-bodied animals, often protected by a hard shell in many species, and show organ-system level of organisation. Their body is divided into a head, a muscular foot, and a hump. Examples include snails, octopus, and squid.

→ Echinodermata – Spiny Skin Animals:
Echinodermata are marine animals with spiny skin and an internal skeleton made of calcium carbonate, and they lack a notochord. Examples include starfish and sea urchins.

→ Protochordates: Protochordates are primitive chordates that have a notochord in at least one stage of their life and show early features of chordates. They have a basic internal support structure, and an example is Amphioxus.

→ Vertebrates: Vertebrates are advanced animals with a backbone (vertebral column) that protects the spinal cord and supports the body. They have well-developed organ systems and show complex behaviour and coordination. Vertebrates are divided into fish, amphibians, reptiles, birds, and mammals based on habitat, reproduction, and body covering.

→ Adaptations as Outcomes of Structural Change: The diversity in animals is a result of structural changes over long periods of time. Different features help organisms survive in their environments, such as fins and gills in fish for aquatic life, feathers and hollow bones in birds for flight, fat storage in camels for desert survival, and thick fur in polar bears for cold regions. In mammals, the presence of mammary glands helps in nourishing and protecting the young ones, increasing their chances of survival.

→ Hierarchical Classification: Classification of organisms follows a step-by-step system from broader groups to more specific ones. As we move to lower levels, organisms share more similarities. The main levels are Kingdom → Phylum → Class → Order → Family → Genus → Species.

→ Binomial Nomenclature: Scientific naming, or binomial nomenclature, is a universal system introduced by Carolus Linnaeus to avoid confusion caused by different local names for the same organism. In this system, each organism is given a scientific name made of two parts: the genus and the species. For example, the tiger is named Panthera tigris, where Panthera is the genus and tigris is the species. A species includes organisms that can interbreed and produce offspring.

→ Rules for Writing Scientific Names: The scientific names are written following specific rules.

• Each name has two parts: genus and species.
• The genus name begins with a capital letter and is written first, followed by the species name, which is written in lowercase letters.
• When printed, the scientific name is written in italics and underlined when handwritten.

→ Fossils as Evidence: Fossils are preserved remains or traces of ancient organisms found in layers of rocks, sand, or mud. They provide evidence of how life has changed over time and act as natural records of past life. Older rock layers contain simpler organisms, while newer layers show more complex organisms. Fossils help scientists understand evolution and study past life forms.

→ Biodiversity Under Threat: Biodiversity is essential for maintaining ecological balance, but it is under threat due to human activities causing its rapid decline. Activities such as pollution, deforestation, overuse of resources, and climate change are harming biodiversity. The loss of one species can affect many others, leading to an imbalance in ecosystems and possible extinction.

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Reproduction How Life Continues Class 9 Notes Science Chapter 11

Reviewing Class 9 Science Notes and Exploration Chapter 11 Reproduction How Life Continues Class 9 Notes regularly helps in retaining important facts.

Class 9 Science Chapter 11 Reproduction How Life Continues Notes

Class 9 Science Exploration Chapter 11 Notes

Class 9 Science Chapter 11 Notes – Class 9 Reproduction How Life Continues

→ Reproduction: It is a biological process by which all living organisms give rise to new individuals of their own species.

• Offspring usually resemble their parents because genetic material, called genes, is passed down to guide development.
• Genes act like instructions inside every cell, directing how an organism grows and functions.
• Reproduction not only ensures the continuation of each species but also allows life to adapt and exist in new forms.

→ Two Types of Reproduction: sexual and asexual.

→ Asexual Reproduction: When a single parent is involved in the formation of a new individual, without the fusion of gametes, it is called asexual reproduction. It involves repeated mitotic divisions. Various types of asexual reproduction are: vegetative propagation, binary fission, fragmentation, budding, etc.

→ Vegetative propagation: It is a method of reproduction where new plants grow from vegetative parts like root, stem, or leaf.

→ Natural examples: Sweet potato (root), potato and ginger (stem), Bryophyllum (leaf).

→ Artificial methods: Cutting (sugarcane), layering (lemon, jasmine), grafting (rose), tissue culture.

→ This method is quick and easy, requires only one parent, produces many plants in a short time, ensures identical offspring, and saves energy as no seeds are needed.

→ Tissue Culture: A method of plant propagation using the shoot tip (apical meristem) to produce many healthy, disease-free plants (e.g., banana). It improves yield and is a form of asexual reproduction.

→ Budding: Asexual reproduction where a small bud forms on the parent by cell division, grows, and detaches to live independently, e.g., yeast, Hydra.

→ Rhizopus (bread mould): It grows on decaying bread as white cotton-like fuzzy patches. These organisms can survive harsh conditions (heat, dryness) and germinate into new organisms under favourable conditions like moisture and darkness.

→ Clones: Genetically identical offspring produced from a single parent through asexual reproduction, having the same DNA and characteristics as the parent.

→ Sexual Reproduction: It is the process in which male and female gametes fuse to form a new individual. It involves two parents of opposite sexes of the same species. During reproduction, DNA copies itself, but the copies are not exactly identical, which leads to variation.

→ In sexual reproduction, variation occurs due to the mixing of genes from two parents during meiosis and fertilisation. This makes offspring genetically different and helps in adaptation, survival, and evolution (e.g., lactose intolerance, high-altitude adaptation).

→ Chromosomes: Thread-like structures in the nucleus that carry genetic information. Humans have 23 pairs (46 total), with one chromosome in each pair inherited from each parent.

→ Gametes: Haploid reproductive cells formed by meiosis and used only for reproduction.

→ Meiosis: A special type of cell division that forms gametes by reducing the chromosome number from diploid to haploid. Each gamete receives 23 chromosomes (one from each pair).

→ In animals, the gametes are sperm (male) and egg (female), while in plants, pollen grains carry male gametes and the ovule contains female gametes.

→ Sexual Reproduction In Flowering Plants:
Flowering plants, known as angiosperms, are the most diverse group of plants on Earth. In these plants, flowers act as reproductive organs, while some non-flowering plants, such as pines, also reproduce sexually.

