genetics

Question 1

trisomy 21

Answer 1

down syndrome

Question 2

trisomy 18

Answer 2

edwards syndrome

Question 3

trisomy 13

Answer 3

patau syndrome

Question 4

p arm

Answer 4

petite arm

Question 5

q arm

Answer 5

longer arms

Question 6

genotype

Answer 6

two allele copies make up genotype. genetic makeup

Question 7

phenotype

Answer 7

physical manifestations

Question 8

autosomal dominant

Answer 8

vertical transmission. only one allele of a gene needed for expression. (postaxial polydactyly)

Question 9

autosomal recessive

Answer 9

2 copies of a gene needed to influence phenotype. (tyrosinase-negative albinism)

Question 10

X-linked recessive

Answer 10

all daughters of affected males are heterozygous carriers. female carriers transmit the affected allele to 50% of sons and daughters. (Duchenne muscular dystrophy)

Question 11

x-linked dominant

Answer 11

very rare. males transmit the trait to only females. 100% of females. Females transmit the trait to males and females (50% of offspring) (hypophosphatemia)

Question 12

reduced penetrance

Answer 12

phenotype occurring in less than 100% of individuals inheriting the gene. (retinoblastoma 90% penetrance)

Question 13

Variable expressivity

Answer 13

range of phenotypes that vary between individuals with specific genotype. (neurofibromatosis)

Question 14

Locus heterogeneity

Answer 14

single disorder, trait, or pattern of traits caused by mutations in genes at different chromosomal loci. (osteogenesis imperfecta).

Question 15

crossing over occurs during what phase of meosis

Answer 15

prophase 1

Question 16

mosaicism

Answer 16

one of the x chromosomes in a female in each cell is inactivated.

Question 17

nondisjunction

Answer 17

homologs fail to separate properly

Question 18

aneuploid

Answer 18

cells with abnormal chromosome number

Question 19

euploid

Answer 19

cells with normal number of chromsomes

Question 20

prader willi syndrome

Answer 20

paternal chromosome is deleted

Question 21

angelman syndrome

Answer 21

maternal chromosome is deleted