Human Reproduction — BIOLOGY STD 12 Science — Question

What would happen if our intestine harbours microbial flora exactly similar to that found in the rumen of cattle?

How are fishes helpful in controlling diseases? Give some examples.

Give reasons : Malignant tumour is more dangerous than benign tumour.

Corpus luteum in pregnancy has a long life. However, if fertilisation does not take place it remains active only for 10 – 12 days. Why?

Estuarine waters, Taiga, Aquarium tank, Lake, Evergreen forest, Flower garden.

Types of ecosystems	Examples
(1) Aquatic	________________
(2) Terrestrial	________________
(3) Artificial	________________

State the functions of primary and secondary lymphoid organs in humans.

You have chosen a plasmid as vector for cloning your gene. However this vector plasmid lacks a selectable marker. How would it affect your experiment?

Demand for mushroom as food has led to its culturing on a large scale. Similarly, it is perceived that microbes too would become acceptable as food. Identify a microbe which can be cultured as a food source and give the applicability of its culture in the given context.