Question

Describe how the various types of protozoans move, and give an example of each type.

What type of algae are believed to be closely related to the first plants? Why?

How might diseases like malaria, which are transmitted via mosquitoes, be affected by global warming?

Explain the difference between pollination and fertilization in plants.

What features are seen in angiosperms that are not seen in gymnosperms? How do they contribute to the success of angiosperms?

Which plant group provides the world’s major food crops of wheat, rice, and corn?

Answer 1

Ans. (i) Protozoans exhibit diverse modes of locomotion across the various groups, but the modes of locomotion can be broadly divided into following types :-

1) flagellar movement:- e.g., euglena

2) Ciliary movement :- e.g., Paramecium

3) Amoeboid movement :- e.g., amoeba

Ans. (ii) It is believed that land plants are most closely related to the green algae, more specifically, a group of green algae referred to as the charophyceans. Both land plants and green algae produce chlorophyll a and b.

Charophytes are special because they share a few important traits with land plants.

Ans.(iii) At lower altitudes where malaria is already a problem, warmer temperatures will alter the growth cycle of the parasite in mosquito enabling it to develop faster, increasing transmission and thus having implications on the burden of disease.

Ans. (iv) Pollination occurs when pollen grains from the anther land on a stigma.

Fertilization occurs when one of the sperm cells fuses with the egg inside of an ovule. After fertilization occurs, each ovule develops into a seed.

Ans.(v) Angiosperms, also called flowering plants, have seeds that are enclosed within an ovary (usually a fruit) , while gymnosperms have no flowers or fruits, and have unenclosed or naked seeds on the surface of the scales or leaves.

Angiosperms (flowering plants) are able to survive in a greater variety of habitats than gymnosperms. Flowering plants mature more quickly than gymnosperms, and produce greater number of seeds.

Ans. (vi) Cereals include wheat, rice,corn, barley, oats