What is true about the isolated small tribal populations? 

• There is a decline in population as boys marry girls only from their own tribe

• Hereditary diseases like colour blindness do not spread in the isolated population

• Wrestlers who develop strong body muscles in their lifetime pass this character on their progeny

• Wrestlers who develop strong body muscles in their lifetime pass this character on their progeny

Consider the following statements concerning food chains

A) removal of 80% tigers from an area resulted in greatly increased growth of vegetation

B) removal of most of the carnivores resulted in an increased population of deers

C) length of food chains is generally limited to 3-4 trophic levels due to energy loss

D) the length of food chains may vary from 2 to 8 trophic level

Which two of the above statements are correct? 

• B and C

• C and D

• A and D

• A and D

The population of an insect species shows an explosive increase in numbers during rainy season followed by its disappearance at the end of the season. What does this show?

• S-shaped or sigmoid growth of this insect

• The food plants mature and die at the end of the rainy season

• Its population growth curve is of J-type

• Its population growth curve is of J-type

Geometric representation  of age structure is a characteristic of

• Biotic community

• Population

• Landscape

• Landscape

Select the correct statement from the following:

• Darwinian variations are small and directionless

• Fitness is the end result of the ability to adapt and gets selected by nature

• All mammals except whales and camels have seven cervical vertebrae

• All mammals except whales and camels have seven cervical vertebrae

Two plants can be conclusively said to belong to the same species if they

• can reproduce freely with each other and form seeds

• have more than 90 per cent similar genes

• look similar and possess identical secondary metabolites

• look similar and possess identical secondary metabolites

Probiotics are

• safe antibiotics

• cancer inducing microbes

• new kind of food allergens

• new kind of food allergens

Which one of the following pairs of organisms are exotic species introduced in India?

• ficus religiosa , lantana camara

• lantana camara, water hyacinth

• water hyacinth, prosopis cinereria

• water hyacinth, prosopis cinereria

The living organisms can be unexceptionally distinguished from the non-living things on the basis of their ability for

• responsiveness to touch

• interaction with the environment and progressive evolution

• reproduction

• reproduction

If the mean and the median pertaining to a certain character of a population are of the same value, which of the following is most likely to occur

• a normal distribution

• a bi-modal distribution

• a T-shaped curve

• a T-shaped curve