CBSE Class 7 Revision Assignment Set 04

Holiday Assignment

Reading Skill

Computer Viruses

Question 1. Answer these questions.
a. What is a computer virus?
Answer: A computer virus is a small program written to copy itself into other computer files. It gets executed automatically whenever the infected file is used and destroys data and other programs residing in the computer storage media.
In simple words: A computer virus is a harmful program that copies itself and damages computer data.

Exam Tip: Always mention that it is a program that self-replicates and destroys data.

Question 1(b). What harm does it do to the computer?
Answer: A computer virus destroys data and programs residing in the computer storage media, causes system crashes, and can paralyze a large computer system within a few minutes.
In simple words: It deletes important files and can crash the whole system.

Exam Tip: Highlight terms like data destruction and system crashes.

Question 1(c). How does the virus infect the computer?
Answer: A virus attaches itself to other computer programs, situates itself into the computer memory, gets executed automatically, and copies its instructions into all other programs running on that computer. It also spreads through floppy disks, memory storage devices, computer networks, emails, the Internet, and other online systems.
In simple words: It attaches to good programs, copies itself, and spreads via storage devices or the internet.

Exam Tip: Mention both self-replication in memory and transmission via external media or networks.

Question 2. Find words from the passage which mean the same as:
a. carried out
Answer: Executed
In simple words: Executed means performed or carried out.

Exam Tip: Look for verbs in the text related to performing tasks.

Question 2(b). information
Answer: Data (or instructions)
In simple words: Data refers to stored information.

Exam Tip: Associate information with data or files in technical contexts.

Don’t Take English for Granted

Question 1. Answer these questions.
a. What are the strengths of the English language?
Answer: The strengths of the English language include being the most widely used language in the world, spoken by one in every seven human beings, and possessing the largest vocabulary with as many as two million words.
In simple words: English is spoken globally by many people and has a huge vocabulary.

Exam Tip: Quote the statistics given in the text (one in seven speakers, two million words).

Question 1(b). Give any two examples to show that English is a crazy language.
Answer: Two examples showing that English is a crazy language are: 1) There is no egg in eggplant, neither pine nor apple in pineapple, and no ham in hamburger. 2) Quicksand works slowly, boxing rings are square, and a guinea pig is neither a pig nor from Guinea.
In simple words: Words have meanings or parts that do not match their names, like pineapples having no pine or apple.

Question 1(c). What is the difference between "a wise man" and "a wise guy"?
Answer: While both phrases use the root word "wise", they differ entirely in meaning and connotation in common usage, where a wise man denotes someone with profound wisdom, whereas a wise guy often implies a smart-aleck or cocky person.
In simple words: A wise man is truly intelligent, while a wise guy is sarcastic or cheeky.

Exam Tip: Emphasize the contrasting colloquial meanings of similar phrases.

Question 1(d). Which example of the peculiarity of the English language, given in the passage, did you find most amusing?
Answer: The example of having noses that run and feet that smell is one of the most amusing peculiarities, as physical body parts are assigned action verbs metaphorically.
In simple words: The funny idea that noses run and feet smell.

Exam Tip: Personal response questions should be supported with a brief reason from the text.

Question 1(e). What does the writer mean when he says "English was not invented by computers"?
Answer: The writer means that English is quirky, illogical, full of human creativity, and irregular because it was shaped by human beings over centuries rather than being programmed with strict logical rules by machines.
In simple words: English is full of human quirks and inconsistencies, not machine-like logic.

Exam Tip: Relate the phrase to human creativity and linguistic irregularities.

Question 2. Find words from the passage, which mean the same as:
a. shelter
Answer: Asylum
In simple words: An asylum provides shelter or refuge.

Exam Tip: Look for institutional or protective housing terms.

Question 2(b). supervise
Answer: Oversee
In simple words: To oversee means to supervise or manage.

Exam Tip: Check prefix antonym pairs mentioned in the text.

Question 2(c). illogical; not sensible or practical
Answer: Insane (or crazy)
In simple words: Crazy or insane describes something completely illogical.

Exam Tip: Match descriptive adjectives with text vocabulary.

