Organisms and Populations — BIOLOGY STD 12 Science — Question

Explain co-dominance in humans with the help of example.

How does the HIV breakdown the immune system of the AIDS patient?

“Snow leopards are not found in Kerala forests and tuna fish are rarely found beyond tropical latitude in the ocean”. Study the above two cases and state the possible reasons for the same.

Name the five key tools for accomplishing the tasks of recombinant DNA technology. Also mention the functions of each tool.

When a foreign DNA is introduced into an organism, how is it maintained in the host and how is it transferred to the progeny of the organism?

What is self-incompatibility? Why does self-pollination not lead to seed formation in self-incompatible species?

Construct an age pyramid which reflects an expanding growth status of human population.

Certain molecular processes are given in column (A). Provide the terms given to these processes in column (B), after selecting them from the terms:
Recombination, gene regulation, prokaryotic transcription, eukaryotic transcription, translation, replication, gene transfer, DNA fingerprinting

S.No.	Column A	Column B
(i)	DNA → DNA
(ii)	DNA → hRNA
(iii)	mRNA → Protein
(iv)	Repressor Protein + Operator → No  transcription

Mention four significant services that a healthy forest ecosystem provide.