9.9 Single Gene Inheritance 1 and 2

Question 1

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

Answer 1

autosomal recessive inheretence

Question 2

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

Answer 2

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

Question 3

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

Answer 3

usually the phenotype appears in every generation

Question 4

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?

Answer 4

half, half

yes, some females can have different proportions

Question 5

neurofibromatosis shows _______ expression

Answer 5

variable

Question 6

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.

Answer 6

reduced penetrance

Question 7

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

Answer 7

no

Question 8

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

Answer 8

NO

Question 9

what type of inheretence pattern is this pedigree?

Answer 9

autosomal dominance pattern of inheritance

Question 10

The position of a gene on a chromosome

Answer 10

locus

Question 11

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

Answer 11

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

Question 12

what pattern of inheretence is this?

Answer 12

autosomal recessive

Question 13

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

Answer 13

unaffected

Question 14

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

Answer 14

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

Question 15

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?

Answer 15

dosage compensation

Question 16

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

Answer 16

plieotropy

Question 17

in autosomal recessive inheretence, is there a gender bias?

Answer 17

no

Question 18

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?

Answer 18

reduced penetrance

Question 19

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

Answer 19

variable expression

Question 20

what can help explain variable expression in females?

Answer 20

the Lyon hypothesis

Question 21

neurofibromatosis shows which type of inheretence?

Answer 21

autosomal dominance pattern of inheritance

Question 22

1 allele at a locus

Answer 22

hemizygote

Question 23

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

Answer 23

doesn’t

Question 24

in female somatic cells, _____ X-chromosome is active

Answer 24

one

Question 25

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

Answer 25

X-linked recessive inheretence

Question 26

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

Answer 26

pleiotropy

Question 27

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

Answer 27

locus heterogeneity

Question 28

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

Answer 28

allelic hetergeneity

Question 29

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

Answer 29

allele

Question 30

what type of inheretence pattern is this?

Answer 30

x-linked dominant

Question 31

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

Answer 31

active

Barr body

Question 32

the BRCA1 mutation shows what type of inheretence?

Answer 32

autosomal dominance pattern of inheritance

Question 33

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

Answer 33

autosomal recessive inheretence

it means that affected individuals are usuallly seen in one sibship

Question 34

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

Answer 34

all

Question 35

Hemophilia A is an example of what pattern of inheretence?

Answer 35

X-linked recessive inheretence

Question 36

Marfan syndrome shows what pattern of inheretence?

Answer 36

autosomal dominance pattern of inheritance

Question 37

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

Answer 37

half

Question 38

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

Answer 38

genetic isolates

Question 39

what pattern of inheretence is this?

Answer 39

x-linked recessive