Biogenetic law was putforward by
E. Haeckel
Charles Darwins
Karl von Bear
Lamarck
Ephemerals are xerophytes that are
The apex of age pyramid of a stationary population is
Find out the population density when $N$ is $1000$ and $S$ is $100\, m ^{2}$
Crop rotation is helpful because
The equilibrium of the species is disturbed by