Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Cucurbits and papaya plants bear staminate and pistillate flowers. Mention the categories they are put under separately on the basis of the type of flowers they bear.
OR
How are Cucurbita plants different from papaya plants with reference to the flowers they bear?

1. Sickle celled anaemia in humans is a result of point mutation. Explain.
2. Write the genotypes of both the parents who have produced a sickle celled anaemic offspring.

1. Draw a neat labelled diagram of a nucleosome.
2. Mention what enables histones to acquire a positive charge.

What is the mode of action of heroin in the body?

How do 'implants' act as an effective method of contraception in human females? Mention it's one advantage over contraceptive pills.

In a population which has achieved Hardy-Weinberg equilibrium, which two process will not occur.

Identify the statements as correct/ incorrect and give proper justification for your answer.

1. Zygote is the link between two generations.
2. Zygote is a single cell.
3. In organisms with haplontic life cycle, zygote divides by meiosis to form haploid spores.
4. In organisms with haplontic life cycle, zygote divides by mitosis to form haploid spores.

Lantana and Eichhornia are examples of two weeds. How do they affect the ecosystem?

Write full form of ELISA. Give an example of the clinical application of ELISA test.

Give a scientific term for the following sentences:

1. Total number of individuals of a species in an area.
2. A surgical procedure performed on males in which the vas deferens are cut and tied is known as:
3. A contraceptive device consisting of a small thimble-shaped cup that is placed over the uterus to prevent the entrance of spermatozoa.
4. Removal of gonads, often referring to the removal of male testes is called.