Parts of a flower: A flower has four main parts, which help in plant reproduction:
1. Sepals: Green outer part that protects the flower bud.
2. Petals: Colourful parts that attract insects for pollination.
3. Stamen (male part):

• Anther: produces pollen
• Filament: supports the anther

4. Pistil/Carpel (female part):

• Stigma: receives pollen
• Style: connects stigma to the ovary
• Ovary: contains ovules (develop into seeds)

→ Pollination: The transfer of pollen grains from the anther to the stigma of a flower by agents like wind, water, insects, etc. It is of two types:

• Self-pollination: Transfer of pollen grains from the anther of a flower to the stigma of the same flower.
• Cross-pollination: Transfer of pollen from the anther of one flower to the stigma of another flower of the same plant or a different plant of the same type.

→ Pollinators: Organisms that transfer pollen from one flower to another, helping in plant reproduction. They can be biotic and abiotic agents.

• Biotic agents like insects, birds, and animals ensure effective pollination by carrying pollen while feeding.
• Abiotic agents like wind and water help plants that lack bright flowers or nectar.
• Wind carries light pollen (e.g., maize), while water helps in aquatic plants like Vallisneria.

→ Fertilisation in plants and seed formation:

• Fusion of male and female gametes is called fertilisation, which occurs when the male gamete reaches the ovule through the pollen tube, forming a zygote (fertilised egg).
• After fertilisation, the zygote develops into an embryo. The ovule becomes a seed with a protective seed coat, and the ovary develops into a fruit.
• The seed contains the future plant (embryo), which develops into a seedling when environmental conditions are favourable. This process is called germination.

→ Sexual Reproduction in Animals: It involves fusion of male and female gametes and may occur by asexual or sexual methods in different organisms.

→ External Fertilisation: In aquatic animals like frogs and fish, fertilisation occurs outside the body in water. Eggs and sperm are released into water, but many offspring are lost due to external factors.

→ Internal Fertilisation: In reptiles, birds, and mammals, fertilisation occurs inside the female body, providing better protection and higher survival chances for the offspring.

→ IVF or In-vitro Fertilisation: Fertilisation takes place outside the body in a laboratory.

→ Test-tube Baby: Zygote formed by IVF is developed for a few days and then placed in the uterus, where full development occurs. Fish, amphibians, and insects lay many eggs with less yolk. Their larvae hatch early and feed on their own (e.g., frog, butterfly).

• Reptiles and birds lay eggs with enough yolk to nourish the embryo.
• In mammals, the embryo develops inside the mother’s body.
• Post-hatching/post-birth care is provided by parents. This care helps in the protection, nourishment, and survival of young ones.

→ Reproduction in Human Beings: After puberty is attained, in females, the ovaries exhibit a cycle of events at definite intervals. The ovarian follicles grow into mature follicles. Generally, one mature follicle develops to surround one ovum. While in males, organ mature and begin producing sperms.

→ Male Reproductive System: It produces male gametes (sperm) and transfers them to the female body.

• This system has a pair of testes (singular – testis), two sperm ducts called vas deferens, and a penis.
• The testes produce the male gametes called sperm, and a hormone that regulates the sperm production and the physical changes during puberty.
• The vas deferens carry sperm to the penis.
• The penis is used for ejecting sperm and also passing urine.
• The sperm consists of head containing genetic material and a tail that helps the sperm in movements towards the egg in female sex organ.

→ Female Reproductive System: It consists of a pair of ovaries, oviducts (fallopian tubes), uterus, and vagina.

• Ovaries: Produce female gametes called ova (eggs) and hormones that brings changes during puberty.
• Oviducts (fallopian tubes): These tubes connect each ovary to the uterus.
• Uterus: Part where the development of the foetus takes place.
• Vagina: The chamber after the cervix that receives semen during mating and also acts as the birth canal.

→ Gametogenesis: The process by which gametes (sperm and eggs) are formed through meiosis. It takes place in the testes and the ovaries.

• In humans, gametes have 23 chromosomes instead of 46 so that after fertilisation, the zygote has the correct chromosome number.
• In males, gametogenesis produces many small, motile sperm, while in females it produces a single large egg.

→ What happens when a sperm meets an egg?

• The maturing ovum is released from one of the two ovaries every month by the process of ovulation.
• In humans, internal fertilisation occurs. Sperms are highly active and mobile. Millions of sperms are released in the vagina, and they move up through the cervix and uterus.
• In the fallopian tube, only one sperm fertilises the ovum; as a result, a zygote is formed. Zygote begins to divide immediately in the fallopian tube. At the same time, changes occur in the uterus.
• The inner wall of the uterus thickens and becomes rich with blood vessels, prepared to receive the developing zygote.
• Embryo moves to the uterus and gets attached to its thickened inner wall. The close attachment of the embryo to the uterus is called implantation, marking the beginning of pregnancy.

→ What happens when an egg is not fertilised?

• If fertilisation does not occur, the thickened inner wall of the uterus breaks down along with its blood vessels and moves out of the vagina in the form of a bleeding called menstrual flow (Menstruation). This lasts for 3-7 days.
• The menstrual cycle includes ovulation, preparation of the uterus, and menstruation.
• It repeats every 21-35 days (average -28 days).
• It begins at puberty (10-14 years) in girls and continues throughout the reproductive age till menopause (around 50 years).

→ Pregnancy and childbirth:

• After implantation, special tissues develop between the uterine wall and the foetus called the placenta, through which the nutritional, excretory, and respiratory needs of the foetus are met.
• The development of the foetus inside the uterus till birth takes about 9 months.
• The birth of a fully developed foetus occurs as a result of rhythmic contraction of the muscles in the uterus. Post birth, a baby needs special care.
• Breastfeeding is essential as it provides complete nutrition and protects the baby from diseases. Both mother and baby need proper care, including good nutrition, rest, and timely health support.

