Sexual Reproduction in Flowering Plants — BIOLOGY STD 12 Science — Question

What are the effects of nicotine?

Name the respiratory disease that infects lungs and one that do not infect lungs.

Name the type of cross that would help to find the genotype of a pea plant bearing violet flowers.

What is the total number of hot spots in the world? How many of them are there in India?

A mother of one year old daughter wanted to space her second child. TO SIO boni Her doctor suggested CuT. Explain its contraceptive actions.

The following statements (i), (ii) and (iii) seem to describe the water-pollinated submerged plants. Which one of these statements is incorrect?

1. The flowers do not produce nectar.
2. The pollen grains have mucilaginous covering.
3. The brightly-coloured female flowers have long stalks to reach the surface.

Who was considered the sub-human and the primitive man?

How is the first sign of growing foetus noticed?

What are true-breeding lines that are used to study inheritance pattern of traits in plants?

Read the following four statements (A-D) about certain mistakes in two of them.

1. The first transgenic buffalo, Rosie pro- duced milk which was human alpha-lac- talbumin enriched.
2. Restriction enzymes are used in isolation of DNA from other macro molecules.
3. Downstream processing is one of the steps of R-DNA technology.
4. Disarmed pathogen vectors are also used in transfer of R-DNA into the host.

Which are the two statements having mis- takes?

1. Statements (A) and (B)
2. Statements (B) and (C)
3. Statements (C) and (D)
4. Statements (A) and (C)