Explanation:
Psi packaging Element is a cis-acting RNA element identified in the genomes of the retroviruses Human immunodeficiency virus (HIV) and Simian immunodeficiency virus (SIV) It is involved in regulating encapsidation of the retroviral RNA, an essential step in replication.
Because of underdeveloped lungs the frog has to breathe through moist skin. Therefore for exchange of gases the skin is thin and moist
The correct answer is: The recessive allele produces a phenotype that is better able to survive and reproduce than the dominant phenotype.
Natural selection (adaptation mechanism), gene flow, and mutation combine to change allele frequencies across generations. Natural selection tends to increase in frequency beneficial alleles, while it tends to decrease in frequency deleterious alleles.
The answer is <span>The flagellated sperm would not be able to swim to the eggs for fertilization.
</span><span>Their life cycle of mosses has alternation of generation -
a haploid gametophyte and a diploid sporophyte. Gametophyte produces haploid
gametes which fuse to form a diploid zygote. The zygote grows into diploid
sporophyte which produces haploid spores. The spores grow into gametophyte and
the cycle begins again.
</span>Mosses require water for reproduction. Before fertilization, the sperm swims to an egg through the water. Therefore, mosses require water for successful fertilization. In drought periods, without water, the sperm cell could not swim to the egg cell.
