The answer is either A, the bottleneck effect or C, natural selection. The answer is most likely A because it is hinted that the predator fish was placed in the isolated stream. The predators eating the darters less than 5cm is natural selection though.
A high level of gene flow into a population increases genetic diversity in a population. A high level of gene flow out of a population decreases genetic diversity in a population. Genetic drift is the change in allele frequencies due to "sampling error" factors. Typically, genetic drift has the biggest impact on small populations.
Gene flow (or gene migration) is a mechanism of evolution (change the allele frequencies) which transfers genetic variation among populations due to migration. High level of gene flow decreases the genetic differentiation between the two populations.
Genetic drift is a mechanism of evolution that acts by chance (“sampling error”) often when a population is reduced in size by a natural disaster (bottleneck effect) or when a small group leaves the main population and forms a colony (founder effect).
Answer:
b
Explanation:
i took this before and i know its b
A different form of a gene
Answer:
Allergens differ from antigens because *they do no stimulate the immune system resulting in the production of leukocytes rather than the stmulate the IgE antibodies*
Explanation:
Allergen and antigen are both foreign substances that can cause certain disorders to animals, but there is some difference between them in terms of their nature and the diseases caused by them. An allergen is a nonparasitic foreign substance that can cause certain immune reactions in the body when it enters the body. Whereas, an antigen is a foreign substance that can trigger the immune system to produce a specific immune response. This immune response leads to produce antibodies that can neutralize or destroy the foreign substances that entered the body.
Allergens can produce Systemic Allergic Response. Allergens stimulate the IgE antibodies by binding to them on the mast cells and causing the mast cells to rupture and release histamine, serotonin, and heparin, initiating inflammatory response.
