Question

Beta ($\beta$) diversity refers to diversity
A. Within a community
B. Between communities
C. Between two eco zones
D. Within a population

Answer 1

Biodiversity represents the combined diversity (heterogeneity) at all the levels of biological organizations such as macromolecules within the cells, genes, species and biomes. The term biodiversity is coined by Edward Wilson.

Complete answer:
Beta diversity refers to diversity between communities.
Biodiversity are of three types:

Genetic diversity: It is defined as the variety in genetic information contained in the organism. Genetic diversity allows the population to adapt its surrounding environment and changes occurring the environment.
Species diversity: It is defined as the variety of species within a region. It is a product of species richness and species evenness.
Ecological or community diversity: It is the variety of ecosystems which indicate diversity in the number of niches, trophic levels, food webs and ecological processes.
R.H. Whittaker divided community diversity into three types:
Alpha diversity: It is defined as the average number of species in a habitat or specific area.
Beta diversity: It is the relation between alpha and regional diversity. It is the diversity between the communities.
Gamma diversity: It is the combination of both alpha and beta diversity. This diversity is the total diversity of a landscape.

So the correct answer is option B.

Note: India is rich in biodiversity because of the presence of a large number of ecosystems like deserts, rain forests, mangroves, coral reefs, wetlands, estuaries and alpine meadows. India has 17 biodiversity rich hotspots. The biodiversity is quite low in small countries.