Human Reproduction — BIOLOGY STD 12 Science — Question

Draw a labeled diagram of pistil and describe in brief about each part.

Expand the following and explain any one of them:

1. IVF
2. ZIFT
3. MTP

How did Louis Pasteur successfully demolish the popular theory of spontaneous generation?

What way the advent of the birth-control pill have resulted in an increase in STDs?

Rohan saw Mr. Sharma collecting different plant specimens. He was confused to see him doing this collection and approached him asking about it.
Mr. Sharma told him that he will cross different plant specimens in his laboratory for obtaining better varieties of plants.

1. Why is he interested in such experiments?
2. Name this technique.
3. What precautions he should take while applying this technique?
4. What values are shown by Rohan?

Why is molecular diagnosis preferred over conventional methods? Name any two techniques giving one use of each.

Study the graph given below and answer the questions that follows.

1. Write the status of food and space in the curves A and B.
2. In the absence of predators, which one of the two curves would appropriately depict the prey population?
3. Time has been shown on X-axis and there is a parallel dotted line above it. Give the significance of this dotted line.

Draw a schematic sketch of pBR 322 plasmid and label the following in it:

1. Any two restriction sites.
2. Ori and rop genes.
3. An antibiotic resistant gene.

Explain the increase in the numbers of melanic (dark winged) moths in the urban areas of post-industrialisation period in England.

What are selectable markers? Give examples.