Principles of Inheritance and Variation — BIOLOGY STD 12 Science — Question

How does haemozoin affect the human body when released in blood during malarial infection?

Name the two factors that cause the formation of major biomes.

What general term is given to the method in which the male partner withdraws his penis from the vagina just before ejaculation so as to avoid insemination?

In the given population growth curve.

1. What is the status of food and space in the curves (a) and (b)?
2. In the absence of the predators, which curve (a) or (b) would appropriately depict the prey population?

What does 'Red' indicate in the IUCN Red list (2004)?

What is stratification in an ecosystem? Explain with an example.

The microscopic pollen grains of the past are obtained as fossils. Mention the characteristic of the pollen grains that makes it happen.

If the base adenine constitutes 30 percent of an isolated DNA fragment, then what is the expected percentage of the base cytosine in it?

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: Organs of pig such as heart, pancreas, etc., for human use can be grown through transgenic animals.
Reason: Transgenic pigs show improved growth and meat production.

Name any two barriers used by human females for birth control.