Living Science (2020, 2021) - GeniusJnr

You have read about food chains in this chapter. Each living thing is a part of multiple food chains – for example, grass is a part of the food chain: grass → grasshopper → frog → snake → eagle, and also of the food chain: grass → deer → tiger.
All of the interconnected and overlapping food chains in a habitat make up a food web.



See the given food web and answer these questions.
1. From the food web, construct two different food chains, each with four links.
2. If all the eagles were killed, what would happen to the number of

Deepak carried out an experiment to see the effect of increasing the amount of carbon dioxide available to a pondweed (a submerged plant) on the rate of photosynthesis carried out by the plant. The readings of the experiment are potted in the graph.



Answer these questions.

1. How do you think he measured the rate of photosynthesis?
2. How do you think he increased the amount of carbon dioxide in the water?
3. Since temperature causes a change in the rate of photosynthesis, he kept the temperature constant throughout the experiment. Suggest one more factor that he should have kept constant.
4. Why did the graph increase initially?
5. Why do you think it ultimately levelled off?

Study the diagram. Label the structures A, B and C. What is the function of C? Is this a plant cell or an animal cell? Draw and label 3 extra structures that would change this cell into:
1. a plant cell if it is an animal cell
2. an animal cell if it is a plant cell.

In 1965, Prime Minister Lal Bahadur Shastri gave a simple slogan to the people of India – Jai Jawan Jai Kisan (Hail the farmer, hail the soldier).
What value does this slogan show? Which other people in your life would you like to pay a similar tribute to?

People get injured if a natural calamity such as a tornado strikes. They also get injured in accidents such as a road accident or a fire accident. Often you find people not ready to help the injured persons.
Suppose you see an injured person lying on the road after a road accident. What will you do?

Ramesh studies in Class 10. He says he would like to try alcohol and drugs just to see what they are like. Is he correct in doing this? What advice would you give him?

Other than providing energy to our body, what else is food needed for?

If a new organism is discovered and it is found that it can make food for itself from simple non-living substances found in nature, what will you classify it as–an autotroph or a heterotroph? Give reasons.

Agriculture deals with plants and not with animals. Do you agree? Give reasons.

Water is formed by the chemical combination of hydrogen and oxygen.
A molecule of water consists of 2 atoms of hydrogen and 1 atom of oxygen, combined chemically. Figure 1 represents the molecules in liquid water (black – oxygen atom; gray – hydrogen atom).
                                                                                                                                            

Which of the following represents water molecules after liquid water is vaporized on boiling?

(a)   (b)   (c) 
 

We can see many overweight people but very few overweight animals. Why do you think this is so?

The graph given below shows how the lining of the uterus in a female who has achieved puberty varies with time.
Examine the graph and answer the following questions.



1. What is happening between A and B?
2. Mark the corresponding points in the second menstrual cycle when the same happens.
3. Fertilization occurs on day 16 of the second menstrual cycle. How do you expect the graph to behave after point C? Will the pattern of the first and second months be followed?