→ Reproductive Health:

• It includes aspects like:
• Responsible, safe, and satisfying reproductive life.
• Awareness regarding fertility regulation methods, the right, freedom, and choice to control birth.
• Ability to prevent and control sexually transmitted diseases.

→ Sexual Maturity: It is the stage during adolescence when the body becomes capable of reproduction. In boys, sperm production begins, and in girls, menstrual cycles start. However, emotional maturity develops later and involves handling emotions and making responsible decisions.

→ Readiness for sexual activity requires responsible decision-making to avoid unplanned pregnancies and sexually transmitted infections (STIs).

→ Sexually Transmitted Infections (STIs):
Infectious diseases caused by bacteria, viruses, protozoans, and fungi that spread through sexual contact, e.g., gonorrhoea, herpes, genital warts, syphilis, and HIV, which eventually lead to AIDS. Use of condoms helps prevent STIs and also reduces the chances of pregnancy.

→ Methods to prevent unwanted pregnancy:

• Barrier Method: Physical devices such as condoms and vaginal covers are used. They prevent entry of sperm in the genital tract during copulation and also prevent sexually transmitted infections like AIDS, gonorrhoea, and syphilis.
• Chemical Method: Use of a specific drug by females. Oral pills are hormonal preparations. They inhibit the production of gametes by changing hormonal balances. They can cause side effects.
• Intra-Uterine Devices (IUDs): A copper-T is placed safely in the uterus by a doctor or a skilled nurse, which prevents implantation in the uterus. They may irritate the uterus.
• Surgical Methods: A small portion of the vas deferens in males, and the fallopian tube in females, is surgically removed or ligated (tied). It is called a vasectomy in males and a tubectomy in females.

→ Abortion: Removal of an unwanted pregnancy, usually within the first trimester, when the embryo is small. Prenatal sex determination and sex-selective abortion are illegal in India as they disturb the natural sex ratio in society.

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Work Energy and Simple Machines Class 9 Notes Science Chapter 7

Reviewing Class 9 Science Notes and Exploration Chapter 7 Work Energy and Simple Machines Class 9 Notes regularly helps in retaining important facts.

Class 9 Science Chapter 7 Work Energy and Simple Machines Notes

Class 9 Science Exploration Chapter 7 Notes

Class 9 Science Chapter 7 Notes – Class 9 Work Energy and Simple Machines

→ Work: Work is said to be done when a force applied on an object produces displacement in the direction of the force.

→ If a constant force F causes displacement s, then work done W = F × s. More precisely, W = Fs cosθ, where θ is the angle between force and displacement.

→ Work is maximum when force and displacement are in the same direction (θ = 0°) and zero when perpendicular (θ = 90°).

→ Work depends on the effect of force over a distance, not just force alone.

→ SI Unit of Work: The SI unit of work is joule (J). is named after the scientist James Prescott Joule. He studied how mechanical energy and thermal energy are related, and can be converted from one to the other. This helped develop a unified way to understand energy. One joule is defined as the work done when a force of 1 newton moves an object through a distance of 1 metre in the direction of the force. 1 J = 1 N m.

→ Work is a scalar quantity, meaning it has only magnitude and no direction, even though force and displacement are vectors.

→ Zero Work: Work done is zero in three situations. First, when no force is applied (F = 0), so nothing can cause energy transfer. Second, when there is no displacement (s = 0), even if a large force is applied, such as pushing a wall that does not move.

→ Third, when force is perpendicular to displacement, such as centripetal force in circular motion, where force changes direction but does not contribute to motion in that direction.

→ Positive Work: Work and displacement are in the same direction ( θ between 0° and 90°). In this case, force helps motion and increases the object’s energy.

→ Examples include pushing a cart or wheelchair forward or gravity acting on a falling object. Positive work generally increases kinetic energy.

→ Negative Work: Work is negative when force acts opposite to displacement (θ between 90° and 180°). In this case, force opposes motion and removes energy from the system. Examples include friction slowing down a moving object or a goalkeeper stopping a moving ball. Negative work reduces kinetic energy.

→ Work-Energy Theorem: The work-energy theorem states that the net work done on an object equals the change in its kinetic energy.
W_net = ∆K = K_final – K_initial. This means work is net final internal directly responsible for changing motion. If
positive work is done, kinetic energy increases; if negative work is done, kinetic energy decreases.

→ Energy: Energy is the capacity to do work. It is the ability of a system or object to cause change, especially to apply force and produce motion. Energy exists in many forms such as mechanical, heat, light, chemical, and electrical. The SI unit of energy is joule, same as work. Energy is also a scalar quantity and cannot be created or destroyed, only transformed.

→ Kinetic Energy (K): Kinetic energy is the energy possessed by a body due to its motion. It depends on mass and velocity. The formula is K =\(\frac{1}{2}\) mv².

→ This shows that kinetic energy increases with the square of speed, so doubling speed increases kinetic energy four times. Faster and heavier objects have more kinetic energy.

→ Potential Energy (U): Potential energy is stored energy due to position or configuration. Gravitational potential energy is U = mgh, where m is mass, g is acceleration due to gravity, and h is height above reference level. It represents energy stored due to height. Other forms include elastic potential energy stored in stretched or compressed objects like springs.

→ Mechanical Energy: Mechanical energy is the sum of kinetic energy and potential energy of an object. M.E. = K.E. + P.E. It represents total energy due to motion and position. In ideal conditions without non-conservative forces like friction, mechanical energy remains constant.

→ Gravitational Potential Energy: It is the energy possessed by an object due to its position above the surface of the Earth. It is equal to the work done in lifting the object against the force of gravity.

→ Conservation of Mechanical Energy: The law of conservation of mechanical energy states that when only conservative forces (like gravity) act, total mechanical energy remains constant. As an object falls, potential energy decreases while kinetic energy increases by the same amount.

→ However, in real life, friction and air resistance convert some mechanical energy into heat, so total mechanical energy is not strictly conserved.

