Ecosystems — BIOLOGY STD 12 Science — Question

Which species of Penicillium produces Roquefort cheese?

How are the distances of stars measured?

State one reason why breast feeding the baby acts as a natural contraceptive, for the mother?

What is the linkage between nitrogenous base and pentose sugar called?

How does colostrum provide Initial proteitton agannt diseases to newborn infants? Give one reason.

Why is sharing of injection needles between two individuals not recommended?

CryIAb is introduced in a plant to control infestation by corn borer.

1. Name the resultant plant after successful insertion of the gene desired.
2. Summarise the action of the gene introduced.

Answer the following questions:
Colonisation of a rocky terrain is a natural process. Mention the group of organisms which invade this area first. Give an example.

In a dihybird, cross, when would the proportion of parental gene combinations be much higher than non-parental types, as experimentally shown by Morgan and his group?

Aquatic animals that change the osmotic concentration of their body fluids according to the environment are known by which name?