CBSE Class 4 EVS Revision Worksheet Set 11

PART I

Q1. Answer the following questions in details:

a) Write any two differences between saline and fresh water. Give examples for both the sources.
Answer: Saline water contains a very high amount of dissolved salts (mainly sodium chloride) and is not fit for drinking or irrigation. Fresh water contains very low amounts of dissolved salts and is suitable for drinking, cooking, and agriculture. Examples of saline water sources include oceans and seas. Examples of fresh water sources include rivers, lakes, ponds, and groundwater.
In simple words: Saline water is salty and found in oceans, while fresh water is drinkable and found in rivers and rain.

Exam Tip: Always mention the salt content and provide clear, distinct natural examples for both types of water to score full marks.

b) Define a symbol and a key in reference to a map. Give suitable examples.
Answer: A symbol is a small sign, drawing, or color used on a map to represent real-world objects or features like rivers, roads, or buildings. A key (or legend) is a small box or list on a map that explains what each symbol, color, or line stands for. For example, a blue line on a map represents a river, and this meaning is explained in the map key.
In simple words: A symbol is a mini picture on a map, and a key tells us what that picture means.

Exam Tip: Remember that maps cannot show actual objects due to lack of space, so standardized symbols and keys are essential for universal understanding.

c) Explain the process of tooth decay with the help of a flowchart:
Answer: Eating food leaves tiny food particles trapped between teeth. Bacteria feed on these leftover food particles and produce harmful acids. These acids gradually attack and destroy the hard outer covering of the tooth called enamel, leading to cavities and tooth decay.
Flowchart representation:
Eating food and leaving particles behind -> Bacteria feed on food particles and produce acid -> Acid attacks tooth enamel -> Formation of cavity (Tooth Decay)
In simple words: Bacteria eat trapped food, make acid, and that acid damages teeth to form holes.

Exam Tip: Practice drawing flowchart steps sequentially with connecting arrows to clearly demonstrate cause and effect.

d) See the pictures and identify the parts of plant and write their functions as seen in the picture here.
Answer:
1. Part: Ginger (Modified Stem / Rhizome). Function: Stores food for the plant and helps in vegetative propagation.
2. Part: Roots (Fibrous/Tap roots in soil or underwater roots). Function: Fixes the plant firmly in the soil and absorbs water and minerals.
3. Part: Potato/Tubers or Bulbs (Modified Underground Stem). Function: Stores reserve food materials like starch for the plant.
In simple words: These plant parts store extra food and help the plant grow and survive.

a. Define a map. Mention one use of it.
Answer: A map is a drawing of the earth's surface, or a part of it, drawn on a flat surface according to a specific scale. One major use of a map is to find directions and locate places easily while traveling.
In simple words: A map is a flat drawing of a place that helps us find our way around.

Exam Tip: Mention both flatness and scale in your definition for completeness.

b. Complete the table.
Answer:

In simple words: Flowers are useful for food, spices, perfumes, and decoration.
Exam Tip: Learn common plant products and their specific culinary or commercial applications.

c. Complete the information on Chipko movement:
Answer: Felling of trees in the Garhwal-Himalayan region caused major soil erosion and floods. In 1973, groups of women from the Chamoli district in Uttarakhand boldly surrounded the trees to prevent the loggers from cutting them down. This movement was led by Sunderlal Bahuguna and Chandi Prasad Bhatt.
In simple words: Brave villagers hugged trees to stop them from being cut down, starting the famous Chipko movement.

d. Name the following:
Answer:
TREES FOUND IN HILLY AREA: 1. Pine, 2. Deodar
TREES GROWN ON ROADSIDE: 1. Neem, 2. Peepal (or Banyan)
In simple words: Pine and Deodar grow in cold hills, while Neem and Peepal provide shade along roads.
Exam Tip: Categorize trees based on their geographical adaptations (climatic regions).

e. Define fog.
Answer: Fog is a thick cloud of tiny water droplets suspended in the atmosphere at or near the earth's surface that greatly reduces visibility.
In simple words: Fog is a low cloud touching the ground that makes it hard to see far ahead.