→ Power (P): Power is the rate of doing work or rate of energy transfer. It is given by P= W/t. A higher power means more work is done in less time. The SI unit is watt (W), where 1 watt = 1 joule per second. Power can also be expressed as P = F υ when force and velocity are in the same direction.

→ Simple Machines: Simple machines are devices that make work easier by changing the magnitude or direction of force. They do not reduce total work but help by allowing effort to be applied more conveniently. Examples include levers, pulleys, and inclined planes. They help by increasing force or changing its direction.

→ Mechanical Advantage: Mechanical advantage (MA) is the ratio of load (output force) to effort (input force). MA = Load / Effort. A machine with MA greater than 1 multiplies force, making it easier to lift or move heavy objects. When Mechanical Advantage is less than 1, the machine does not provide force gain. Instead, it provides a gain in speed or distance. Therefore, more effort is required to move the load, but the load moves faster or over a larger distance.

→ Pulley: A pulley is a grooved wheel with a rope used to lift loads. A fixed pulley changes the direction of force but has MA = 1. A movable pulley reduces effort required and provides MA greater than 1. Combined pulley systems (block and tackle) can greatly increase mechanical advantage.

→ Inclined Plane: An inclined plane is a sloping surface used to raise objects with less force. Mechanical advantage is MA = L/ h, where L is the A box being pushed up the ramp length of slope, and h is height. A longer slope reduces required effort but increases distance traveled. It trades force for distance.

→ Lever: A lever is a rigid bar that rotates around a fixed point called the fulcrum. It works on the principle of moments: effort × effort arm = load × load arm. Mechanical advantage is MA = effort arm/load arm. A longer effort arm reduces required force.

→ Classes of Levers: Class I levers have fulcrum in the middle, such as scissors or seesaws. They can multiply force or speed depending on arrangement. Class II levers have load in the middle, such as a wheelbarrow or bottle opener, and always multiply force. Class III levers have effort in the middle, such as tweezers or broom, and they increase speed but require more effort.

→ Energy Conservation in Machines: Machines do not create energy; they only transform it from one form to another or transfer it from one point to another. In ideal machines, work input equals work output. In real machines, some energy is lost due to friction, heat, and sound, so efficiency is always less than 100 percent.
Efficiency = (output work/input work) × 100%.

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Another Peek Beyond the Point Class 7 Worksheet with Answers Maths Chapter 4

Teachers can assign these Class 7 Ganita Prakash Worksheet and NCERT Class 7 Maths Chapter 4 Another Peek Beyond the Point Worksheet with Answers Pdf for daily practice.

Another Peek Beyond the Point Worksheet Class 7

Class 7 Maths Another Peek Beyond the Point Worksheet

Worksheet On Another Peek Beyond the Point Class 7 – Another Peek Beyond the Point Class 7 Ganita Prakash Worksheet

Multiple Choice Questions

Question 1.
The value of 0.36 × 2.5 is
(a) 0.09
(b) 0.9
(c) 9
(d) 90
Answer:
(b) 0.9 D

Question 2.
If 48 × 125 = 6000 then 4.8 × 1.25 equals
(a) 0.6
(b) 6
(c) 60
(d) 600
Answer:
(b) 6

Question 3.
Which of the following products is less than 1?
(a) 0.2 × 5
(b) 0.04 × 25
(c) 0.125 × 8
(d) 0.5 × 0.5
Answer:
(d) 0.5 × 0.5

Question 4.
If 24 + x = 96 then x is equal to
(a) 0.25
(b) 0.4
(c) 4
(d) 0.04
Answer:
(a) 0.25

Question 5.
The value of 6.48 ÷ 0.12 is
(a) 5.4
(b) 54
(c) 0.54
(d) 540
Answer:
(b) 54

Question 6.
How many decimal places will ÷ the quotient of 5 + 16 have?
(a) 1
(b) 2
(c) 3
(d) More than 3
Answer:
(d) More than 3

Question 7.
If the product of two decimals has 3 decimal places, which could be the numbers?
(a) 2.3 × 4
(b) 0.45 × 0.5
(c) 1.25 × 0.4
(d) 0.125 × 0.8
Answer:
(b) 0.45 × 0.5

Question 8.
In which of the following will the product be less than both numbers?
(a) 4.2 × 3
(b) 0.8 × 6
(c) 0.6 × 0.3
(d) 5 × 0.4
Answer:
(c) 0.6 x 0.3

Question 9.
Which division will never end?
(a) 5 + 8
(b) 3 + 20
(c) 7 + 9
(d) 11 + 25
Answer:
(c) 7 + 9

Assertion and Reason-based Questions.

1. Assertion (A) The product of two decimal numbers can be a whole number. Reason (R) Decimals are representations of fractions.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Answer:
(b) Both A and R are true but R is not the correct explanation of A.

2. Assertion (A) 18 ÷ 0.3 is greater than 18.
Reason (R) Dividing a number by a decimal number less than 1 decreases the quotient.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Answer:
(c) A is true but R is false.

3. Assertion (A) 9 + 0.09 = 100
Reason (R) Multiplying dividend and divisor by 100 does not change the
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Answer:
(a) Both A and R are true and R is the correct explanation of A.

4. Assertion (A) 1 + 7 gives a repeating decimal.
Reason (R) The remainders repeat in a fixed cycle.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Answer:
(a) Both A and R are true and R is the correct explanation of A.

Fill in the blanks

1. If 6.25 × 16 = 100 then 0.625 × 1.6 = _____
Answer:
1

2. A ribbon is 1.35 m long. The total length of 8 such ribbons is ____ m.
Answer:
10.8

3. The area of a rectangle with length 6.4 cm and breadth 2.75 cm is _____ sq cm.
Answer:
17.06

4. If the thickness of one sheet is 0.18 mm then the height of a stack 45 sheets is ____ mm.
Answer:
8.1

5. If 48.75 ÷ 5 = 9.75 then 487.5 ÷ 5 = ____
Answer:
97.5

6. To convert 3.6 ÷ 0.12 into division with a whole number divisor, both dividend and divisor must be multiplied by ____
Answer:
100

7. The quotient of 125 ÷ 0.25 is ______
Answer:
500

8. When dividing by 8, regrouping from hundredths leads to ______
Answer:
thosandths

9. If the divisor is a decimal less than 1, the quotient is generally ____ than the dividend.
Answer:
greater

10. The decimal representation of 1 + 11 _____
Answer:
0.090909

State whether the following statements given below are True or False.