Writing Skill & Creative Tasks

Question 3. You are on 'The Planet Pollutonia'. You have been elected to be the President of the planet, but the planet has many problems. Everyday there is terrible smog and traffic jams there. The rivers are dirty and the fish are dying. The water is not good to drink. The air is difficult to breathe and there is garbage everywhere. How will you solve this problem? Write your solution in about 120-140 words.
Answer: As the newly elected President of Planet Pollutonia, my topmost priority is restoring ecological balance and ensuring the health of all citizens. To combat terrible smog and traffic congestion, I will immediately ban petrol and diesel vehicles, replacing them with electric public transport and mandatory bicycle lanes. Factories emitting toxic smoke will be heavily fined and required to install air scrubbers. To clean our dying rivers and contaminated water supply, I will establish advanced wastewater treatment plants and strictly penalize industrial dumping. A massive waste-management revolution will be launched: every household must segregate garbage, and recycling plants will convert waste into energy. Finally, a nationwide tree-plantation drive, 'Green Pollutonia', will purify our air. Together, through strict laws and community participation, we will transform Pollutonia into a green, breathable paradise.
In simple words: As President, I will introduce electric transport, clean the rivers, stop factory smoke, and enforce recycling to save the planet.

Exam Tip: Structure creative essays with a clear introduction, actionable bullet points or steps, and an optimistic conclusion.

SCIENCE

Ch: Levels of Organization

Question 1. What is a cell?
Answer: A cell is the basic structural and functional unit of all living organisms. It is often called the building block of life.
In simple words: A cell is the smallest living part of all living things.

Exam Tip: Remember the standard definition: structural and functional unit of life.

Question 2. Who discovered the cell?
Answer: Robert Hooke discovered cells in 1665 when he observed a thin slice of cork under a primitive microscope.
In simple words: Robert Hooke discovered cells using a microscope on cork.

Exam Tip: Associate Robert Hooke with cork and the year 1665.

Question 3. What is photosynthesis? Explain.
Answer: Photosynthesis is the process by which green plants prepare their own food using carbon dioxide and water in the presence of sunlight and chlorophyll, releasing oxygen as a byproduct. The chemical representation is: \(6CO_2 + 6H_2O \xrightarrow{\text{Sunlight/Chlorophyll}} C_6H_{12}O_6 + 6O_2\).
In simple words: Plants make food using sunlight, water, and carbon dioxide.

Question 4. What is the function of Red Blood Cells?
Answer: Red Blood Cells (RBCs) contain hemoglobin, a protein that binds with oxygen in the lungs and transports it to all the cells and tissues of the body while helping carry carbon dioxide back to the lungs.
In simple words: RBCs carry oxygen from the lungs to the rest of the body.

Exam Tip: Highlight hemoglobin and oxygen transport.

Question 5. What is a microscope? Who developed the first simple microscope?
Answer: A microscope is an optical instrument used to view objects that are too small to be seen by the naked eye. Antonie van Leeuwenhoek developed the first practical simple microscope.
In simple words: A microscope magnifies tiny objects; Leeuwenhoek made the first simple one.

Exam Tip: Distinguish between Robert Hooke (cell discovery) and Leeuwenhoek (advanced simple microscope / living cells).

Question 6. Name the largest and the smallest single cell.
Answer: The largest single cell is the egg of an ostrich, and the smallest single cell is a Mycoplasma (or PPLO - Pleurovirus-like organism / bacterium).
In simple words: Ostrich egg is the biggest cell; Mycoplasma is the smallest.

Exam Tip: Memorize ostrich egg (largest) and bacteria/Mycoplasma (smallest).

Question 7. Which is the longest, hardest and the strongest bone in the human body?
Answer: The femur (thigh bone) is the longest, heaviest, and strongest bone in the human body.
In simple words: The thigh bone (femur) is our strongest and longest bone.

Exam Tip: Remember Femur = thigh bone.

Question 8. Draw a flow chart to show the levels of organization.
Answer: Cell \(\rightarrow\) Tissue \(\rightarrow\) Organ \(\rightarrow\) Organ System \(\rightarrow\) Organism.
In simple words: Cells make tissues, tissues make organs, organs make systems, and systems make the whole body.

Exam Tip: Use arrows to show hierarchical progression clearly.

Question 9. Prepare a list of organs which makeup the following systems.
(a) Nervous system
(b) Circulatory system
(c) Excretory system
(d) Digestive system
Answer:
(a) Nervous system: Brain, spinal cord, and nerves.
(b) Circulatory system: Heart, blood vessels (arteries, veins, capillaries), and blood.
(c) Excretory system: Kidneys, ureters, urinary bladder, and urethra.
(d) Digestive system: Mouth, esophagus, stomach, small intestine, large intestine, liver, and pancreas.
In simple words: Each system is made of specific organs working together.

