Question

The interbreeding individuals of a species showing continuous distribution are
A. Endemic
B. Deme
C. Cline
D. Ecotones

Answer 1

Hint: In a continuous distribution, interbreeding between individuals of a species leads to a random exchange of genes. Ecotone, cline, and endemic are a term used in Ecology which does not relate to inter-breeding individuals.

Complete answer: Endemic: It is a term used widely in various subjects. In bio-geographical studies, endemic has used an adjective to mean that a particular species, genus, or other taxon is naturally found in, or native to, or confined within a particular geographical area or population.

Deme: It is a term used in ecological studies. It refers to a population within which the exchange of genes occurs randomly. In a deme, all mating combinations between individuals of opposite sexes can occur with the same probability.
Cline: It is also a term used in ecology which means the gradual change in both the phenotypes and genotypes of individuals of a taxon across a geographical gradient, especially when they are distributed in a large geographical area.
Ecotone: It is a transitional area between two different types of vegetation, e.g. area between forest and grassland.

So, the correct answer is B. deme.

Note: In a deme, individuals can be contributed to the neighboring populations and they can also receive immigrants from them. It means that even though the individuals are interbreeding in a continuous population, migration may be allowed.