Exam 2 Mendelian Genetics

Which of the following crosses would always result in offspring that display only the dominant phenotype?

TT x tt

What aspect of Mendel's background gave him the necessary tools to discover the laws of inheritance?

He had studied mathematics and probability

What is the blending theory of inheritance?

an old theory stating that offspring show traits intermediate between those of parents

An individual with a dominant phenotype is crossed with an individual with a recessive phenotype; four of their nine offspring show the recessive phenotype. What is the genotype of the first parent?

Aa

If you had two guinea pigs of opposite sex, one homozygous black and one homozygous brown, but you didn't know which the dominant characteristic was, how would you find out the dominant color?

Mate them together and see what color the offspring are— that will be the dominant color

Unattached earlobes (EE or Ee) are dominant over attached earlobes (ee). A couple both have unattached earlobes. They notice that each of them has a parent with attached earlobes (ee). Therefore, they correctly assume that they are carriers for attached earlobes (Ee). The couple proceeds to have four children.

Two heterozygous, one homozygous recessive, and one homozygous dominant is a likely outcome, but all heterozygous, or two, three, or all four homozygous are also possible.

Of the following, which is an autosomal dominant disorder?

Huntingtons disease

A classical example of incomplete dominance is

pink flowers in heterozygous snapdragons

Individuals in the 1800s (when childhood hunger and diseases were common) averaged slightly over five feet tall, but their offspring in the 1900s were substantially taller on average. This reflects the influence of

environmental factors on the ability of genes to express themselves

Which disease results in deformed red blood cells, poor circulation, anemia, and an increased resistance to malaria?

Sickle-cell disease

Which of the statements below is true regarding the pattern of inheritance in the pedigree?

It is autosomal dominant; the children with one affected parent have a 50% chance of inheriting the allele.

A gene locus is

a dominant gene

Various forms of a gene at a given locus are called

alleles

Which of the following genotypes is homozygous?

aaBB

Which organism did Mendel utilize to work out the laws of segregation and independent assortment?

the garden pea

In a Punnett square, the letters within the little boxes represent

offspring genotypes

In a Punnett square, the letters within the little boxes represent

phenotypes

If all offspring of a cross have the genotype Aa, the parents of the cross are most likely

AA x aa

Who proposed the law of independent assortment?

Mendel

Blood types (A, B, and O) are controlled by

multiple alleles

The ABO blood types are controlled by

multiple alleles and codominance

Multiple effects of a single gene is

pleiotrophy

In genetic analyses, researchers know that linkage of genes will introduce exceptions to the principle of

independent assortment

A graph of phenotypic variation similar to the illustration below strongly suggests

polygenetic inheritance

A dihybrid cross uses "true breeding plants" that differ in

two traits

Any chromosome other than a sex chromosome (such as a sperm or an egg) is called a(an)

autosome

Sickle Cell Anemia is an example of

pleiotrophy

In the video we watched in class regarding Sickle Cell Anemia, we learned that there is a potenial cure using

Gene Therapy