Exam Tip: List at least 2-3 core organs for each body system.

Question 12. Make a power point presentation on structure of a cell. Differentiate between a Plant cell and an Animal cell.
Answer:
Plant Cell: Has a rigid outer cell wall made of cellulose, contains chloroplasts for photosynthesis, has a large central vacuole, and is generally rectangular in shape.
Animal Cell: Lacks a cell wall (has only a cell membrane), lacks chloroplasts, has multiple small vacuoles, and is irregular or round in shape.
In simple words: Plant cells have walls and chloroplasts; animal cells do not.

Exam Tip: Focus on cell wall and chloroplasts as the key differences.

Ch: Force and Motion

Question 1. Define Force.
Answer: Force is a push or pull applied on an object that can change its state of motion, speed, direction, or shape.
In simple words: Force is a push or pull that moves or stops things.

Exam Tip: Always include both push and pull in the definition.

Question 2. What are the effects of Force?
Answer: The effects of force include: 1) It can move a stationary object or stop a moving object. 2) It can change the speed of a moving object. 3) It can change the direction of motion. 4) It can change the shape and size of an object.
In simple words: Force can start motion, stop motion, change speed, change direction, or change shape.

Exam Tip: List at least three distinct physical effects.

Question 3. Differentiate between Contact and Non Contact Force?
Answer: Contact Force: Forces that act only when objects are in direct physical contact with each other (e.g., muscular force, frictional force).
Non-Contact Force: Forces that act from a distance without any direct physical contact between objects (e.g., gravitational force, magnetic force, electrostatic force).
In simple words: Contact forces need touching; non-contact forces work from a distance.

Exam Tip: Provide suitable examples for each category.

Question 4. What is Friction? What are the two types of Friction? Explain.
Answer: Friction is the opposing force that comes into play when one surface moves or tends to move over another surface. Two main types of friction are:
1) Static Friction: Friction acting when an object is at rest on a surface.
2) Sliding/Kinetic Friction: Friction acting when an object slides over a surface.
In simple words: Friction is the rubbing force that slows down moving things.

Question 5. What is Pressure? What is its unit?
Answer: Pressure is defined as force acting per unit area (\(P = \frac{F}{A}\)). The SI unit of pressure is Pascal (Pa) or Newtons per square meter (\(\text{N/m}^2\)).
In simple words: Pressure is force divided by the area it acts upon. Unit is Pascal.

Exam Tip: State both the formula and the SI unit.

Question 6. What are the different types of pressure? Explain with examples.
Answer: The major types include atmospheric pressure, liquid pressure, and solid pressure.
1) Atmospheric Pressure: The pressure exerted by the weight of air in the atmosphere (e.g., drinking juice through a straw).
2) Liquid Pressure: The pressure exerted by liquids against container walls, which increases with depth (e.g., water spurting out faster from a lower hole in a bottle).
In simple words: Pressure can be exerted by air (atmosphere) or liquids (water pressure).

Exam Tip: Give real-world examples for clarity.

SOCIAL SCIENCE

History

Question 1. Match the Following -
a. Indian Museum
b. Salar Jung Museum
c. National Philatelic Museum
d. Air Force Museum
Answer:
- Indian Museum \(\rightarrow\) Largest collection of Indian Coins
- Salar Jung Museum \(\rightarrow\) Biggest one-man collection
- National Philatelic Museum \(\rightarrow\) Extensive stamp collection
- Air Force Museum \(\rightarrow\) Records the history of Indian Air Force
In simple words: Matched each museum with its correct specialty.

Exam Tip: Philatelic specifically relates to stamps.

Question 2. Write True or False -
a. Historical evidences are in the form of manuscripts and inscriptions.
b. Manuscripts were printed and written on papers.
c. A historical source is something that tells us about history.
d. All interpretation of the past in the form of books, articles or journals are Primary Sources.
Answer:
a. True
b. False (Manuscripts were handwritten, not printed)
c. True
d. False (Books and articles written later are secondary sources)
In simple words: Manuscripts are handwritten; books written later are secondary sources.

Exam Tip: Distinguish between primary sources (original records) and secondary sources (subsequent interpretations).

