Human Reproduction — BIOLOGY STD 12 Science — Question

Double fertilisation is reported in plants of both, castor and groundnut. However, the mature seeds of groundnut are non-albuminous and castor are albuminous. Explain the post-fertilisation events that are responsible for it.

Explain the Hardy-Weinberg equilibrium principle.

Why is that once a person starts taking alcohol or drugs, it is difficult to get rid of this habit? Discuss it with your teacher.

Study the given pedigree chart and answer the questions that follow.

1. Is the trait recessive or dominant?
2. Is the trait sex linked or autosomal?
3. Give the genotypes of the parents shown in generation I and their III child shown in generation II and the first grandchild shown in generation III.

How can Hardy-Weinberg equilibrium be affected? Explain giving three reasons.

Where is an 'operator' located in a prokaryote DNA? How does an operator regulate gene expression at transcriptional level in a prokaryote? Explain.

What is apomixis and what is its importance?

Identify by giving reasons, the salient features of genetic code by studying the following nucleotide sequence of mRNA strand and the polypeptide translated from it.
(AUG UUU UCU UUU UUU UCU UAG) (Met - Phe - Ser - Phe - Phe - Ser)

Consult internet and find out how to make orally active protein pharmaceutical. What is the major problem to be encountered?

The following graph AE represents the organismic response to certain environmental condition (e.g. temperature)

1. Which one among A and B depicts conformers?
2. What does the other line graph depict?
3. How do these organisms differ from each other with reference to homeostasis?
4. Mention the category to which humans belong. Internal level.