Page 155 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

5. Name the four layers of a forest.

Ans: Emergent layer, crown, canopy, understorey & forest floor.
6. Name two medicinal plants.

Ans: Ashoka & Chandan
7. Which category of organisms makes the first trophic level of every food chain?

Ans: Producers
8. Suman wrote a food chain in the following way :

frog → eagle → insects → grass → snake → Is this chain correct? If not, help Suman
to correct it?

Ans: No.
Grass → Insect → Frog → Snake → Eagle.

F. Short-answer questions
1. What are decomposers and what role do they play in the ecosystem?

Ans: Decomposers break down dead plant and animal remains into simple substances that
mix with the soil. They also break down the waste of other organisms. Decomposers

are very important for any ecosystem. The role of decomposers in a forest is vital
in providing nutrients to the plants. The decayed and decomposed plant or animal

matter converts into an organic substance known as humus that adds the required
nutrients to the soil and makes it fertile.

2. Are there similar kind of trees in every forest? If not, why?
Ans: No, there are not similar kinds of trees in every forest.

Different forests have unique climates, soils & ecological conditions which support
different types of trees adapted to those specific environments. For example, tropical

rainforests have a diverse range of broad leaf evergreens, while boreal forests are
dominated by coniferous trees like pines & spruces.

3. Deforestation may lead to floods. How?
Ans: It is because trees & vegetation play a crucial role in absorbing rain water & reducing

runoff. Without trees, rainwater flows more quickly & directly into rivers & streams,
increasing the risk of overflow & flooding. Additionally, tree roots help to stabilize

soil. Without them, soil erosion can occur, further contributing to flood risk.
4. Differentiate between canopy and crown.

Ans: The upper part or top of a tree is called its crown. It is the part of the tree that have
branches above the stem. Different trees have different shapes of crowns. Pine trees

have tapered crowns, while a neem tree has a round crown.
Below the emergent layer is the canopy that comprises trees of almost equal

heights forming a roof or canopy over the forest. The canopy is so thick mostly that

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