1. The product of a decimal and a natural number is always greater than the decimal.
Answer:
False

2. 0.6 × 0.4 is less than both 0.6 and 0.4.
Answer:
True

3. Shifting the decimal point in both factors equally does not change the product.
Answer:
False

4. If the sum of decimal places in two numbers is 5 then the product must have exact 5 decimal places.
Answer:
False

5. The quotient of a division can be greater than the dividend.
Answer:
True

6. If dividend and divisor are multiplied by the same number, the quotient remains unchanged.
Answer:
True

7. While dividing by a decimal, only the divisor needs to be changed into a number.
Answer:
False

8. The quotient of 3.75 + 15 has fewer decimal places than the dividend.
Answer:
False

Complete the following table

Question 1.
Complete the following table, one has been done for you.

Decimal Multiplication	Product without Decimal	Product with Decimal
3.24 × 0.06	324 × 6 = 1944	0.1944
0.075 × 4.8	___ × ___ = ___	______
12.5 × 0.032	___ × ___ = ___	______
0.004 × 0.25	___ × ___ = ___	______

Answer:

Decimal Multiplication	Product without Decimal	Product with Decimal
3.24 × 0.06	324 × 6 = 1944	0.1944
0.075 × 4.8	75 × 48 = 3600,	0.34
12.5 × 0.032	125 × 32 = 4000,	0.4
0.004 × 0.25	4 × 25 = 100,	0.001

Question 2.

Complete the following table

Decimal Number + 10 +100	÷ 10	÷ 100
(i) 63.48
(ii) 9.205
(iii) 0.736
(iv) 0.084

Answer:

Decimal Number + 10 +100	÷ 10	÷ 100
(i) 63.48	6.348	0.6348
(ii) 9.205	0.9205	0.00736
(iii) 0.736	0.0736	0.09205
(iv) 0.084	0.0084	0.00084

Very Short Answer Type Questions

Question 1.
State whether 0.6 × 0.9 is less or greater than 0.9.
Answer:
Less than

Question 2.
How many decimal places are there in product 0.45 × 4.2?
Answer:
3

Question 3.
Convert \(\frac{9}{40}\) into decimal.
Answer:
0225

Question 4.
Does \(\frac{7}{125}\) never end? Also, find the quotient.
Answer:
No, it ends (terminates). Quotient = 0.056.

Short Answer Type Questions (2 marks each)

Question 1.
Evaluate (a) 5.82 + 10 (b) 9800 + 1000
Answer:
(a)0.582
(b) 9.8

Question 2.
Solve 9.6 + 4 .
Answer:
2.4

Question 3.
Find 7.2 + 0.6 .
Answer:
12

Question 4.
A metal wire of length 3.35 m is cut into 5 equal pieces. Find the length of each piece.
Answer:
0.67m

Question 5.
A shopkeeper buys 2.75 kg of sugar at ? 46.8 per kg and sells it at ? 52.5 per kg. Find the profit.
Answer:
15. 675

Question 6.
Explain with examples when the product of two decimals is
(a) greater than both numbers.
(b) less than both numbers.
Answer:
(a) When both decimal numbers are greater than 1.
(b) When both decimal numbers are less than 1.

Question 7.
A vehicle travels 96.6 km using 4.2 litres. Find the mileage.
Answer:
23 km/L

Long Answer Type Questions

Question 1.
Given that 25 × 15 = 37 5, find the products.
(a) 25 × 1.5
(b) 25 × 0.15
(c) 2.5 × 1.5
(d) 0.25 × 0.15
(e) 0.025 × 0.015
(f) 2.5 × 15
Answer:
(a) 37.5
(b)3.75
(C) 375
(d) 0.0375
(e) 0.000375
(f) 37.5
Product less than 1 Cases (d) and (e).

Question 2.
In which of the cases above is the product less than 1?
(ii) Find the quotients.
(a) 24.6 + 0.12
(b) 7.56 + 0.04
(c) 9.375 + 0.125
(d) 18.2 + 0.35
(e) 6.48 + 0.16
(f) 4.5 + 0.075
Answer:
(a) 205
(b) 189
(c) 75
(d) 52
(e) 40.5
(f) 60

Case Based Question

Shivani goes to a grocery store. She buys 2.5 kg of apples at ₹ 48.6 per kg and 1.2 kg of grapes at ₹ 72.5 per kg.
Based on the above information, Answer the following Questions.
(i) Find the cost of apples.
(ii) Find the cost of grapes.
(iii) Find the total amount Shivani has to pay.?
Answer:
(i) ₹ 121.50
(ii) ₹ 87
(iii) ₹ 208.50

Activity

Question 1.
Decimal Operations in Daily Life
A school organize a healthy drinks day to promote good eating habits. The canteen sells fresh fruit juice in the following quantities.
• Small cup : 0.25 L
• Medium cup : 0.50 L
• Large cup : 0.75 L

Ravi buys 2 medium cups and 1 small cup of juice.
Answer the following.
(i) Calculate the total quantity Ravi buys.
(ii) The juice is stored in a 2 L container. Find the quantity of juice left after Ravi’s purchase.
(iii) If Ravi had chosen one large cup instead of one medium cup, would the total quantity be more or less?

Question 2.
Decimal Operations in Daily Life : The School Decorators
The student council is decorating the school stage for an annual event. They are using rolls of ribbon of different lengths.
• Red Ribbon : 1.25 m
• Blue Ribbon : 2.50 m
• Gold Ribbon : 3.75 m
The decorating team uses 3 rolls of Red ribbon and 1 roll of Blue ribbon to frame the main banner.

