Question

Biodiversity is determined by
(a) Number of individuals in an area.
(b) Species richness
(c) Evenness
(d) Both (b) and (c)

Answer 1

This is expressed as the number of species and also another one is related to the proportions of species or functional groups present on a site.

Correct answer:
Biodiversity is determined by richness and Evenness of the species. The variety and variability found among all living organisms present within a given ecological area is known as biodiversity. The term biodiversity also includes the number of species, the diversity in their genetics or variation in their habitat which is also referred to as ecological variations.The richness and evenness of species are the two main components that contribute to biodiversity.

Additional Information:
-The number of different species present in an area describes the richness of species. This means more the number of species, greater will be the richness.
-The relative abundance of the different species in a particular area describes the evenness of species. This means as much as the similar abundance, more will be the evenness of species.
-The relative biodiversity of a given community can be measured by the simpson’s reciprocal index.
-To measure the biodiversity the Simpson's reciprocal index considers both; the number of species present that means richness and the number of individuals per species that means evenness.
-A greater degree of biodiversity within the community is indicated by a higher index value.
-Number of individuals living in an area is referred to as the population of that area.
-Generally at hotspots the biodiversity tends to cluster and through time it increases also but in future it slows down as the result of deforestation.

So, the correct answer is,'Both (b) and (c)

Note:
-According to scientists there are approximately 8.7 million species of plants and animals on earth.
-Hotspots are those areas which bear extremely high levels of biodiversity.
-With the help of simpson’s reciprocal index different communities are compared to identifying their intrinsic qualities.