Advantage: Dichotomous keys are very useful because they allow non-expert users to identify organisms by directing them to look at the known, important organisms. Disadvantage: Disadvantage of dichotomous keys is that if a single wrong decision is made at any juncture, a wrong identification will result. Sometimes it becomes obvious that an error has been made, and you can retrace your steps until you get back on the right track, but this is not always the case
Answer:
Natural selection
Explanation:
Sexual selection refers to the natural selection where the allele frequencies of a population are changed due to nonrandom mating between the individuals. Certain preferences for the mate by organisms result in sexual selection. It is mostly exhibited by females.
For example, peahen prefers the peacocks with elaborate tail features as their mate. The sexual selection also occurs when there is competition among the members of the same sex for a mate. This type of sexual selection is mostly exhibited by males and results in fighting and display.
I am Guessing Sperm and egg