Biodiversity and Conservation — BIOLOGY STD 12 Science — Question

Refer to the figure given below and answer the questions that follow:

1. Recognize and explain the process by which Tasmanian wolf evolved.
2. Give one example of an animal that has evolved along with Tasmanian wolf.
3. Compare and contrast the two animals shown?

Give reasons, why?

1. Cow dung is preferred for biogas production.
2. Saccharomyces cerevisiae is commonly known as baker's yeast.

Arrange the following parts of mammary gland in correct order in which milk secreted from the cells of alveoli of lobes reaches the nipple. Lactiferous duct, mammary duct, mammary tubules, mammary ampulla.

What is the difference between gaseous and sedimentary cycles?

Why is the length of a food chain in an ecosystem generally limited to 3-4 trophic levels? Explain with an example.

Write any four ways used to introduce a desired DNA segment into a bacterial cell in recombinant DNA technology experiments.

Given below are the events that are observed in artificial hybridisation programme. Arrange them in the correct sequential order in which they are followed in the hybridisation programme.
(a) Re-bagging; (b) Selection of parents; (c) Bagging; (d) Dusting the pollen on stigma; (e) Emasculation; (f) Collection of pollen from male parent.

Mrs. Peter and Mrs. James had babies at the same hospital. Mrs. Peter took home a girl, Nancy and Mrs. James received a boy, Richard. However, Mrs. James was certain she gave birth to a girl and brought suit against the hospital. Blood tests showed that Mr. James was type O, Mrs. James was type AB and Mr. and Mrs. Peter were both type B. Nancy was type A and Richard was type O. List the possible genotypes of each individual and then indicate the correct parents for each child.
Genotypes :

1. Mrs. Peter ____________.
2. Mr. Peter ______________.
3. Nancy _____________.
4. Mrs. James _________________.
5. Mr. James ________________.
6. Richard _______________.
7. Whose baby is Nancy?
8. Whose baby is Richard?

Answer the following questions:
Explain sex determination in humans.

During an excursion to a botanical garden, the teacher shows an old tree, which was on the verge of extinction. As soon as the teacher advanced with the students, some enthusiastic students climbed up the tree and started cutting the branches, collecting its leaves as precious collection. Rajesh instead took photographs of the tree from various angles. The boys mocked at Rajesh while the teacher appreciated him.

1. How can biodiversity be conserved?
2. What international initiatives were taken to conserve biodiversity?
3. What values did Rajesh possess?