Exam 19: Genetics and Inheritance

The trend toward increased height and weight due to improved nutrition in certain human populations is an example of the effect of ________ on phenotypes.

In incomplete dominance, the phenotype of the heterozygous genotype is an intermediate between the phenotype of either homozygous genotype.

Which of the following is most likely involved in the determination of intelligence?

Sickle-cell anemia is a disease that alters the structure of hemoglobin, and in turn, can cause severe health problems in individuals if left untreated. The disease is expressed in homozygous recessive individuals, whereas the heterozygous condition usually does not result in any symptoms of the disease. Sickle-cell anemia primarily affects Africans and Caucasians of Mediterranean descent. Typically, when a disease occurs only in the homozygous recessive condition, the incidence of the gene in the population is predicted to decline overtime, particularly when it can be detected either phenotypically or by genetic testing. In East Africa, the disease still occurs in about 40% of the population. Give an explanation for why the incidence of the disease has remained so high in African populations.

Based on the information below, answer the following two questions, assuming complete dominance. "In humans, a widow's peak is a dominant trait, and a straight hairline is a recessive trait." -Cystic fibrosis is a genetic disorder that results from the inheritance of two recessive alleles. What is the chance that a child will inherit the disorder if one parent is heterozygous for this gene and one parent has cystic fibrosis?

The Punnett square is a useful tool for

A phenotypic trait is considered sex-linked when

In the human male, genotype and phenotype associated with the genes on the X chromosome are determined by the one X chromosome he inherits from his mother.

A couple has a daughter who is color-blind. The mother is not color-blind, but the father is. What is the genotype of the mother for this trait?

Which of the following is characteristic of Klinefelter syndrome?

A recessive trait can be inherited through complete dominance only if both parents are heterozygous for the trait.

Based on the information below, answer the following three questions, assuming complete dominance. "In humans, the ability to roll the tongue is a dominant trait; the inability to roll the tongue is a recessive trait." -If two individuals homozygous dominant for this trait have a child, what is the chance that the child will not be able to roll his tongue?

Based on the information below, answer the following two questions, assuming complete dominance. "In humans, a widow's peak is a dominant trait, and a straight hairline is a recessive trait." -If an individual homozygous dominant for widow's peak has a child with an individual heterozygous for widow's peak, what is the chance that the child will have a widow's peak?

When a piece of chromosome breaks off and reattaches at another site on the same or another chromosome, this is called

Based on the information below, answer the following three questions, assuming complete dominance. "In humans, the ability to roll the tongue is a dominant trait; the inability to roll the tongue is a recessive trait." -If two individuals heterozygous for this trait have a child, what is the chance that the child will not be able to roll his tongue?

Genes located on the same chromosome are not always inherited together because of the process of ________, which occurs during meiosis; this process "reshuffles" the genes.

Which one of the following genetic disorders is caused by the inheritance of a dominant-lethal allele?

Failure of sister chromatids to separate properly is called

If both alleles of a particular gene are identical, the person is said to be

Alternative versions of the same gene are ________.