Question 3. Fill in the blanks-
a. Museums acquire __________, __________ and __________ heritage. These activities are managed and coordinated by __________.
b. Sulabh International Museum is dedicated to the history and kinds of __________.
c. __________ Museum has a library that contains rare maps and several old manuscripts and books that revealed Mumbai's history.
d. The Louvre's most popular piece is Leonardo Da Vinci's __________.
e. __________ are great source of information about culture and history.
Answer:
a. cultural, historical, natural; government authorities / trust
b. toilets (sanitation)
c. Asiatic Society (or Dr. Bhau Daji Lad)
d. Mona Lisa
e. Inscriptions and manuscripts
In simple words: Filled in missing historical and museum terms.

Exam Tip: Remember iconic museum exhibits like the Mona Lisa at the Louvre.

Civics

Question 1. Explain the following terms.
a. Social inequality
b. Gender inequality
c. Economic inequality
Answer:
a. Social Inequality: Disparities in status, rights, and opportunities among individuals in a society based on caste, class, or religion.
b. Gender Inequality: Unequal treatment or perceptions of individuals based on their gender, usually disadvantaging women and girls.
c. Economic Inequality: Disparity in wealth, income, and financial resources among different sections of society.
In simple words: Inequalities mean unfair differences in social status, gender treatment, or wealth.

Question 2. Identify the type of inequality.
a. Shravan has two children. He allows his son to go to school but makes his daughter sit at home.
b. Mr. X is unable to rent a house due to his religion.
c. Tara is unable to find employment because she belongs to a particular caste.
d. Sakshi's brother feels that girls should not be allowed to drive cars
Answer:
a. Gender inequality
b. Social / Religious inequality
c. Social / Caste inequality
d. Gender inequality
In simple words: Classified each real-life scenario into its specific type of inequality.

Exam Tip: Look for keywords like daughter/son (gender) or religion/caste (social).

Question 3. Write any two instances where you have observed gender inequality in the society.
Answer: 1) Preferential treatment given to male children for higher education and better nutrition compared to female children. 2) Unequal division of household chores where girls are expected to help in domestic work while boys are not required to do so.
In simple words: Examples include favoring boys for schooling or putting all housework on girls.

Exam Tip: Use common social observations from daily life.

Question 4. Education can lead to reduction in poverty in the society. Discuss.
Answer: Education empowers individuals by equipping them with marketable skills, knowledge, and qualifications required for better job opportunities and higher earnings. An educated workforce drives economic productivity, breaks intergenerational cycles of poverty, and fosters awareness of health and rights.
In simple words: Education helps people get better jobs and escape poverty.

Exam Tip: Link education to skill-building and employability.

Geography

Question 1. Fill in the Blanks;
a. ________ are sudden and violent, they cause harm to life and nature.
b. The topmost layer called the ________ is composed of a number of pieces called ________ plates.
c. The ________ is a Dynamic Planet.
d. Rock formed after cooling and solidification of molten magma is called ________.
e. A ________ volcano is formed by alternate layers of lava and rock fragments.
Answer:
a. Earthquakes (or Volcanoes / Natural disasters)
b. crust, tectonic (lithospheric)
c. Earth
d. igneous rock
e. composite (or Stratovolcano)
In simple words: Filled in key geographical terms about Earth's layers and rocks.

Exam Tip: Remember Earth's crust and tectonic plates.

Question 2. Give two examples of each-
a. A Shield volcano
b. An Active volcano
c. Igneous Rocks
d. Metamorphic Rock
e. Earthquake prone zones in India
Answer:
a. Shield volcano: Mauna Loa (Hawaii), Mount Etna (early stages)
b. Active volcano: Mount Etna, Stromboli
c. Igneous Rocks: Basalt, Granite
d. Metamorphic Rock: Marble, Slate
e. Earthquake prone zones in India: Himalayan region, Andaman and Nicobar Islands
In simple words: Provided classic examples for volcanoes, rocks, and earthquake zones.

Exam Tip: Memorize standard geological examples like Basalt (igneous) and Marble (metamorphic).

Question 3. Summarise the theory of Plate Tectonics.
Answer: The theory of plate tectonics states that the Earth's lithosphere is divided into several large and small solid pieces called tectonic plates that float and move slowly over the semi-fluid asthenosphere, causing geological activities like earthquakes, volcanic eruptions, and mountain building at their boundaries.
In simple words: Earth's crust is broken into moving plates that cause earthquakes and volcanoes.

