Are my answers correct?
Please explain why/why not.
QUESTION 2:
Depending upon the stage in which meiosis occurs; three principal types of botanical life cycles were illustrated as being utilized by Green Algae for the purposes of sexual reproduction. One of these life cycles is a significant evolutionary step on the road to more advanced reproduction in land plants.
This life cycle may be given as three terms. Name all three.
Haplontic
mitosis occurs only in haploid cell
gametes produced through mitosis
haploid unicellular or multicellular organisms can be formed.
Diplontic
mitotic division occurs only in diploid cell
In the haploid phase during meiosis, only gametes are formed.
Haplodiplontic
mitosis occurs in both haploid and diploid cell.
In this cycle cells go through both type of phases i.e Sporophyte and gametophyte and is called alteration of generation
Which is more dominant in this life cycle, the diploid (2n) or the haploid phase (n)?
For Algae, haploid phase (n) is more dominant in this life cycle then the diploid phase (2n).
What are the names of the two different generations?
Gametophyte and sporophyte are the names of the two different generations.
Gametophyte produce gametes or “sex cells,” while Sporophyte are asexual and produce spores – sporophyte generation.
Why is the primitive version of said life cycle termed isomorphic?
Diplohaplontic is this primitive version termed as isomorphic, because both the gametophyte and sporophyte generations look morphologically similar, i.e., they are isomorphic to each other.
What is the divisional product of each generation? (2 marks)
The divisional product of the gametophyte generation is gametes (n) which are haploid, while that of the sporophyte generation is spores (n) which are diploid.
Gametophyte generation produces haploid gametes,
Sporophyte generation produces diploid zygote.
What is the evolutionary significance of this life cycle? Give five short points.
The haploid phase allows for easy dispersal and adaptation to changing environments.
The alternation of generations facilitates genetic exchange and adaptation.
The evolution of this life cycle paved the way for the development of more complex life cycles in higher plants.
The production of spores and gametes allows for the formation of resistant structures and the spread of genetic material.
The haplodiplontic cycle allows for both sexual and asexual reproduction.