Reproductive Health — BIOLOGY STD 12 Science — Question

Write the physiological reason, why a woman generally cannot conceive a child after 50 years of age.

1. Draw a labelled sketch of a mature 7-celled, 8-nucleate embryo-sac.
2. Which one of the cell in an embryo-sac produce endosperm after double fertilisation?

Draw a labelled sketch of sparged-stirred tank bioreactor. Write its application.

A 250kg cow produces 200g of protein per day but 250g of Methylophillus methylotrophus can produce 25 tonnes of protein Name this emerging area of research. Explain its benefits.

1. Name the respective forms in which the malarial parasite gains entry into

1. Human body
2. Body of female Anopheles

2. Name the hosts where the sexual and the asexual reproductions of malarial parasite occur respectively.
3. Name the toxin responsible for the appearance of symptoms of malaria in humans. Why do these symptoms occur periodically?

Mention three uses of PCR.

Give any six features of the human genome.

Draw a schematic diagram of the E.coli vector PBR 322 and mark the following in it:

1. Ori
2. Rop
3. Ampicillin-resistant gene
4. Tetracycline-resistant gene
5. Restriction site BamHI
6. Restriction site EcoRI

1. Draw a diagram of pistil showing pollen tube growth in angiosperm and label;

1. Stigma.
2. Male gametes.
3. Micropyle.
4. Ovule.

2. Write the function of micropyle.

What is the fate of trophoblast in mammalian embryo?