P-1 Lenses — Science STD 10 — Question

Name and state the law given by Lindeman which tells us how much energy entering a particular trophic level of organisms is available for trasnsfer to the next higher trophic level.

Explain the terms ‘self pollination’ and ‘cross-pollination’?

What were the objections raised against Darwinism?

Read the following extract and answer the questions that follow:
A liberal view behind the concept of organ and body donation is that after death our body should be useful to other needful persons so that their miserable life would become comfortable. Awareness about these concepts is. increasing in our country and people are voluntarily donating their bodies.

Life of many people can be saved by organ and body donation. Blinds can regain their vision. Life of many people can be rendered comfortable by donation of organs like liver, kidneys, heart, heart valves, skin, etc. Similarly, body can be made available for research in medical studies. Many government and social organizations are working towards increasing the awareness about body donation.
1.What is the liberal view behind the organ and body donation?
2.Name any four organs that can be donated.

Describe how an electromagnet could be used to separate copper from iron in a scrap yard.

Write the chemical equation of the reaction which takes place when iron reacts with dilute sulphuric acid. What happens when the gas produced is ignited with a burning matchstick?

Write the characteristics with reference to their classification:
Grasshopper:

A substance X which is used as an antacid reacts with dilute hydrochloric acid to produce a gas Y which is used in one type of fire-extinguisher. Name the substance X and gas Y. Write a balanced equation for the chemical reaction which takes place.

Explain why, we cannot see our seats first when we enter a darkened cinema hall from bright light but gradually they become visible.

State the following statements into chemical equations and then balance them: Iron reacts with sulphuric acid.