Reproduction in organisms — BIOLOGY STD 12 Science — Question

Give reasons : There is steady concentration of ozone in the stratosphere.

In the figure, structure of an antibody molecule is shown. Name the parts A, B and C. Show A, B and C in the diagram.

Prior to a sports event blood & urine samples of sportspersons are collected for drug tests.

1. Why is there a need to conduct such tests?
2. Name the drugs the authorities usually look for.
3. Write the generic names of two plants from which these drugs are obtained.

Read the following questions carefully and suggest a suitable word.

1. Small sacs that form a part of male reproductive system and store spermatozoa.
2. Small tubes lying on either sides of uterus near the kidney and carry the egg from the ovary to the uterus.
3. The small erectile organ in females, which lies above the urethral opening and is homologous of glans penis of males.

Following methodology has been used for cattle improvement:

1. Complete the steps a and b in this method.
2. What is the name of this method?
3. What is the importance of this method?

Organisms at a higher trophic level have less energy available. Comment.

Gene therapy is an attempt to correct a genetic defect by providing a normal gene into the individual. By this the normal function can be restored. An alternate method would be to provide the gene product (protein/ enzyme) known as enzyme replacement therapy, which would also restore the function. Which in your opinion is a better option? Give reason for your answer.

Why is solid waste management facing endless problems?

(i) What is hematocrit?
(ii) Mention the term with respect to -
(a) Temporary increase in number of WBCs
(b) Decrease in number of RBCs

What are bioherbicides? Give any two examples.