Exam Tip: Mention lithospheric plates moving on the mantle/asthenosphere.

Question 4. Explain with examples, how metamorphic rocks are formed.
Answer: Metamorphic rocks are formed when pre-existing igneous or sedimentary rocks are subjected to extreme heat and high pressure deep within the Earth's crust, altering their mineral composition without melting. Example: Limestone (sedimentary) transforms into marble (metamorphic), and shale transforms into slate.
In simple words: Heat and pressure change old rocks into new metamorphic rocks.

Exam Tip: Highlight the role of intense heat and pressure.

Question 5. Give another name for Strato volcano. How is it formed?
Answer: A Strato volcano is also known as a composite volcano. It is formed by alternate layers of hardened lava flows, tephra, pumice, and volcanic ash erupted over successive explosive periods.
In simple words: Also called composite volcanoes, formed by layers of lava and ash.

Exam Tip: Remember alternative name: composite volcano.

Question 6. Compare and contrast Sedimentary rock with Metamorphic rocks.
Answer:
Sedimentary Rocks: Formed by the accumulation, compaction, and cementation of mineral and organic sediments (e.g., sandstone, limestone). Often contain fossils and are layered.
Metamorphic Rocks: Formed by the transformation of existing rocks under intense heat and pressure (e.g., marble, quartzite). Rarely contain fossils and have crystal structures.
In simple words: Sedimentary rocks form from layers of sediments; metamorphic rocks form from heat and pressure on old rocks.

Exam Tip: Contrast formation mechanisms (sediment accumulation vs. heat/pressure transformation).

Reading Skill

Computer Viruses

A computer virus is a small programme that is written to copy itself into other computer files. It gets executed automatically whenever the infected file is used and destroys data and other programmes residing in the computer’s storage media. (floppy-disks, hard disks, CD’s, pen drives, etc).

A computer virus normally attaches itself to other computer programmes and becomes part of them. A virus programme is written in such a way that it situates itself into the computer’s memory and gets executed automatically. Then it copies the virus instructions into all the other programmes that are being executed on that computer. This activity or process, in computer terms, is called “infecting” the system and the files. The infection can then spread to other computers through floppy disks, memory storage devices, computer networks, emails, the Internet and other online systems. Some viruses are harmless as they display jokes or messages on the screen without damaging the system. On the other hand, viruses can cause crashes (destroying data and programmes) and even a large computer system within a few minutes.

1. Answer these questions.

a. What is a computer virus?

b. What harm does it do to the computer?

c. How does the virus infect the computer?

2. Find words from the passage which mean the same as:

a. carried out .......................................

b. information .......................................

Don’t Take English for Granted

English is the most widely used language in the world. One in every seven human beings can speak English. English has the largest vocabulary, perhaps as many as two million words. English is also a crazy language. There is no egg in eggplant neither pine nor apple in pineappleand no  ham in hamburger. Quicksand works slowly, boxing rings are square and a guinea pig is neither a pig and nor is it from Guinea.

Perhaps all English speakers should be sent to an asylum for the verbally insane. In which language do people recite at a play and play at a recital? Have noses that run and feet that smell? Why do “a wise man” and “a wise guy” differ in meaning? Why are “over look” and “oversee” antonyms? Why are “quite a lot” and “quite a few” alike? English was not invented by computers. It has the creativity of the human race (which is not a race at all). That is why, when stars are out they are visible, but when lights are out they are invisible. And why, when I wind up my watch I start it, but when I wind up this essay, I end it.

1. Answer these questions.

a. What are the strengths of the English language?

b. Give any two examples to show that English is a crazy language.

c. What is the difference between “a wise man” and “a wise guy”?.

d. Which example of the peculiarity of the English language, given in the passage, did you find most amusing?

e. What does the writer mean when he says “English was not invented by computers”?

2. Find words from the passage, which mean the same as:

a. shelter ..................................

b. supervise ..................................

c. illogical; not sensible or practical .................................. Read the novel ‘Tom Sawyer’ and draw a Graphic Organiser to depict the main events in the novel. You can use half a sheet of Chart Paper for the same.

Writing Skill

Write a paragraph in about 100-120 words expressing your feelings as to how you would feel if one day you become famous. You should keep in mind what you would like to be famous for, and why ? You can begin with - When I am famous...

Click on link below to download CBSE Class 7 Revision Assignment Set D