Exam Tip: Distinguish fog from mist and dew based on altitude and density.

f. Identify the types of teeth drawn below and also write their other names:
Answer:
1) Incisors (Cutting teeth)
2) Canines (Tearing teeth)
3) Premolars (Cracking and grinding teeth)
4) Molars (Grinding teeth)
In simple words: Different types of teeth have different shapes to cut, tear, and grind food.

Exam Tip: Learn both scientific names (Incisors, Canines, Premolars, Molars) and functional names for teeth.

Q3. Think and answer:

i) Why is river water not fit for drinking?
Answer: River water is not fit for drinking because it contains harmful germs, bacteria, dirt, chemical wastes from factories, and sewage dumped into it.
In simple words: River water gets polluted by waste and germs, making it unsafe to drink directly.

ii) Why do doctors advice the fitting of braces for some people?
Answer: Doctors or orthodontists advise braces to correct misaligned, crooked, or overcrowded teeth, ensuring proper bite alignment and easier dental hygiene.
In simple words: Braces straighten crooked teeth so they look good and are easy to clean.
Exam Tip: Proper teeth alignment prevents tooth decay and gum disease by eliminating hard-to-reach spaces.

iii) We cannot survive without tree. Give reason.
Answer: Trees provide oxygen essential for breathing, absorb carbon dioxide, regulate climate, prevent soil erosion, and supply food, medicines, and shelter.
In simple words: Trees give us oxygen to breathe and food to eat, which are necessary for life.

iv) Why are scales important for drawing a map?
Answer: Scales are important because they provide a ratio to represent large distances on the ground into manageable, proportional distances on a small paper map.
In simple words: Scales help show huge distances on a small sheet of paper accurately.
Exam Tip: Define scale as the ratio between map distance and actual ground distance.

v) Why are flowers coloured and have fragrance?
Answer: Flowers are brightly colored and have a sweet fragrance to attract insects, bees, and birds, which helps in the process of pollination.
In simple words: Bright colors and nice smells attract bees and insects to help pollinate flowers.

a. A compass is a place or a thing that you can easily recognize.
Answer: A landmark is a place or a thing that you can easily recognize.
In simple words: A landmark helps us identify locations easily, whereas a compass shows directions.

Exam Tip: Be careful with definitions of geographical navigation tools versus identification markers.

b. The Red Fort in Delhi is shaped like a lotus flower.
Answer: The Lotus Temple in Delhi is shaped like a lotus flower.
In simple words: The Lotus Temple is named and shaped like a lotus, unlike the Red Fort.

c. Tribal people eat fruits of plants like amla, teak, figs.
Answer: Tribal people eat fruits of plants like amla, ber, figs.
In simple words: Teak is a timber-yielding tree, not a fruit-bearing tree like ber or amla.

d. At the age of six humans have 32 permanent tooth.
Answer: At the age of twelve to twenty-one humans have 32 permanent teeth (or: At the age of six humans have 20 milk teeth).
In simple words: Children have milk teeth at age six; permanent teeth come later.

e. Water from a tubewell is used mainly for drinking and evaporation.
Answer: Water from a tubewell is used mainly for drinking and irrigation.
In simple words: Tubewell water is used for drinking and watering crops, not for evaporation.

Match Column 1 with Column 2:

Answer: 1. Water changing into water vapour - Evaporation
2. Water vapour changing into water - Condensation
3. Fibrous root - Millets
4. Tap root - Pea plant
5. Centre of tooth - Pulp
6. Soft pink tissue - Gums
7. Winter - Pansy
8. Spring - Carnation
9. Sketch - Rough map
10. Landmark - Temple
In simple words: Matching scientific and general terms to their correct partners.
Exam Tip: Draw clear lines or write matching numbers next to terms to avoid confusion during matching exercises.

