A very small population of a species faces a greater thread of extinction than a larger population. Provide a suitable genetic explanation.

When a population is small, there is a greater chance of:

Plant species having a wide range of genetical distribution evolve into a local population know as

Assertion :Species with low genetic variability are generally at greater risk of extinction than the species with more genetic variability. Reason: Species with low genetic variability are more vulnerable to disease, predators or other environmental challenges.

Assertion : Over-exploitation of a species reduces the size of its population eventually leading to its extinction. Reason : Steller's sea cow is a large, herbivorous, terrestrial mammal which is on the verge of extinction due to over exploitation. (a) If both assertion and reason are true and reason is the correct explanation of assertion. (b) If both assertion and reason are true but reason is not the correct explanation of assertion. (c) If assertion is true but reason is false. (d) If both assertion and reason are false.

Assertion : The Nile perch introduced into lake Victoria in east Africa led to the extinction of an ecologically unique assemblage of more than 200 species of cichlid fish in the lake. Reason : When alien species are introduced deliberately for economic or other uses, they often become invasive and cause extinction of indigenous species. (a) If both assertion and reason are true and reason is the correct explanation of assertion. (b) If both assertion and reason are true but reason is not the correct explanation of assertion. (c) If assertion is true but reason is false. (d) If both assertion and reason are false.

Assertion : Critically endangered category includes the species which have sufficient populationa at present but is undergoing depletion due to some factors. Reason : Vulnerable category includes the species which are facing very high risk of extinction in the wild an can become extinct any moment. (a) If both assertion and reason are true and reason is the correct explanation of assertion. (b) If both assertion and reason are true but reason is not the correct explanation of assertion. (c) If assertion is true but reason is false. (d) If both assertion and reason are false.

Which of the following statements describe natural extinction ? (i) Extinctions abetted by human activities (ii) Slow replacement of existing species (iii) Also known as background extinction (iv) A small population is most likely to be extinct (a) (i) and (ii) (b) (i), (ii) and (iii) (c) (ii), (iii) and (iv) (d) (i), (ii), (iii) and (iv)

Where would the greatest number of endemic species occur and why ? (a) Small volcanic archipelagos, such as the Galapagos Islands, because the abundance of unoccupied habitats favours the adaptive divergence of colonists from nearby mainland populations. (b) Large oceanic island, such as Australia, because the inhabitants have been isolated from mainland populations for a very long time. (c) On rugged landscapes, such as Patagonia, because of the high levels of natural disturbance by glaciers and earthquakes. (d) Temperate woodlands, such as those in southern England, because of the high levels of disturbance by human activity and the history of artificial selection.

Some so called doctors claim that their medicines provide 100% guarantee for getting a son or a daughter according to the wish of the parent. How do you react to such claims on the basis of your knowledge of genetics? Give a suitable explanation.

Assertion : Broadly utilitarian arguments say that we should conserve biodiversity because biodiversity plays a major role in many ecosystem services that nature provides. Reason : Expolration of molecular, genetic and species level diversity to obtain the products of economic importance is include under broadly utilitarian category. (a) If both assertion and reason are true and reason is the correct explanation of assertion. (b) If both assertion and reason are true but reason is not the correct explanation of assertion. (c) If assertion is true but reason is false. (d) If both assertion and reason are false.