Diffusion allows the exchange of substances; the entry of oxygen, proteins, etc into the cell and the removal of waste substances.
Answer:
'Cross experiments done by Morgan, illustrating the X-inheritance link of a mutation Thomas Hunt Morgan moved intensely in a program of breeding and crossing miles of fruit flies at New York University in a room that was renamed the Fourth of the Flies. He tried to mutate the flies with various means (X-rays, centrifuges, etc.) .The fruit fly which has 4 pairs of chromosomes. One of those pairs was identified as containing X and Y sex chromosomes. He applied Mendelian principles in flies. Morgan's inheritance study demonstrated inheritance linked to sex, and is one of the first evidences that confirm the chromosomal theory of cross-based inheritance. In 1909, Morgan detected a fruit fly (Drosophila melanogaster) with a strange mutation which he called "white eyes", due to the coloration of his eyes (contrary to normal, which is red). Analyzing this fly under the microscope Morgan discovered that it was a male, and could use it as a stallion so that he could observe how the new characteristic of white eyes would pass from generation to generation.All the offspring of this cross will have red eyes, which He made Morgan suspect that something strange had happened, since the color of the father's eyes could not have disappeared. He decided to take a couple of "daughters flies" and cross them together, just to see what happened. Morgan's surprise was very great, observing that among the "granddaughters" flies only males had white eyes. The problem then was to explain what had happened during the hereditary transmission for the color of the white eyes only the males possessed. .
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.