Q3. Draw a neat labelled diagram showing various parts of a leaf. 
Answer:
Steps to draw parts of a leaf:
1. Draw the leaf blade (lamina) as a flat, broad green surface.
2. Draw the central vein (midrib) running down the middle.
3. Draw side veins branching out from the midrib.
4. Draw the petiole (stalk) connecting the leaf to the stem.
In simple words: A leaf diagram should clearly show the stalk, midrib, veins, and edge.

Exam Tip: Always label diagrams using straight horizontal lines and clear capital letters.

Q4. Label the internal structure of a tooth: 
Answer:
(a) Enamel
(b) Dentine
(c) Pulp
(d) Root / Gum
In simple words: The outer layer is enamel, followed by dentine, with soft pulp inside.
Exam Tip: Enamel is the hardest substance in the human body; always label it as the outermost crown layer.

Q5. Identify the symbols given below: 
Answer:
a) River confluence / Stream junction
b) Bridge
c) Post Office (PO) / Settlement buildings
d) Railway track / Broad gauge railway line with level crossing
In simple words: Cartographic symbols represent physical and man-made features on maps.
Exam Tip: Learn standard topographical map symbols for roads, railways, and water bodies.

Q6. Multiple choice questions: 

1. Highlands on maps are represented by ____________ colour.
(a) Green
(b) Brown
(c) Orange
(d) Yellow
Answer: (b) Brown
Brown color is conventionally used on physical maps to depict mountains, hills, and highlands.
In simple words: Brown shows high places like mountains on a map.
Exam Tip: Green represents plains and lowlands, blue represents water bodies, and brown represents highlands.

2. The part where a leaf is attached to the branch is called ____________
(a) Leaf base
(b) Leaf stalk
(c) Petiole
(d) Pedicel
Answer: (c) Petiole
The stalk that attaches a leaf blade to the stem or branch is called the petiole.
In simple words: The petiole connects the leaf to the branch.
Exam Tip: Do not confuse petiole (leaf stalk) with pedicel (flower stalk).

3. These plants have fibrous roots-
(a) Bamboo and neem
(b) Neem and maize
(c) Rose and pea plant
(d) Maize and millets
Answer: (d) Maize and millets
Monocotyledonous plants like maize and millets possess fibrous root systems consisting of thin, moderately branching roots growing from the stem.
In simple words: Grasses like maize and millets have bushy fibrous roots instead of one main taproot.
Exam Tip: Taproots are found in dicot plants (like peas and neem), while fibrous roots are found in monocots (like wheat, maize, and millets).

4. The tongue is ____________
(a) Is a sense organ
(b) Is made of taste buds
(c) Is made of muscles
(d) Both a and c
Answer: (d) Both a and c
The tongue functions as a sensory organ for taste and is composed entirely of flexible skeletal muscles.
In simple words: The tongue is a muscular organ that also helps us taste food.
Exam Tip: When multiple correct options are valid, check for a "Both" choice.

5. Around ____________ percent of our body is made up of water.
(a) 60
(b) 70
(c) 80
(d) 90
Answer: (b) 70
Approximately 70 percent of the human body mass consists of water.
In simple words: About 70% of our body weight is water.
Exam Tip: Remember standard biological statistics like body water percentage.

6. When water vapour condenses on cold objects like grass, ____________ is formed.
(a) Fog
(b) Mist
(c) Water
(d) Dew
Answer: (d) Dew
Water vapor in the air condenses directly into liquid water droplets on cool surfaces like grass and leaves during night time, forming dew.
In simple words: Tiny water drops on grass in the morning are called dew.
Exam Tip: Distinguish dew (formed on ground surfaces) from frost, fog, and rain.

Please refer to attached file for CBSE Class 4 EVS Revision Worksheet (8)