Organisms and population practice · Mixed difficulty

Conformers are inactive in adverse conditions due to

The maintenance of internal favourable conditions, by a self regulated mechanism inspite of the fact that there are changes in environment, is known as:

Human liverfluke (a trematode parasite) depends on which two intermediate hosts I. Snail II. Fish III. Pig IV. Mosquito Choose the correct combination

Ecology is basically concerned with how many levels?

Behavioural adaptation to environment in desert lizards are
I. Burrowing soil
II. Losing heat during high temperature
III. Active during morning and evening
IV. Insulating body due to thick fatty dermis
Select the correct pair

Which of the following is an example of a defence used by plants against herbivores?
I. Production of caffeine, tannin quinine
II. More production of non-woody tissues
III. Productions of hairs, thorns, spines
IV. Production of hormone-like chemicals that interfere with insect metamorphosis
Select the correct pair

Assertion: It drains off oxygen from water and
is seen growing in standing water with respect
to Eichorrnia.

Reason: It is an indigenous species of our
country.

During encystations, Amoeba withdraws its pseudopodia and secretes a ……… layered hard covering or cyst around itself.

If ‘8’ Drosophila in a laboratory population of ‘80’ died during a week, the death rate in the population is ___________ individuals per Drosophila per week.

…A… regulators are able to maintain homeostasis by means which ensures constant body temperature, constant osmotic concentration, etc. All …B… and …C…. and is very few lower vertebrate and invertebrate species are indeed capable of such regulation (thermoregulation and osmoregulation)
Evolutionary biologists believe that the ‘success’ of mammals is largely due to their ability to maintain a constant body …D… and thrive whether they live in Antarctica or in the Sahara desert
Choose the correct option for A, B, C and D

Diapause is

Root cap is not found in

Partial regulators are the organism which

Ecotone is

Which one of the following plants is an invasive
species that has spread to many parts of the
Indian subcontinent?

Casuarina equisetifolia is which one of the following.

Introduced plants in new localities must show adaptations called

Population is said to be mature or stable, when

Within biological communities, some species are important in determining the ability of a large number of other species to persist in the community. Such species are called:

Ecosystem components includes

Assertion: Daphnia populations in a water
body, at different seasons of a year showed
marked variations in their body morphology.

Reason: Cyclomorphosis in some organisms is
influenced by the variations in temperatures
prevailing in their water-bodies at different
seasons.

Niche overlap indicates

[A]: Many desert mammals cool the exhaled air in their noses, before it is expelled out through nostrils.

[R]: The moisture condenses in the nose and is not lost as water vapours along with the exhaled air.

What are the symptoms of altitude sickness?

Assertion: True xerophytes do not store water
in the form of mucilage which helps to withstand
prolonged period of drought.

Reason: Vascular and mechanical tissues are
well developed in true xerophytes.

Assertion : Sometimes one population
adversely affects the other by direct attack but
yet depends upon them.

Reason : In predation the contact is instant.

Light is

Choose the wrong statements
I. Two species may not live in same habitat
II. The more dissimilar the niches of two species the stronger is their competition
III. Two species can occupy the same niche in geographical area
IV. No two species may occupy the same ecosystem
The correct option is