Answer the following.
(i) Calculate the total length of ribbon used for the banner.
(ii) The team started with a total of 10.00 m of starting to tie the ribbons together. If they used 6.25 m of that string, how much string is left?
(iii) If the team had used one gold ribbon instead of Blue ribbon, would the total length be more or less?

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Geometric Twins Class 7 Worksheet with Answers Maths Chapter 1

Teachers can assign these Class 7 Ganita Prakash Worksheet and NCERT Class 7 Maths Chapter 1 Geometric Twins Worksheet with Answers Pdf for daily practice.

Geometric Twins Worksheet Class 7

Class 7 Maths Geometric Twins Worksheet

Worksheet On Geometric Twins Class 7 – Geometric Twins Class 7 Ganita Prakash Worksheet

Multiple Choice Questions

Question 1.
Which of the following is not a criterion for congruence of triangles?
(a) SAS
(b) ASA
(c) SSA
(d) SSS
Answer:
(c) SSA

Question 2.
Which congruence criterion do you use in the following case?
Given,
ZX = RP,
RQ = ZY,
∆PRQ = ∆XZY.
So, APQR s AXYZ.
(a) ASA rule
(b) SSS rule
(c) RHS rule
(d) SAS rule
Answer:
(d) SAS rule

Question 3.
In the given figure, AF = CD and ∠AFE = ∠CDE. If EF = 5 cm then ED is equal to

(a) 6 cm
(b) 5 cm
(c) 8 cm
(d) 10 cm
Answer:
(b) 5 cm

Question 4.
In the given figure, if PM = QM, ∠SMP = ∠RMQ and ∠RPQ = ∠SQM. Therefore, ∆PMR = ∆QMS by which congruence rule?

(a) SSS
(b) SAS
(c) ASA
(d) None of these
Answer:
(c) ASA

(v) In ∆ABC, if BC = AB and ∠B = 80° then ∠A is equal to
(a) 80°
(b) 40°
(c) 50°
(D) 100°
Answer:
(c) 50°

Assertion and Reason-based Questions.

1. Assertion (A) In ∆ABC and ∆PQR, if ∠A = 30°, ∠C = 70°, AB = 5 cm, ∠P = 30°,
∠R = 70° and QR = 5 cm then ∆ABC = ∆PQR.
Reason (R) If three sides of one triangle are equal to the three corresponding sides of another triangle then the two triangles are congruent.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Answer:
(b) Both A and R are true but R is not the correct explanation of A.

2. Assertion (A) In ∆ABC, if AB = AC and ∠C = 48° then ∠A – 64°.
Reason (R) Angles opposite to equal side of an isosceles triangle are equal.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Answer:
(d) A is false but R is true.

Fill in the blanks

1. Two triangles are said to be congruent, if pairs of corresponding sides and the corresponding ______ are equal.
Answer:
angle

2. When the hypotenuse and one side of one right-angled triangle are respectively equal
to the hypotenuse and one side of the other right-angled triangle, the triangles are congruent. This is called ______ congruence of triangles.
Answer:
RHS

3. If two angles and the non-included side of one triangle are respectively equal to the two angles and the non-included side of the other triangle then the triangles are congruent by ______ congruence criterion.
Answer:
AAS

4. In ∆ABC, if AB = AC and ∠B = 40° then find ∠A.
Answer:
100°

State whether the statements given below are True or False.

1. If three sides of a triangle are equal to the corresponding sides of another triangle then the triangles are congruent.
Answer:
True

2. If two legs of a right-angled triangle are equal to two legs of another right-angled triangle then the right-angled triangles are congruent.
Answer:
True

3. If two triangles are congruent then the corresponding sides are equal.
Answer:
True

4. In ∆PQR, if PQ = PR and ∠P = 130° then ∠R = 70°.
Answer:
False

Match the following columns

Column I	Column II
If two sides and the included angle are equal in two triangles.	(a) ASA rule
If all three corresponding sides of two triangles are equal.	(b) SAS rule
If two angles and included side of two triangle are equal.	(c) SSS rule
In two right-angled triangles, hypotenuse and one side of two triangles are equal.	(d) RHS rule

Answer:

Column I	Column II
If two sides and the included angle are equal in two triangles.	(b) SAS rule
If all three corresponding sides of two triangles are equal.	(c) SSS rule
If two angles and included side of two triangle are equal.	(a) ASA rule
In two right-angled triangles, hypotenuse and one side of two triangles are equal.	(d) RHS rule

Very Short Answer Type Questions

Question 1.
In the given figure, if ∆ABC ≅ ∆PQR then find the value of x.

Answer:
4

Question 2.
In the following figure, show that ∆ABO = ∆ACO.

Answer:
Do Yourself

Question 3.
In a ∆ABC, AB = 5 cm, AC – 5 cm and ∠A = 50° then find ∠B.
Answer:
65°

Question 4.
In the given figure, if AB = AC, ∠ACB = 55° and ∠PAB = x then find the value of x.

Answer:
110°

Short Answer Type Questions

Question 1.
Give any two real-life examples for congruent shapes.
Answer:
Candy of the same type and same brand.
Soap of the same type and same brand.

Question 2.
In ∆ABC and ∆PQR, it is given that ∠A = ∠R, ∠C = ∠P and ∠B = ∠Q check both triangles are congruent or not.
Answer:
No

Question 3.
In an isosceles triangle, prove that the altitude from the vertex bisects the base.
Answer:
Do Yourself

Question 4.
If ∆DEF = ∆PQR, write the part(s) of ∆PQR that correspond to
(a) ∠F
(b) ∠E
(c) EF
Answer:
(a) ∠R
(b) ∠Q
(c) QR

Question 5.
∆DEF and ∆LMN are both isosceles with DE = DF and LM = LN, respectively.
If DE = LM and EF = MN then are the two triangles congruent? Which congruence criterion do you use? If ∠E = 40°, what is the measure of ∠N?
Answer:
Yes by SSS Criteria 40°

Question 6.
In the given figure, state the three pairs of equal parts in ∆ABC and ∆EOD. Is ∆ABC ≅ ∆EOD? Why?

