The theory proposed by Hugo de Vries is called .......

The frequency of a mutant gene in a population is expected to increase if the gene is ......

What is the reason that some bacteria can grow in a medium containing streptomycin?

The phrase 'Survival of the Fittest' was used by

Darwinian fitness refers to .........

Hybrid breakdown refers to the condition where the $F_2$ generation or subsequent generations of a hybrid cross are physiologically inferior or less viable compared to the $F_1$ generation.