Chat with AIExam 2: Heredity and Evolution
Two people (both heterozygotes) are able to taste a chemical substance called PTC. The ability to taste PTC is caused by a dominant allele (T). The inability to taste PTC is caused by a recessive allele (t). What proportion of their offspring would be expected to be heterozygous?
(27) 
VerifiedB
Allele frequencies are indicators of the genetic makeup of a population. Use the example of ABO blood types to show how allele frequencies change.
(35) 
Answered by Examlex AI CopilotAllele frequencies are indicators of the genetic makeup of a population, and they can change over time due to various factors such as natural selection, genetic drift, and gene flow. One example of how allele frequencies change can be seen in the case of ABO blood types.
The ABO blood type system is determined by the presence of three alleles: A, B, and O. The A and B alleles are co-dominant, while the O allele is recessive. This means that individuals can have blood type A (AA or AO genotype), blood type B (BB or BO genotype), blood type AB (AB genotype), or blood type O (OO genotype).
In a population, the frequency of each allele can change due to factors such as migration, genetic mutations, and natural selection. For example, if a population experiences an influx of individuals with a high frequency of the B allele due to migration, the overall frequency of the B allele in the population will increase. Conversely, if natural selection favors individuals with the A allele due to a particular environmental factor, the frequency of the A allele may increase over time.
Additionally, genetic drift, which refers to random changes in allele frequencies due to chance events, can also impact the distribution of ABO blood types in a population. For example, a small population that experiences a bottleneck event may have a different distribution of ABO blood types compared to a larger, more diverse population.
Overall, the example of ABO blood types demonstrates how allele frequencies can change within a population over time due to various genetic and environmental factors. Studying these changes can provide valuable insights into the genetic diversity and evolutionary history of a population.
Which of the following is not inherited in a Mendelian fashion?
(32) VerifiedE
Melanin production is the result of interactions between several different loci.
(37) Explain why a woman with type O blood and a man with type A blood could potentially have children with either type A or O blood.
(33) At a hypothetical locus, a man's genotype is Aa. What proportion of his gametes would be expected to receive the A allele?
(31) Which of the statements below is false regarding the relationship between malaria and the HbS allele?
(39) Explain the concepts of dominance, co-dominance, and recessiveness as used in modern genetics.
Using the HbS allele to illustrate, describe why fitness levels are a function of the environment.
(28) A manifestation of sickle-cell anemia is the abnormal hemoglobin S reduces the ability of red blood cells to transport oxygen throughout the body.
(35) Mendelian traits are described as discrete, or discontinuous because
(37) Polygenic traits account for few, if any, of the readily observable phenotypic variation seen in humans.
(38) Evolution can be described as a two-stage process that includes which of the following?
(35) What is the only source of new genetic material in any population?
(43) 
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