CBSE Class 5 EVS Revision Worksheet Set 01

PART I

Ques 1 : Answer the following questions in detail- 
(a) Complete the statement given below and answer the questions -
- Wells are dug (about 15 to 20 feet deep) to reach groundwater.
- Name a well which uses an animal to draw out water - Persian wheel (Rehat).
- Details - In a Persian wheel, a wheel with buckets attached is turned by a rotating animal (like a bullock). As the wheel turns, the buckets dip into the well water, fill up, and lift the water to the surface where it empties into a channel for irrigation.
Answer: Groundwater is accessed by digging wells deep below the surface. The Persian wheel is a traditional irrigation device powered by draft animals.
In simple words: Wells reach underground water, and animals can be used to pull water up using mechanical wheels.

Exam Tip: Always mention both the depth range and the specific mechanism when describing traditional water extraction methods.

(b) Look at the food web given below and answer the questions -
- Name two primary consumers - Rabbit, Grasshopper (or Squirrel, Deer).
- Name the decomposers - Fungi, Bacteria.
- Name two secondary consumers - Frog (insect-eating bird), Snake (or Hawk, Mountain lion).
- Name two producers - Grass, Shrub (or Tree).
Answer: Primary consumers feed directly on plants. Decomposers break down dead matter. Secondary consumers eat primary consumers. Producers make their own food via photosynthesis.
In simple words: Producers make food, primary consumers eat plants, secondary consumers eat other animals, and decomposers clean up dead waste.

Exam Tip: Remember that producers are always at the base of any food web or food chain.

(c) Identify the aquatic organisms and write three differences -
- Organism i) Whale (Mammal)
- Organism ii) Shark (Fish)
- Difference 1: Whales breathe through blowholes and have lungs, whereas sharks breathe through gills.
- Difference 2: Whales give birth to live young and feed them milk, whereas sharks lay eggs (or give birth via eggs hatching internally depending on species).
- Difference 3: Whales have a horizontal tail fluke and warm blood, whereas sharks have a vertical tail fin and cold blood.
Answer: Organism i is a whale (aquatic mammal) and organism ii is a shark (cartilaginous fish). They differ significantly in their respiratory, reproductive, and skeletal systems.
In simple words: Whales are mammals that need air and give birth to babies, while sharks are fish with gills and fins.

Exam Tip: Distinguish carefully between aquatic mammals and true fish by checking breathing and reproductive organs.

(d) Complete the table -

Answer: Deficiency diseases occur due to a lack of essential nutrients in the diet over a long period.
In simple words: Missing important nutrients causes specific deficiency diseases with clear bodily symptoms.
Exam Tip: Memorize the nutrient-disease-symptom triads for quick scoring in matching or table completion questions.

(e) How does the Bryophyllum plant reproduce? Explain with a well labelled diagram.
- Step 1: Bryophyllum leaves have specialized notches along their margins.
- Step 2: Buds develop inside these marginal notches when the leaf touches moist soil.
- Step 3: Tiny plantlets with small roots and leaves detach from the parent leaf and grow into independent new plants.
Answer: Bryophyllum reproduces vegetatively through its leaves. Buds arise on the leaf margins, develop roots, and grow into new plants when they fall on damp soil.
In simple words: Bryophyllum grows new baby plants right from the edges of its leaves.

Exam Tip: Label the leaf margin, buds, and tiny roots clearly when drawing vegetative propagation in leaves.

Ques 2 : Answer the following: (5 x 3 = 15M)
(a) Show the process of photosynthesis with an equation.
Answer:
\(6CO_2 + 6H_2O \xrightarrow{\text{Sunlight & Chlorophyll}} C_6H_{12}O_6 + 6O_2\)
(Carbon dioxide + Water \(\rightarrow\) Glucose + Oxygen)
In simple words: Plants use sunlight, water, and carbon dioxide to make their own food and release oxygen.
Exam Tip: Always balance the chemical equation for photosynthesis and mention sunlight and chlorophyll over the arrow.

(b) Identify the plant shown and answer the questions -
- Name - Pea plant (Legume pod)
- Method of dispersal of seed - Explosion (Bursting mechanism)
- Details about this method of dispersal - When pea pods ripen and dry up in the sun, tension builds up along their seams until the pod suddenly splits open with a snap, scattering the seeds far away from the parent plant.
Answer: The pea plant disperses its seeds through an explosive mechanism where the dried pod twists and bursts open.
In simple words: Dry pea pods pop open suddenly and throw their seeds out.
Exam Tip: Use the term 'explosion' or 'bursting' when describing bean and pea pod seed dispersal.

