Algae are simple thalloid, chlorophyll-bearing, aquatic (both marine and freshwater) organisms. The form and size of algae is highly variable. They are categorised into three classes.
(a) Name the three classes of algae.
(b) Mention the two major characteristics that form the basis for this classification.
(c) Name one unicellular alga.

Two members of a class of algae are shown above.
(a) Identify the two algae A and B and name the class, which they both belong to.
(b) Name the pigment which gives them the characteristic colour.
(c) Mention the characteristics of their gametes with reference to
(i) shape and
(ii) flagellation.

Bryophytes are the first land plants, which occur in damp, cool and shady places. They are known as amphibians of plant kingdom, as they need water for fertilisation. In general, Bryophytes are of little economic importance; but, they are of great ecological importance.
(a) Write two ecological significance of mosses.
(b) Name the moss used for trans-shipment of living material. Justify your answer.

(a) Identify the plant given above and name the division, it belongs to.
(b) Label the parts A, B, C and D marked on it.

Gymnosperms and Angiosperms are seed-bearing plants. Yet, they are put under two different divisions of the kingdom Plantae.
Write three major differences between the two divisions regarding the reproductive structures and the process of reproduction.

In angiosperms, flowers are the specialised reproductive structures. Stamens are the male , reproductive organs, where pollen grains are produced in the anther. Carpels are the female reproductive organs that contain the ovules. The pollen grains germinate on the stigma, each producing two male gametes to fertilise an ovule.
(a) Why are two male gametes necessary to fertilise an ovule?
(b) What do the products develop into?

In plants, both haploid and diploid cells can divide by mitosis. This feature leads to the formation of haploid and diploid plant bodies/phases.
(a) What technical term is given to the haploid and diploid plant bodies/phases, respectively?
(b) Name the type of cell division involved in the formation of
(i) gametes by haploid Plant body.
(ii) spores by diploid plant body/phases.
(c) What do the spores germinate/develop into?

Since both haploid and diploid plant bodies are present in sexually reproducing plants, there is alternation of generations, i.e., between the haploid and diploid phases. The different plant groups differ in the patterns of life cycle they show.
What are the three different life cycle patterns exhibited by plants? Mention one example of a plant or a plant group for each of the three patterns.

(a) Identify the type of life cycle pattern shown in the diagram given above. Name an alga that shows this life cycle pattern.
(b) Name the types of life cycle patterns exhibited by plants with dominant diploid phase. Give an example for each.