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

139.

A high density of elephant population in an area can result in

• Mutualism

• Intraspecific competition

• Interspecific competition

• Interspecific competition

How does pruning help in making the hedge dense?

• It induces the differentiation of new shoots from the rootstock

• It frees axillary buds from apical dominance

• The apical shoot grows faster after pruning

• The apical shoot grows faster after pruning