Answer:
Yes by SSS Criteria

Question 7.
If ∆ABC ≅ ∆RPQ, ∠A = 60°, ∠B = 50° then find ∠P, ∠Q and ∠R.
Answer:
∠p = 50°
∠Q = 70°
∠R = 60°

Question 8.
∆ABC ≅ ∆DEF such that AB = DE, AC = DF and BC = EF. Find x and y on the basis of the data provided in the given figures.

Answer:
x = 45°
y = 30°

Long Answer Type Questions

Question 1.
In the following figure, ∆ABC and ∆DCB are right angled at A and D, respectively and AC = DB. Prove that ∆ABC = ∆DCB.

Answer:
Do yourself

Question 2.
In the following figure, PA ⊥ AB, QB ⊥ AB and PA = QB. Prove that ∆OAP ≅ ∆OBQ.

Answer:
Do yourself

Question 3.
In the given figure, state the three pairs of equal parts in ?ABC and ?DCB.

(a) Is ∆ABC ≅ ∆DCB? Why?
(b) Is AB = DC? Why?
(c) Is AC = DB? Why?
Answer:
(a) Yes, by ASA criteria
(b) Yes, by CPCT
(c) Yes, by CPCT

Question 10.
Rohan is an aspiring architect. He is observing a railway bridge made of steel beams. He notices that the structure is composed of several triangular sections. He focuses on one particular section, where two triangles, ∆ABC and ∆PQR are used to support a heavy load.
His supervisor informs him that these two triangles are exactly the same in shape and size, meaning that ∆ABC = ∆PQR under the correspondence A P, B Q and C R.
(i) If the length of side AB = 5 cm and BC = 7 cm, what must be the length of side PQ?
(ii) Rohan measures ∠ABC to be 60° and ∠BAC to be 80°. What is the measure of ∠PRQ.
(iii) Which congruence criterion would Rohan use if he only knew that AB = PQ, AC = PR and ∠BAC = ∠QPR?
Answer:
(i) 5 cm
(ii) 40°
(iii) SAS

Activity

Question 1.
Mirror Triangles
Rohan has a rectangular garden ABCD with a diagonal AC.

Answer the following questions.
(i) Identify the pair of congment triangles in rectangle ABCD.
(ii) Write the congruence statement correctly.
(iii) Which congruence rule is used?

Question 2.
Right Triangle Test
Shivam draw a right angled triangle with hypotenuse and one side of triangle are 5 cm and 4 cm, respectively and asked his friend to construct the same using the same data.
Answer the following questions from the given information.
(i) Are both triangles congruent?
(ii) Which parts are equal in both triangles?
(iii) Name the congruence rule used.

The post Geometric Twins Class 7 Worksheet with Answers Maths Chapter 1 appeared first on Learn CBSE.

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Tissues in Action Class 9 Notes Science Chapter 3

Reviewing Class 9 Science Notes and Exploration Chapter 3 Tissues in Action Class 9 Notes regularly helps in retaining important facts.

Class 9 Science Chapter 3 Tissues in Action Notes

Class 9 Science Exploration Chapter 3 Notes

Class 9 Science Chapter 3 Notes – Class 9 Tissues in Action

→ Cell: The smallest unit of life that makes up all living organisms. Cells carry out all basic life functions.

→ Organisms: All living things are called organisms. They may be unicellular (Amoeba) or multicellular (plants and animals).

→ Tissue: A group of cells that are similar in structure and function. Different types of tissues together form organs, different organs group together, forming organ systems; these systems further form a complete organism.

→ a Plants and animals differ in nutrition and tissue functions. Animals have tissues for digesting food, while plants have tissues that help them utilise solar energy for photosynthesis to make their own food. Both have tissues for transport, but their growth patterns differ due to different types of growth tissues.

→ Plant Tissues: Specialised tissues that help plants synthesise food through photosynthesis, transport water and nutrients, provide support,
and control growth.

→ Plants grow in different ways-by increasing length (height of stem and depth of roots), increasing girth (thickness of stem), and regrowing after being cut or grazed.

→ Based on the dividing capacity, plant tissues are of two types: meristematic tissues and permanent tissues.

→ Meristematic Tissues: Consist of actively dividing cells. Meristematic tissues are of three types:

• Apical meristem: Growth zones present at the tips of stems and roots. Its main function is to help the plants grow in length.
• Lateral meristem: Present on the lateral sides of the stems and roots. It increases the girth of stems and roots.

→ Intercalary meristem: Present at the base of internode or near the nodes. It helps in the longitudinal growth of plants, gives bushy appearance (as in grasses) after cutting.

→ Differentiation: A process by which meristematic tissue becomes specialised to perform specific functions. Meristematic tissue becomes permanent by this process.

→ Permanent Tissues: Formed from meristematic tissues, the cells in the tissue that loose the ability to divide. These are specialised to perform functions such as support, transport, and storage.

→ Permanent tissues are of two types:
Protective Tissue-Epidermis: Outermost layer of plant body, made of a single layer of tightly packed, flat, and rectangular cells. It protects plants from mechanical injury, water loss, harmful microorganisms, and extreme environmental conditions.

→ Cuticle: Cells are covered with a waxy layer called cuticle, which reduces water loss and provides protection against injury and parasites.

→ Epidermal Projections-Root Hairs and Stomata: Hair-like projections arise from epidermal cells. Root hairs increase surface area for absorption of water and minerals from the soil. In leaves, the epidermis has small pores called stomata. Stomata in leaves help in gaseous exchange and transpiration.

→ Transpirations: Evaporation of water vapour through stomata creates a transpiration pull in xylem for water transport and helps in elimination of wastes from the plant body.

→ Permanent tissues are divided into two categories: Supporting Tissue-Simple permanent tissue: Consists of only one type of cells.