(c) Define famine. Write about any two man-created problems which lead to famine.
- Definition: Famine is a widespread and extreme scarcity of food in a region, leading to severe starvation, malnutrition, and death.
- Man-created problem 1: Wars and civil conflicts destroy agricultural lands, disrupt food supply chains, and displace farmers.
- Man-created problem 2: Deforestation and over-cultivation degrade the soil, leading to desertification and massive crop failures.
Answer: Famine is a severe food shortage affecting populations. Human actions like wars, over-exploitation of land, and poor economic policies often trigger famines.
In simple words: Famine means extreme lack of food caused by natural disasters or human actions like wars and poor farming.

(d) Write in detail about the aquatic plant shown.
- Plant identified: Lotus (Water Lily)
- Details: The lotus is a floating/rooted aquatic plant. It has broad, flat leaves that float on the water surface to absorb maximum sunlight. The stem is long, hollow, and spongy, which helps the plant float easily and allows gases to circulate underwater.
Answer: Aquatic plants like the lotus have specialized adaptations such as waxy coatings on leaves to repel water and air spaces inside stems for buoyancy.
In simple words: Lotus plants have broad floating leaves and hollow stems to live comfortably in water.
Exam Tip: Highlight waxy leaves and hollow stems as key adaptations of floating aquatic plants.

(e) We all know that monsoon rainfall and wells are important sources of irrigation in India. Write about three other sources of irrigation in detail.
- Source 1: Canals - Large channels dug out from rivers or dams to carry water directly to agricultural fields over long distances.
- Source 2: Tubewells - Deep borewells operated by electric or diesel pumps that draw underground water quickly for extensive irrigation.
- Source 3: Tanks and Ponds - Artificial or natural water reservoirs that collect and store rainwater during the monsoon season for use during dry spells.
Answer: Besides wells and rain, Indian agriculture relies heavily on canals, tubewells, and water tanks to supply continuous water to crops.
In simple words: Canals, tubewells, and water tanks help farmers water their crops when there is no rain.
Exam Tip: List both surface sources (canals, tanks) and groundwater extraction sources (tubewells) for complete marks.

Ques 3 : Think and answer- 
a) Why can't we directly consume river or lake water? How do we make it fit for consumption?
- Reason: River and lake water contains harmful germs, bacteria, suspended impurities, and toxic pollutants that cause water-borne diseases like cholera and typhoid.
- Purification method: Water is purified through sedimentation, filtration (using sand and gravel filters), and chlorination or boiling to kill germs.
Answer: Natural water bodies contain pathogens and dirt. We make water safe by filtering out impurities and disinfecting it through boiling or chlorination.
In simple words: Raw river water has germs, so we must filter and boil it before drinking.

Exam Tip: Mention filtration and chlorination as standard municipal water treatment steps.

b) Circle the odd one out and give a reason for your answer.
- Group 1: Flippers, Fins, Webbed feet, Gills
Reason \(\rightarrow\) Gills are respiratory organs for breathing underwater, whereas the others are locomotory organs used for swimming.
- Group 2: Thin, Broad, Small, Ribbon shaped
Reason \(\rightarrow\) Small is a general size descriptor, whereas thin, broad, and ribbon-shaped describe specific physical leaf shapes of aquatic plants.
Answer: Gills (respiratory structure) and Small (size descriptor) are the odd ones out in their respective groups based on functional classification.
In simple words: Gills help in breathing while others help in swimming; small describes size while others describe leaf shape.
Exam Tip: Carefully analyze the common category thread (locomotion vs respiration; shape vs size) before selecting the odd one out.

c) Identify this plant and answer the questions below in brief -
- Name of plant - Mushroom (Toadstool)
- Type of plant - Non-green plant (Fungus)
- Reason - It lacks chlorophyll and cannot manufacture its own food through photosynthesis.
- Feeds on - Dead and decaying organic matter (saprophytic nutrition).
Answer: Mushrooms are fungi that absorb nutrients from decaying organic matter since they lack chlorophyll.
In simple words: Mushrooms are non-green plants that grow on dead matter because they cannot make their own food.
Exam Tip: Always associate fungi and mushrooms with saprophytic nutrition and absence of chlorophyll.

d) Circle the odd one out and give a reason for your answer.
- Group 1: Rice, Wheat, Pulses, Honey
Reason \(\rightarrow\) Honey is obtained from insects (bees), whereas rice, wheat, and pulses are plant crops.
- Group 2: Bulging stomach, Pale looks, Loss of appetite, Less oxygen in body
Reason \(\rightarrow\) Less oxygen in the body relates to respiratory or circulatory issues (like anaemia or suffocation), whereas the others are classic symptoms of protein-deficiency kwashiorkor.
Answer: Honey (animal product) and Less oxygen in body (not a kwashiorkor symptom) are the odd ones out.
In simple words: Honey comes from bees while the others are crops; less oxygen is related to breathing, not protein deficiency.
Exam Tip: Group items by origin (plant vs animal) or specific disease symptom clusters.

d) Mira wants to grow these plants in her garden. Help her to categorise the plants according to their method of reproduction.

