PART - 1 - Unit I : CH - 4 Animal Kingdom — BIOLOGY STD 11 Science — Question

What is the benefit of cell walls, in plant cells?

What is periderm? How does periderm formation take place in the dicot stems?

Give answer for the following:

1. Female pelvis is larger and has a broader front than male pelvis. Why?
2. Name the different curves of vertebral column.
3. What is a seasmoid bone? Name it.
4. Which bones have become modified to form ear ossicles?

Explain the basic structure of an Amino acid.

Succinic dehydrogenase is an enzyme that causes the substrate, succinate, to breakdown into fumarate.
Malonate is a substance that resembles succinate and inhibits the activity of succinic dehydrogenase.

1. State the type of inhibition of succinic dehydrogenase by malonate.
2. Explain how this type of inhibition affects the activity of the enzyme.

What is the basic body plan of animals?

In a given habitat we have 20 plant species and 20 animal species. Should we call this as ‘diversity’ or ‘biodiversity’? Justify your answer.

What is an artificial pacemaker? Explain.

Prakhar, a class XI student went out after rains in the garden. He saw earthworms on the ground and wondered how they are able to move, eat and perform various function of life Next day, he went to his biology teacher and asked her about the same. Her biology teacher politely explained him about how different animals have various levels of organisation of cells. She also told her that except sponges and coelenterates, all the animals of the kingdom-Animalia have organ- system level of organisation.

1. What kind of body organisation are present in sponges and coelenterates?
2. Write about the organisation type in lower animals, like protozoans.
3. In which phylums organ system level organisation is found?
4. What values are shown by Prakhar?

While teaching cell division in the class, teacher told that during meiosis, the chromosome number is reduced to half of the parent, whereas during mitosis, the number remains the same. Seema was not able to recognise what teacher explained in the class and asked her elder brother, a botany student, the need of reducing chromosomes during gamete formation and what will happen if chromosome number will not reduced to its half. He explained the concept in detail to Seema.

1. In which part of the organisms does meiosis occur?
2. How does meiosis help in evolution?
3. Give the significance of meiosis.
4. What value is expressed in the behaviour of Seema's elder brother?