9.9 Single Gene Inheritance 1 and 2 Flashcards Preview

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Flashcards in 9.9 Single Gene Inheritance 1 and 2 Deck (39)
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1
Q

Tay-sachs disease is an example of what inheretence pattern?

A

autosomal recessive inheretence

2
Q

in X-linked dominant inheretence, is a male is affected, what is the outcome of the daughter?

A

The daughters would definitely be affected. They inheret the X from their father.

3
Q

autosomal dominance pattern of inheritance displays vertical inheritance, which means:

A

usually the phenotype appears in every generation

4
Q

X-inactivation is a random event, so most females have the paternal X in ____ of their cells and maternal X in _____ of their cells. can this change?

A

half, half

yes, some females can have different proportions

5
Q

neurofibromatosis shows _______ expression

A

variable

6
Q

an all-or-none phenomenon. You either show features of the genotype or not at all. Even though they have the mutated gene, not everyone who has the gene gets the disease.

A

reduced penetrance

7
Q

is there a gender bias in autosomal dominance pattern of inheritance?

A

no

8
Q

in X-linked inheretence in general, can fathers pass on the disease to their sons?

A

NO

9
Q

what type of inheretence pattern is this pedigree?

A

autosomal dominance pattern of inheritance

10
Q

The position of a gene on a chromosome

A

locus

11
Q

why do some females have milder or more severe phenotypes of X-linked diseases?

A

Lyon hypothesis - they have different proportion of active and in-active X-linked genes.

12
Q

what pattern of inheretence is this?

A

autosomal recessive

13
Q

in autosomal recessive inheretence, the parents of an affected individual are usually _______

A

unaffected

14
Q

in X-linked recessive inheretence, an affected father will make all of his daughters what?

A

carriers. all of them recieve the x* from their dad

15
Q

the finding that females express only one allele of their X-linked genes, although they actually have two. Ensures that females do not produce twice the gene product. What is this called?

A

dosage compensation

16
Q

When mutant genes produce effects on multiple organ systems and functions.

A

plieotropy

17
Q

in autosomal recessive inheretence, is there a gender bias?

A

no

18
Q

BRCA1 mutation causes cancer in 80% of people with the genotype, while 20% of people with the genotype do not get cancer. what is this called?

A

reduced penetrance

19
Q

individuals with the same geneotype have different phenotypes. Differences in location, size, number of neurofibromas for example in neurofibromatosis. Range of signs and symptoms.

A

variable expression

20
Q

what can help explain variable expression in females?

A

the Lyon hypothesis

21
Q

neurofibromatosis shows which type of inheretence?

A

autosomal dominance pattern of inheritance

22
Q

1 allele at a locus

A

hemizygote

23
Q

autosomal dominance pattern of inheritance does/doesn’t skip generations

A

doesn’t

24
Q

in female somatic cells, _____ X-chromosome is active

A

one

25
Q

Duchenne muscular dystrophy is an example of what type of inheretence?

A

X-linked recessive inheretence

26
Q

Marfan syndrome affects many different organ systems of the body. What is this called?

A

pleiotropy

27
Q

when abnormal phenotype is caused by mutations at 2 or more separate loci. Same condition caused by mutation of different genes

A

locus heterogeneity

28
Q

when the abnormal phenotype is caused by different mutations at the same gene (same locus)

A

allelic hetergeneity

29
Q

Alternative forms of the gene found at the same locus on homologous chromosomes.

A

allele

30
Q

what type of inheretence pattern is this?

A

x-linked dominant

31
Q

in female somatic cells, one X-chromosome is ______ and one is condensed and represented as the ____________

A

active

Barr body

32
Q

the BRCA1 mutation shows what type of inheretence?

A

autosomal dominance pattern of inheritance

33
Q

what type of genetic inheretence exhibits horizontal inheretence? what does this mean?

A

autosomal recessive inheretence

it means that affected individuals are usuallly seen in one sibship

34
Q

in autosomal dominance pattern of inheritance, _____ affected people have an affected parent

A

all

35
Q

Hemophilia A is an example of what pattern of inheretence?

A

X-linked recessive inheretence

36
Q

Marfan syndrome shows what pattern of inheretence?

A

autosomal dominance pattern of inheritance

37
Q

in autosomal dominance pattern of inheritance, _______ of the offspring of affected parents are affected

A

half

38
Q

Tay-sachs disease is an example of a disease concentrated in ____________, such as the Ashkenazi jews

A

genetic isolates

39
Q

what pattern of inheretence is this?

A

x-linked recessive