Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions

In a pond, we see plants which are free-floating; rooted–submerged; rooted emergent; rooted with floating leaves; Write the type of plant against the following examples.

In an association of two animal species, one is a termite which feeds on wood and the other is a protozoan Trichonympha present in the gut of the termite. What type of association they establish?

Lianas are vascular plants rooted in the ground and maintain erectness of their stem by making use of other trees for support. They do not maintain direct relation with those trees. Discuss the type of association the lianas have with the trees.

Give one example for the following type.

Camouflaged animal

Give one example for the following type.

Predator animal

Give one example for the following type.

Biological control agent

Give one example for the following type.

Phytophagous animal

Give one example for the following type.

Chemical defense agent

Fill in the blanks

Observe the set of 4 figures A, B, C and D and, answer the following questions

1. Which one of the figures shows mutualism?
2. What kind of association is shown in D?
3. Name the organisms and the association in C.
4. What role is the insect performing in B?

Fig. (A)	Fig. (B)
Fig. (C)	Fig. (D)

Discuss the various types of positive interactions between species.

In an aquarium two herbivorous species of fish are living together and feeding on phytoplanktons. As per the Gause’s Principle, one of the species is to be eliminated in due course of time, but both are surviving well in the aquarium. Give possible reasons.

While living in and on the host species, the animal parasite has evolved certain adaptations. Describe these adaptations with examples.

Give one example for the following:

A parasitic angiosperm

Give one example for the following:

An organism which can conform

What is common to the techniques (i) in vitro fertilisation, (ii) Cryo preservation and (iii) tissue culture?

Define the terms bioprospecting

Define the terms endemism

How is the presently occurring species extinction different from the earlier mass extinctions?

Humans benefit from diversity of life. Give two examples.