Bio chapter 20

The genetic counselor pointed out that ________ is a genetic disorder that is dominant as well as latent, and is usually not seen until following reproductive years

Huntington disease

The device used in genetics to calculate the genotype and phenotype of a particular cross is called a:

Punnett square

Color blindness is an X-linked genetic disorder. If a man with normal vision and a heterozygous woman have a son, what are the chances that he will be color blind

25%

Amniocentesis reveals that an embryo has Tay-Sachs disease. What are the genotypes of the parents if they appear normal (t = Tay-Sachs)?

Tt x Tt

The __________ refers to the particular position of a gene on a chromosome

locus

If an albino (autosomal recessive trait) woman is married to a man with normal coloring and they have an albino child, what is the genotype of the man?

heterozygous

If one parent has type B blood and the other has type AB blood, what type blood might the child have

A, B, AB only

Knowing that sickle cell disease is caused by a codominant trait, if both parents have the sickle-cell trait (are heterozygous), what is the chance of a child also having the sickle-cell trait (heterozygous)?

50%

The perplexed parents did not understand why they were normal and they had a child with cystic fibrosis. How did the genetic counselor address their concerns

She explained that both parents were heterozygous

Which of the following is considered polygenic?

height

Color blindness is an X-linked genetic disorder. Choose the following genotype that represents a female with normal vision, but is a carrier of the color blind gene

XB Xb

The ____________ condition involves two identical alleles.

homozygous

A/an _______ is the possible form a gene may take.

allele

In a paternity suit the alleged father has blood type O, the mother blood type AB, and the baby has blood type B. Choose the most accurate statement below.

The alleged father could be the biological father

If one parent has type A blood and the other has type O blood, what blood type might the child have?

A or O

The _________ gamete determines the sex of the offspring.

male

___________ occurs when alleles are equally expressed in heterozygous individuals

Codominance

If Ashley is normal (hh) but her husband Robert has Huntington disease (Hh), what will be their baby's chance of escaping the disease entirely?

50%

Choose the following letter designation for dimples/no dimples that represents the heterozygous genotype.

Dd

A woman who can roll her tongue (dominant) is married to a man who cannot. Two of their four children can roll their tongues, and two cannot. If A = roll tongue and a = cannot roll tongue, then what is the genotype of the parents?

woman Aa x man aa

___________ occurs when the heterozygous condition exists as an intermediate between the two homozygotes

Incomplete dominance

Traits controlled by alleles on the sex chromosomes (X or Y) are said to be

sex-linked

In crossing two heterozygous parents, what are the chances for a pure recessive offspring?

25%

The genetic make-up of an individual is called the _________ and the physical make-up is called the ________.

genotype, phenotype

Knowing that the gene for widow's peak is dominant, if two heterozygous individuals have a child, what is the phenotypic ratio for their crossing?

3:1

The __________ trait takes over the expression of the _________ trait.

dominant/recessive

__________ is an autosomal recessive disorder that involves lysosomal dysfunction and has a higher incidence in individuals of Jewish descent

Tay Sach's disease

A certain flower displays incomplete dominance in which the homozygous condition RR is red, the homozygous condition rr is white, and the heterozygous condition (Rr) is pink. If two heterozygous plants are crossed, determine the phenotypic ration of the offspring

there will be equal numbers of red and white progeny and twice as many pink plants

___________ is genetic disease characterized by abnormally thick mucus in the bronchial tubes and pancreatic ducts of the patient.

Cystic fibrosis

If a mother has type AO blood and her husband has type BO blood, what are the potential phenotypes of their offspring?

type A
type B
type AB
type O
*** all of the above

Choose the following letter designation for syndactly/normal fingers that represents the homozygous dominant genotype.

SS

Color blindness is an X-linked genetic disorder. If a man with normal vision and a heterozygous woman have a son, what are the chances that he will be color blind?

50%