BIO Chapter 8

what is the minimum number of alleles that is required for a genetic disorder to be expressed: X-linked recessive disorder in a male

1 allele

what is the minimum number of alleles that is required for a genetic disorder to be expressed: autosomal dominant disorder in a male

1 allele

if the mother has two copies of the dominant allele she must donate the dominant allele to the offspring. therefore there is a _________% chance that the offspring will inherit and express the disorder

100

what is the minimum number of alleles that is required for a genetic disorder to be expressed: X-linked recessive disorder in a female

2 alleles

what is the minimum number of alleles that is required for a genetic disorder to be expressed: autosomal recessive disorder in a female

2 alleles

human cells possess __________ pairs of chromosomes. On average, a human chromosome contains __________ different genes. If a human has two variants of a gene at the same locus they are __________ for that gene. If the two alleles are identical at the same locus the person is __________ for that gene.

23, over a thousand, heterozygous, homozygous

a woman carries two alleles for an autosomal dominant genetic condition. Her husband does not possess the allele. What are the chances that their offspring would inherit the condition? a. 100% b. 25% c. 50% d. 0%

a

both parents of a newborn are heterozygous for an autosomal dominant genetic disorder. What are the odds that the newborn would also display the disorder? a. 3/4 b. 1/4 c. 1/2 d. 0/4

a

can occur with a single dominant allele a. dominant disorder b. sex-linked disorder c. recessive disorder

a

can occur in the presence of a single recessive allele a. dominant disorder b. sex-linked disorder c. recessive disorder

a, b, c

a woman is a carrier for two recessive genetic conditions, one is carried on chromosome 5 and one is carried on the X chromosome. Which of the following statements is true regarding the inheritance of these two traits? a. the trait carried on chromosome 5 can be inherited by an offspring of either sex. b. a son is more likely than a daughter to inherit the recessive allele carried on the mother's X chromosome. c. the trait carried on the X chromosome is more likely to be expressed in a son than in a daughter. d. the trait carried on the X chromosome can be inherited by an offspring of either sex.a.

a, c, d

you meet a young man with hemophilia, an X-linked, recessive disorder. While talking to him, he mentions that his maternal grandfather also had hemophilia, but his parents do not. Which of the following statements about his family would be correct? a. his mother is a genetic carrier for hemophilia. b. his father is a genetic carrier of hemophilia. c. he could pass the gene for hemophilia on to his future sons. d. he could pass the gene for hemophilia on to his future daughters. e. his maternal grandmother also had hemophilia. His sister would also be a hemophiliac

a, d

chromosomes contain multiple genes which have different versions called __________

alleles

analyzing the pattern of inheritance for a genetic condition can help determine the mode of inheritance. If a genetic condition is not present in either parent but is sometimes inherited by their offspring, the condition is likely __________ __________. If a genetic condition is not present in either parent, and is never inherited by their offspring, but when either parent is affected by the condition, their offspring have at least a 50% chance of inheriting it, the condition is likely __________ __________. If a genetic condition is more readily expressed by male offspring than female offspring, the condition is likely __________.

autosomal recessive, autosomal dominant, sex-linked

if a recessive trait is carried on the X chromosome, which sex is more likely to express the trait? a. female b. male c. the odds are the same for both male and female

b

what are the odds that two carriers for cystic fibrosis, an autosomal recessive disorder, would have an offspring with the cystic fibrosis disorder? a. 3/4 b. 1/4 c. 1/2 d. 0/4

b

can be passed to the next generation by a carrier a. dominant disorder b. sex-linked disorder c. recessive disorder

b, c

can occur with two recessive alleles a. dominant disorder b. sex-linked disorder c. recessive disorder

b, c

which of the following statements is true regarding a recessive trait that is carried on the X chromosome? a. females are more likely to express the trait. b. males can express the trait. c. males are more likely to express the trait. d. females can express the trait. e. both sexes are equally likely to express the trait.

b, c, d

a man possesses one allele for a dominant genetic condition carried on chromosome 12, and one for a recessive genetic condition carried on chromosome 20. Which of the following statements is true regarding the inheritance of these two traits? a. his offspring cannot inherit both genetic condition alleles. b. his offspring is more likely to express the dominant genetic condition than the recessive condition. c. his offspring is more likely to inherit the dominant condition allele than the recessive condition allele. d. his offspring may not inherit either genetic condition allele.

