Periodic Classification of Elements — Science STD 10 — Question

From the internet, gather information about the chromosome numbers of five animals and five plants. Correlate the number with the size of organism and answer the following questions.

1. Do larger organisms have more number of chromosomes/ cells?
2. Can organism with fewer chromosomes reproduce more easily than organisms with more number of chromosomes?
3. More the number of chromosomes/ cells greater is the DNA content. Justify.

Name the two types of mammalian gametes. How are these different from each other? Name the type of reproduction they are involved in. Write the advantage of this type of reproduction.

What do you mean by a precipitation reaction? Explain by giving examples.

Some hunters are roaming in the plush green forest of Africa. They spot a deer and kill it. They decide to roast the deer there and then and eat it. When the hunters had just finished enjoying the feast of roasted deer, a lion attacks them. The lion kills one of the hunters and eats his flesh.

1. Write a food chain which provides food to lion in this case.
2. Which animal (other than deer) the lion could look for food if he did not get the hunter as prey?
3. Which other animal in the forest could have been in place of lion?
4. How does the above food chain differ form the food chain such as: plants → goat → man?

Distinguish between a convex and a concave mirror.

Explain in brief the reason for each of the following:

1. Advanced sun-rise.
2. Delayed sun-set.
3. Twinkling of stars.

State the 10% law, associated with the flow of energy in trophic levels of organisms.

What is meant by acquired and inherited traits? Explain with one example each.