Reproduction in organisms — BIOLOGY STD 12 Science — Question

Draw a schematic transverse section of a mature anther of an angiosperm. Label its epidermis, middle layers, tapetum, endothecium, sporogenous tissue and the connective.

The base sequence on one of the strands of DNA is ATGTCTATA.

1. Give the base sequence of its complementary strand.
2. If an RNA strand is transcribed by this strand, what would be the base sequence of RNA?
3. In what other respect, an RNA molecule differs from a DNA molecule?

GM Plants are useful in many ways. How would you convince the farmers to grow GM plants in their fields? Explain giving three reasons.
OR
People are quite apprehensive to use GM crops. Give three arguments in support of GM crops so as to convince the people in favour of such crops.

Narrowly utilitarian arguments are put forth in support of biodiversity conservation. Explain the other two arguments that are put forth in support of the same cause.

Name any three types of postmating isolating mechanisms.

Explain the various steps involved in the production of artificial insulin.

Microbes have various contributions to the human welfare. For example, lactic acid bacteria help in checking disease causing microbes in our stomach. With reference to this fact, state the contribution of different microbes in the process of digestion in ruminants.

What are transgenic plants? Explain with any two examples.

Give scientific : We are advised to use iodized salt.### Why do we use iodized salt?