→ There are three types of simple permanent tissues:

1. Parenchyma: Composed of living cells with relatively thin cell walls that are loosely packed, leaving intercellular spaces between them. Its main function is storage. Aquatic plants have specialised parenchyma with air spaces, helping them float.
2. Collenchyma: Composed of living and elongated cells with cell walls irregularly thickened at the corners. Very little intercellular spaces are present. It provides mechanical support and flexibility to plant. It helps in bending of leaves and stems.
3. Sclerenchyma: Composed of long, narrow, and thick-walled cells. This tissue is made up of dead cells and there are no intercellular spaces. Sclerenchyma cells are present in stems, leaf veins, seeds, nuts, husk of coconut, fibres of jute, etc.

• Conducting Tissues-Complex permanent tissue: Made up of more than one type of cells.

→ There are two types of complex permanent tissues:

• Xylem: Conducts water and minerals from the roots to the different parts of the plant and provides strength to the plant. It is composed of four different types of cells: tracheids, vessels, xylem parenchyma and xylem fibres. Tracheids and vessels have a thick-walled tubular structure. The only living component among these is the xylem parenchyma.
• Phloem: Conducts food material from the leaves to the different parts of the plant. It is composed of four different types of cells: sieve tubes, companion cells, phloem parenchyma and phloem fibres. Sieve tubes transport food; companion cells monitor the loading and unloading of sugars. Materials like food, resin, tannins and latex are stored by phloem parenchyma. Phloem fibres support the sieve tubes.

→ Plant tissues are organised into three tissue systems:

• Dermal tissue system: Forms the outer covering of the plant. Protects the inner parts and reduces water loss.
• Ground tissue system: Forms the main body of the plant between the dermal and vascular tissues. Includes parenchyma, collenchyma, and sclerenchyma.
• Vascular tissue system: Consists of conducting tissues: xylem and phloem.

→ Animal Tissues: Specialised tissues help animals digest food, transport nutrients, provide flexibility for movement, and control growth. Animal tissues are classified into four types based on the functions they perform:

1. Epithelial
2. Connective
3. Muscular
4. Nervous.

→ Epithelial Tissues: Form the covering of the external surfaces, internal cavities and organs of the animal body. Various types of epithelial tissues are:

• Simple squamous epithelium: Single layer of thin, flat cells. Helps in rapid diffusion of liquids and gases. Located in the lining of blood vessels and lungs.
• Stratified squamous epithelium: Many layers of cells; outer cells are flat and tightly packed. Protects underlying tissues from mechanical injury, friction, and entry of microbes. Located in the skin, mouth, and oesophagus.
• Glandular epithelium: Cells specialised for producing and releasing substances; may be cuboidal or columnar. Produces and secrets mucus, enzymes, hormones, sweat, and saliva. Located in salivary glands, sweat glands, and stomach lining.
• Sensory epithelium: Specialised receptor cells with hair-like cilia. Performs smell, taste, sound, and balance functions. Located in nostrils, taste buds, and inner ear.
• Columnar epithelium: Single layer of tall, pillar-like cells, often with hair-like structures. Efficient uptake of nutrients and water. Located in the lining of small intestine.

→ Connective Tissues: Specialised to connect various body organs. Various types of connective tissues are:

• Blood: Has a fluid matrix called plasma, in which red blood corpuscles (RBCs), white blood corpuscles (WBCs) and platelets are suspended.
• Bone: Forms the framework of the body. It is a hard, strong and non-flexible tissue. Bone cells are embedded in a hard matrix that is composed of calcium and phosphorus compounds.
• Cartilage: Has a soft, jelly-like matrix; provides flexibility and cushioning.
• Tendons: Connect muscles to bones.
• Ligaments: Connect bones to bones and prevent excessive movement.

→ Voluntary Movements: Movements that occur under conscious control, e.g., running, writing, lifting objects.

→ Involuntary Movements: Movements that occur automatically, e.g., movement of food in the intestine, heartbeat.

→ Muscular Tissues: The main function of muscular tissues is to provide movement to the body.

→ Muscular tissues are of three types:

• Striated muscles or skeletal muscles or voluntary muscles: Skeletal muscles are attached to the skeleton and made of bundles of long, cylindrical muscle fibres that are unbranched, multinucleate, and striated (show light and dark bands).
• Smooth muscles: Smooth muscle cells are spindle-shaped, have a single nucleus, lack striations, and help in slow, continuous movements like digestion.
• Cardiac muscles: Found only in the heart. Fibres are cylindrical, branched, with a single nucleus and faint striations. Work rhythmically and tirelessly, enabling the heart to beat continuously without fatigue.
• Nervous Tissue: Forms the body’s control and coordination network. Controls reflex actions, memory, and responses. The brain acts as the control centre, coordinating activities of muscles and other organs.
• Neurons (Nerve Cells): Specialised to receive, process, and transmit messages.

→ Structure of a Neuron:

• Cell body: Contains the nucleus; controls cell activities.
• Dendrites: Receive signals from other neurons.
• Axon: Long fibre that carries messages away from the cell body to axon terminals, which transmit messages to other cells.

• Musculoskeletal System: Made up of bones, muscles, joints, cartilage, tendons, and ligaments. Helps in standing upright, movement, maintaining posture, and protecting delicate organs. It functions under the control of the nervous system.
• Joints: Junctions between two or more bones that allow movement. Joints themselves do not move bones; muscles cause the movement.

→ Types of Joints:

• Ball and socket joint: Rounded bone fits into a shallow hollow bone. It allows forward, backward, sideways, and circular movements. Found in shoulder and hip.
• Hinge joint: Moves in one direction like a door hinge. Found in elbow and knee.
• Pivot joint: Allows rotational movement. Found between skull and backbone; enables head to turn side to side.
• Fixed joints: Bones are tightly joined and cannot move. Found in skull; protects brain, eyes, and ears.
• Skeletal System: Framework of bones that provides strength and protects delicate internal organs. Includes skull, vertebral column, and rib cage.

→ Backbone or Vertebral Column (Spine): Made of a series of small bones called vertebrae. Supports the body, helps in standing upright, and allows bending and twisting. Cartilage discs between vertebrae act as cushions and provide flexibility.

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