Rhinoviruses are transmitted through the air or via contact. We might expect this sort of transmission to require a fairly healthy host (one who gets out and comes into contact with others) and, hence, to select against virulent strains. If we take precautions and try to stay away from people or avoid any contact with people, more hand-washing stations, increased attention to sanitization, and isolation of patients will help to reduce the transmission of the disease and, in the process, may favor the evolution of less virulent strains of the virus.
Answer:
This question lacks options; the options are:
A) Artificial selection
B) Stabilizing selection
C) Disruptive selection
D) Directional selection
The answer is D) Directional selection
Explanation:
Changes in the environmenal condition affects the distribution of organisms phenotypes. Via this change, organisms with certain traits are naturally selected. The types of natural selection are; stabilizing, disruptive and directional.
Based on the description of the selection in this question, the type of selection is DIRECTIONAL. Directional mutation is that in which one of the two extreme phenotypes in a population is selected against while the other is favored by the occurrence of a natural environmental hazard. The distribution gradually shifts to favour one extreme over the other until the other unselected extreme gets extincted.
This is the case regarding a population of finches affected by drought caused by flood causing all their food source to disappear leaving only ant hills that certain finches with thin beaks can access. This environmental change favorably selects one extreme phenotype (finches with long thin beaks). Hence, a type of DIRECTIONAL selection
The question is incomplete as it does not have the options which are:
A) chordate.
B) echinoderm.
C) nematode.
D) mollusc.
Answer:
A) chordate.
Explanation:
The animals can be distinguished based on embryonic development and are categorized into two types: Deutrostomes and the protostomes.
The deuterostomes are the organism in which the small opening in the embryo called the blastopore develops into the anus. The deuterostomes organism belongs to two groups of the animal: the echinoderms and the chordates.
The chordates are the animals which possess the bilateral symmetry that is can be divided into left and right sides and posses true cavity or coelom.
Thus, Option-A is correct.
