Organisms and Populations — BIOLOGY STD 12 Science — Question

Write the main cause of loss of biodiversity.

If the sequence of the coding strand in a transcription unit is written as follows:
5'-ATGCATGCATGCATGCATGCATGCATGC-3'
Write down the sequence of m-RNA

Mark the odd one in the following group.
5S rRNA, SARNA, hnRNA, RNA.

What is meant by withdrawal symptoms?

Name the three layers of uterine wall.

Morgan et al found that even on the same chromosome, recombination between some gene pairs was higher than that between some other gene pairs. Give reason for this observation.

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.

What is polyembryony?

Give an example where animal-plant interaction involves co-evolution.

Give some reasons for infertility among young couples.