Reproductive Health — BIOLOGY STD 12 Science — Question

In a pond, there were 200 frogs. 40 more were born in a year. Calculate the birth rate of the population of frogs in the pond.

Mention the pollinating agent of an inflorescence of small dull-coloured flowers with well exposed stamens and large feathery stigmas. Give any one characteristic of pollen grains produced by such flowers.

Group the following as nitrogenous base and nucleosides :
Adenine, Cytidine, Thymine, Guanosine, Uracil and Cytosine.

Define : Community

State the function of filiform apparatus found in mature embryo sac of an angiosperm.

Give an example where animal-plant interaction involves co-evolution.

What do you mean by the term 'alien species'?

Define mortality.

Give an example of a plant which came into India as a contaminant and is a cause of pollen allergy.

A Volcano erupted in Hawaii, and lava covered land that had been framed for centuries. Eventually, new lichens, and then plants, grew on the lava. Is this an example of primary or secondary successions? Give the reason also.