Science (English Medium) कक्षा १२ - CBSE Important Questions for Biology

How have transgenic animals proved to be beneficial in production of biological products?

How have transgenic animals proved to be beneficial in chemical safety testing?

GEAC stands for ______.

What is mutualism?

Construct an age pyramid which reflects a stable growth status of human population.

Apart from being a part of the food chain, predators play other important roles. Mention any two such roles supported by examples.

Study the graph given below and answer the questions that follow :

(i) Write the status of food and space in the curves (a) and (b).
(ii) In the absence of predators, which one of the two curves would appropriately depict the prey population?
(iii) Time has been shown on X-axis and there is a parallel dotted line above it. Give the significance of this dotted line

How does an age pyramid for human population at given point of time helps the policy-makers in planning for future.

"Analysis of age-pyramids for human population can provide important inputs for long-term planning strategies." Explain.

State Gause’s Competitive Exclusion Principle.

Describe the mutual relationship between fig tree and wasp and comment on the phenomenon that operates in their relationship.

Define the following term:

Commensalism

What is an age-pyramid?

Mention any two examples where the organisms involved are commercially exploited in agriculture.

What is commensalism?

What is brood parasitism? Explain with the help of an example.

Write the best method to measure the population density of a single Banyan tree in comparison to Partlzenium weeds in a forest by an ecologist. Explain and justify your answer.

“It is often said that the pyramid of energy is always upright. On the other hand, the pyramid of biomass can be both upright and inverted.” Explain with the help if examples and sketches.

How are productivity, gross productivity, net primary productivity and secondary productivity interrelated ?

The primary productivity in an ecosystem is expressed as ______.

1. gm^-2 yr^-1
2. gm^-2 yr
3. Kcal m^-2 yr^-1
4. Kcal m^-2