Reproduction in organisms — BIOLOGY STD 12 Science — Question

Colostrum contains antibody IgA and provides passive immunity.[True/ False]

Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion: Genetically modified microbes help in crop protection.
Reason: Transgenic bacteria control insects by producing endotoxins.

Embryo sac Nucellus → Integuments, is the correct sequence of parts in the ovule of an angiosperms.

Explants are the dead plants.

Match the terms in Column I with those in Column II.

	Column I		Column II
A	Amensalism	1	The interspecific interaction, where both are equally benefitted.
B	Parasitism	2	The interspecific interaction, where one is benefitted and one is neutral.
C	Mutualism	3	The interspecific interaction, where one is harmed and the other is neutral.
D	Commensalism	4	The interspecific interaction, where one is benefitted and one is harmed.
E	Competition	5

Relaxin is the hormone secreted by the placenta.

Identify True/ False statements. Correct each false statement to make it true.
Androgens are produced by Sertoli cells. (True/ False)

In an ecological pyramid, the amount of energy available at the lower trophic level is always more than that at a higher trophic level.

The pioneer species always remain in equilibrium with the environment and do not change easily.

Which of the following principle is associated with the ethics of animal use in genetic engineering?

1. Reduction of animal use
2. Refinement of husbandry
3. Replacement of animal with non-animal alternatives
4. All of the above