Try to collect all the currently accepted meanings for the word ‘species’. Discuss with your teacher the meaning of species in case of higher plants and animals on one hand and bacteria on the other hand.

A radioactive sample consists of two distinct species having equal number of atoms initially. The mean life of one species is tau and that of the other is 5 tau . The decay products in both cases are stable. A plot is made of the total number of radioactive nuclei as a function of time. Which of the following figure best represents the form of this plot? (a), (b), (c), (d)

Autogamy means (A) pollination of a flower by its own pollen (B) pollination of a flower by different of same species (C) pollination of a flower by different pollen of different species (D) Pollen of a flower pollinate any other flower present on same plant