b, d

which of the following genetic relationships in a human cell is accurate? a. human cell should contain more chromosomes than genes. b. a human cell should contain more homologues than chromosome pairs. c. a human cell should contain fewer alleles than homologues. d. a human cell should contain about twice as many alleles as gene loci.

b, d

two of her offspring display the recessive condition, which indicates that they have homozygous recessive genotypes. This can only occur if the offspring inherited a recessive allele from [one or both] parents.

both

a woman is a carrier for a recessive X-linked genetic condition, and her husband does not possess the allele. What are the odds that the couple's son will express the condition? a. 100% b. 25% c. 50% d. 0%

c

frank's sister is known to carry an allele for a single-gene recessive genetic disorder that is fatal in very early life. Frank's mother was tested for the allele and found not to carry it. What are the odds that Frank is a carrier for the allele? a. 1/1 b. 1/4 c. 1/2 d. 1/8

c

if an XX female mates with an XY male, what are the chances that they produce a female offspring? a. 100% b. 75% c. 50% d. 0%

c

a man possesses one copy of an allele for an autosomal dominant genetic condition. His wife does not possess the allele. What are the chances that their first daughter would inherit the condition? a. 100% b. 25% c. 50% d. 75%

c, because the condition is dominant

__________ contain multiple genes which have different versions called alleles

chromosomes

a man is homozygous for an autosomal recessive genetic condition. His mate does not possess the allele. What are the chances that their first son would express the condition? a. 100% b. 25% c. 50% d. 0%

d

in which of the following scenarios is the offspring most likely to express the genetic condition? a. only the father is a carrier for an X-linked recessive condition. The offspring is a male. b. only the mother is a carrier for an X-linked recessive condition. The offspring is a female. c. both parents are a carrier for an autosomal recessive condition. The offspring is a female. d. only the mother is a carrier for an X-linked recessive condition. The offspring is a male.

d

a man possesses an allele for a recessive X-linked genetic condition, and his wife does not possess the allele. What are the odds that the couple's son will express the condition? a. 100% b. 25% c. 50% d. 0%

d. 0%

a change in a single gene [does or does not] affect chromosome number or size, which are what a karyotype analysis can detect.

does not

this mother does not display the disorder and therefore has at least one __________ allele. Because one child displays the disorder, she must also carry the recessive allele. Therefore, this mother is a genetic carrier (Aa).

dominant

if the trait is dominant, [both or either] sex would express the trait by inheriting only one copy of the dominant allele.

either

t or f: an analysis of a karyotype can help to determine whether someone has a genetic disorder caused by a single gene.

f

t or f: females can express a trait that is carried on the Y chromosome.

f

t or f: if an individual's genetic disorder is successfully treated by gene therapy, the patient's offspring are also protected.

f

t or f: sex-linked traits (traits carried on either the X or Y chromosome) can only be expressed in one sex or the other.

f

t or f: a male is more likely than a female to express a dominant trait that is carried on the X chromosome.

f

a __________ does not carry a Y chromosome, which can be identified in a karyotype as a much smaller chromosome in the pair of sex chromosomes. In this karyotype, all chromosome pairs are relatively the same in size.

female

a __________is a locus on a chromosome that usually codes for a protein. There are two alleles for each __________, one on each chromosome homologue.

gene

chromosomes contain multiple __________ which have different versions called alleles

genes

if a condition is dominant the offspring needs to inherit __________ copy of the allele to inherit and express the condition.

one

males carry only one X chromosome. Therefore, if a genetic disorder is associated with the X chromosome, males only need to possess __________ copy of the allele to express the trait.

one

a diagram similar to a family tree that illustrates genetic relationships is called a _________. These diagrams can be analyzed to investigate the inheritance patterns of genetic disorders. A genetic disorder that appears in an offspring of a family that has no history of the disorder is likely a _________condition. Such an outcome suggests that _________ parent(s) acted as a carrier for the disorder.

pedigree, recessive, both

t or f: if only one parent is a carrier for an autosomal recessive disorder, and the other parent is homozygous and does not have the disorder, there is no chance that the offspring would inherit the disorder.

t

t or f: in humans, the sex of an offspring is determined solely by the chromosomes donated by the male parent.

t

t or f: many genes are present on each chromosome.

t

what does a sex chromosome pair in the karyotype of a healthy individual shown.

the pair of sex chromosomes can be easily identified in a karyotype of a male, because the X chromosome is larger than the Y chromosome.