Reproduction in Lower and Higher Animals — BIOLOGY STD 12 Science — Question

1. In a human genome, which one of the chromosomes has the most genes and which one has the fewest?
2. Scientists have identified about 1.4 million single nucleotide polymorphs in human genome. How is the information of their existence going to help the scientists?

Identify a, b, c, d, e and f in the table given below:

	Organism	Bioactive molecule	Use
1. 2. 3.	Monascus perpureus (yeast) c e	a d Cyclosporin A	b antibiotic f

What are bacteriophage vectors? Name the two phage vectors that are commonly used.

Give the scientific name of the parasite that causes malignant malaria in humans. At what stage does this parasite enter the human body? Trace its life cycle in human body.

How can a bioreactor be made to function at optimal state in order to obtain a desired foreign gene product? Explain.

Are parthenocarpy and apomixis different phenomena? Discuss their benefits.
Hint: Yes, they are different. Parthenocarpy leads to development of seedless fruits. Apomixis leads to embryo development.

What is tissue culture? Describe the methodology of tissue culture.

Why should the spraying of DDT as an insecticide on vegetable crops be banned? Explain.

Explain out-breeding, out-crossing and cross-breeding practices in animal husbandry.

Enlist the meninges of human brain.