CBSE Class 4 Science Green Plants Assignment Set 01

Answer: Chlorophyll is the green pigment in leaves. It traps energy from sunlight for photosynthesis and gives leaves their green colour.

Teacher's Note:
1. Chlorophyll is found in green parts of plants.
2. Without it a plant could not make food.

Answer: Stomata are tiny pores, mostly on the underside of leaves, through which gases are exchanged. Water vapour also leaves the plant through them.

Teacher's Note:
1. The word is plural; one pore is a stoma.
2. Each stoma is surrounded by two bean-shaped guard cells.

Answer: Photosynthesis is the process by which green plants make their own food using carbon dioxide, water and chlorophyll in the presence of sunlight.

Teacher's Note:
1. Food is made mainly in the leaves.
2. Oxygen is released during the process.

Answer: A food chain shows how energy passes in the form of food from one living thing to another. Example: grass → grasshopper → frog → snake.
It begins with a producer (a green plant) and ends with decomposers.

Teacher's Note:
1. Each living thing in the chain is food for the next one.
2. Green plants are the starting point because they make their own food.

Answer: 1. Leaf blade (lamina): the flat green part.
2. Midrib: the main vein in the middle.
3. Side veins: the lines on either side of the midrib.
4. Petiole: the stalk that joins the leaf to the stem.

Teacher's Note:
1. Veins carry water and food through the leaf.
2. The blade is flat so that it can catch plenty of sunlight.

Answer: leaf blade (lamina)

Teacher's Note:
1. It is the widest part of the leaf.
2. Most of the food is made here.

Answer: stomata

Teacher's Note:
1. Gases pass in and out through them.
2. They are too small to see without a microscope.

Answer: Chlorophyll

Teacher's Note:
1. It is a pigment found in leaf cells.
2. It also helps in making food.

Answer: Iodine

Teacher's Note:
1. Iodine solution is brown or orange in colour.
2. It is a common test to show that a leaf has made food.

Answer: a producer (a green plant)

Teacher's Note:
1. Producers make their own food.
2. All other living things depend on them.

Answer: blue-black

Teacher's Note:
1. This colour change shows that starch is present.
2. If there is no starch, iodine stays brown.

Answer: oxygen

Teacher's Note:
1. Oxygen is released during photosynthesis.
2. Animals and humans need it to live.

Answer: Guard cells

Teacher's Note:
1. They open and close the stoma.
2. Each stoma has two guard cells.

Answer: Starch

Teacher's Note:
1. Potatoes and grains store a lot of starch.
2. The stored food is used when the plant needs it.

Answer: Oxygen

Teacher's Note:
1. It leaves the leaf through the stomata.
2. Animals use it for breathing.

Answer: Carbon dioxide

Teacher's Note:
1. It enters the leaf through the stomata.
2. Animals breathe this gas out.

Answer: Carbon dioxide and water

Teacher's Note:
1. Water is taken in by the roots.
2. Carbon dioxide is taken in from the air.

Answer: Petiole

Teacher's Note:
1. It is the leaf stalk.
2. It also carries water into the leaf.

Answer: Carbon dioxide + water → food (glucose/starch) + oxygen

Teacher's Note:
1. Sunlight and chlorophyll are needed but are not used up as raw materials.
2. The food made is later stored as starch.

Answer: Banyan tree

Teacher's Note:
1. Its branches send down hanging roots.
2. It can live for hundreds of years.

Answer: Mango tree

Teacher's Note:
1. Mango is a very popular fruit in India.
2. The tree is a plains plant.

Answer: Coconut palm

Teacher's Note:
1. It grows well in coastal areas.
2. The water inside the fruit is called coconut water.