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

Name the type of barrier of innate immune system, which involves:

1. HCl of stomach
2. Macrophages.

Explain why very small animals are rarely found in polar region.

What is meant by gene therapy?

Name the blank spaces A, B, C and D in the table given below:

Name of the drug	plant source	Organ system affected
A	Poppy plant	B
Marijuana	C	D

What is cleavage?

Demand for mushroom as food has led to its culturing on a large scale. Similarly, it is perceived that microbes too would become acceptable as food. Identify a microbe which can be cultured as a food source and give the applicability of its culture in the given context.

Explain giving three reasons why tropics show, greatest level of species diversity.

If a double stranded DNA has 20% of cytosine, calculate the per cent of adenine in the DNA.

DNA is unzipped twice in a cell. Mention the two events and the enzymes responsible for it.

When mammals took over the earth write the character and continental drift of the mammals of that time?