PART - 2 - Unit V : CH - 16 Excretory Products and Their Elimination — BIOLOGY STD 11 Science — Question

Ria went to see the zoo in her town with her parents and saw many wild animals, their food habits, behaviour, etc. She saw that there was a wide variety of animal life in the zoo. But she was amazed to see that the board placed in front of lion cage and monkey place which tells that both were mammals. However, she thought that they were totally different in appearance.

1. Why lions and monkeys are considered to be mammals?
2. Explain the scientific reason to maintain a zoological park.
3. Is there any similar place to see a variety of plants? If any, then name some.
4. What values are shown by Ria?

Nutan's grandfather read in the newspaper that, for predicting the identity of criminals or for deciding the controversies regarding biological parents of the child, court always asks for DNA test. He wanted to know the procedure behind it. So, asked Nutan about DNA as she was studying biology in class XI. She replied that it is a substance present in the cells of living organisms which store the information about an individual.

1. According to you, what is DNA? And what percentage of DNA varies from one individual to the other?
2. What are the main constituents of DNA?
3. Why are biologists interested in studying human genome?
4. What values are reflected from Nutan's grandfather behaviour?

Compare mitral valve and semilunar valve.

Give atleast three points of differences between spring wood and autumn wood.

What is special about tissue present in the heart?

Mention the basis of a (biological) classification. What educative advantage do we get from r botanical garden and r zoological park?

Why does atrial systole always precede ventricular systole?

Kritika's biology teacher explained the different phases of plant growth in her class. She taught that growth of plants takes place in three successive steps or phases from germination to maturation phase. Kritika reached home and asked her elder sister, a biology post-graduate student to clarify the phases in detail. Kritika's sister told her that she will explain the complete process with the help of experimentation. She took few seeds of pea and germinated them on a circular filter paper, soaked with water in a petri-dish. After two days of growth, she picked up a couple of seedlings with straight radicle and marked it from tip to base with the help of a waterproof ink and again placed the seedlings on moist filter paper to allow them to grow.

1. Mention different phases of growth in plants?
2. List the conditions required for growth.
3. What values are reflected from nature of Kritika's sister?

In the figure, some parts of alimentary canal of cockroach are shown. Name the organs A, B and C. State the function each of these organs.

Give the chemical name of one example of each of the following and mention one function of each of them:

1. Natural auxins.
2. Synthetic auxins.
3. Gaseous plant hormones.