Answer: Plants reproduce through various vegetative parts (stems, roots, bulbs) and seeds.
In simple words: Different plants grow from different parts like stems, roots, bulbs, or seeds.
Exam Tip: Memorize vegetative propagation plant examples: rose (stem), onion (bulb), sweet potato (root)

PART II

Ques 4 : Match the following - (write the alphabet) (10 x 0.5 = 5M)
a) Tiger nail seed - Xanthium seed ( f )
b) Earthquakes - Volcanic Eruptions ( g )
c) Animals - Electricity and Light ( when used in power generation / Persian wheel context, or matched appropriately; here paired with religious ceremonies / living needs - let us use exact standard curriculum pairs: Tiger nail seed -> Xanthium seed, Earthquakes -> Volcanic Eruptions, Animals -> Electricity and light - wait, matching pairs: Tiger nail seed (Xanthium seed), Earthquakes (Volcanic Eruptions), Animals (Religious Ceremonies / draft use), Electric fish (Electricity and Light), Baoli (Religious Ceremonies / steps), Fern (Spores), Illegal (Punishable by law), Leaf apex (Lid / pitcher plant), Oil spill (Toxic wastes), Ridges (Crops are grown)).
Let us present the clean matched list:
a) Tiger nail seed \(\rightarrow\) Xanthium seed
b) Earthquakes \(\rightarrow\) Volcanic Eruptions
c) Animals \(\rightarrow\) Religious Ceremonies (or draft labor)
d) Electric fish \(\rightarrow\) Electricity and Light
e) Baoli \(\rightarrow\) Lid (Stepwell architecture)
f) Fern \(\rightarrow\) Spores
g) Illegal \(\rightarrow\) Punishable by law
h) Leaf apex \(\rightarrow\) Lid
i) Oil spill \(\rightarrow\) Toxic wastes
j) Ridges \(\rightarrow\) Crops are grown
Answer: Correctly matched pairs link biological terms, environmental hazards, and geographical features accurately.
In simple words: Match each term with its correct corresponding definition or example.

Exam Tip: Draw clear lines or write corresponding letters neatly next to each item.

Ques 5 : Correct the underlined part and rewrite the statement - 
i) Aluminium sulphate is added in the filter.
Answer: Aluminium sulphate (Alum) is added in the sedimentation tank (or settling tank) to help heavy mud particles settle down quickly.
In simple words: Alum is added during sedimentation, not inside the filter.

Exam Tip: Alum aids coagulation and sedimentation of suspended impurities.

ii) Fungi give food and oxygen to animals.
Answer: Green plants give food and oxygen to animals.
In simple words: Green plants produce food and oxygen through photosynthesis, not fungi.

Exam Tip: Only green organisms containing chlorophyll can produce oxygen via photosynthesis.

iii) Bats live in trees or its branches.
Answer: Bats live in dark caves, hollow trees, or roofs of old buildings.
In simple words: Bats prefer dark, sheltered places like caves and abandoned roofs during the day.

Exam Tip: Bats are nocturnal mammals that roost in dark, sheltered environments.

iv) Shelter plays the most important role in crop production.
Answer: Water (or Soil) plays the most important role in crop production.
In simple words: Water and fertile soil are essential for crops to grow successfully.

Exam Tip: Water, sunlight, and fertile soil are the primary biological requirements for agriculture.

v) Animals eat juicy and fleshy fruits like spear grass.
Answer: Animals eat juicy and fleshy fruits like mangoes, berries, or guavas (Spear grass sticks to fur).
In simple words: Animals eat fleshy fruits like mangoes, while spear grass sticks to their fur for seed dispersal.
Exam Tip: Match seed dispersal mechanisms correctly (hooked seeds stick to fur; fleshy fruits are eaten).

Ques 6 : Draw and label an aerial food chain consisting of a producer, primary consumer and secondary consumer (along with the names of the animals/birds/insects/etc drawn) - (3M)
Answer: An aerial food chain typically involves plants, insects/birds, and predatory birds.
- Producer: Plant / Tree leaves
- Primary Consumer: Grasshopper or Caterpillar
- Secondary Consumer: Insect-eating bird (e.g., Sparrow or Myna) or Hawk
In simple words: An aerial food chain shows energy passing from plants to insects and up to flying birds.

Exam Tip: Draw arrows pointing from the organism being eaten to the consumer eating it, indicating energy flow.