Question

7. For angiosperms, describe the relationship between the sporophyte and gametophyte in terms of nutritional dependence and size.

a. Is the gametophyte dependent on the sporophyte at any time during the life cycle? If so, explain how.

b. Is the sporophyte dependent on the gametophyte at any time during the life cycle? Explain your answer.

c. Compare the relationship between the gametophyte and sporophyte in seedless plants and angiosperms. How does the relationship differ?

d. Can you think of any advantages to the relataionship in angiosperms?

Answer 1

a. yes gametophyte is dependent on sporophyte, during formation of reproductive structure and fully dependent on sporophyte. All the reproductive structures like Flower, anther and stigma are attached to the sporophyte and small in size. 7 celled structure embryo sac inside ovary is the gametophyte of angiosperm.

b. No, sporophyte produced from the seed, it never depends on the gametophyte for nutrient, and its size is very large compared to gametophyte.

c. In seedless plant (thallophyte, bryophyte, and pteridophyte) in thallophyte and bryophyte, the gametophyte is dominant over sporophyte. size os bigger and also exist for a longer time, sporophyte depends on gametophyte for nutrition.

in pteridophyte both are independent. same contribution in the life cycle.

But in case of angiosperm and gymnosperm, the sporophyte is dominant on gametophyte, size of sporophyte is big, lifetime is longer and independent for nutrition, the gametophyte is short-lived, dependent on sporophyte for nutrition.

d. yes, the sporophytic part can be independent, long-lived, perennial, so less chance of extinction, secondary growth, as a result, forms wood/timber.