What are the pros and cons of sexual and asexual reproduction

Asexual reproduction requires one parent and produce biologically identical offspring

While sexual reproduction requires two parent and produce biologically varied offspring

Explanation:

The advantage of asexual reproduction is that it requires only one plant and the rate of production of offspring is very high.

Disadvantage of asexual reproduction - limited competition among the species and hence more burden on the existing resources. No genetic variation.

Advantage of Sexual reproduction - Natural selection process causes genetic variation due to which only the fittest species survive thereby putting less burden on the ecosystem.

Disadvantage of sexual reproduction - Requirement of two parents

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.