Ap Bio Heredity

Question 1

gene

Answer 1

part of a chromosome

Question 2

allele

Answer 2

type of gene

Question 3

Homologous Chromosomes

Answer 3

carry the same genes, but possibly different alleles

Question 4

Homozygous dominant

Answer 4

BB

Question 5

Heterozygous

Answer 5

Bb

Question 6

Homozygous recessive

Answer 6

bb

Question 7

Law of segregation

Answer 7

Each allele is packaged in a separate gamete (you pass on half your traits to your offspring)

Question 8

Law of independent assortment

Answer 8

genes are passed on independently of each other, because of the way they line up in metaphase

Question 9

Pleiotropy

Answer 9

a gene affects more than one phenotypic character (most genes are pleiotropic)

Question 10

Epistasis

Answer 10

one gene masks another gene

Question 11

Polygenic Inheritance

Answer 11

traits on a spectrum

Question 12

Mating of close relatives

Answer 12

more likely to carry the same recessive alleles

Question 13

multifactorial disorders

Answer 13

have genetic and environmental components

Question 14

incomplete dominance

Answer 14

When neither alleles are dominant or recessive and when there is a heterogygous genotype, the phenotype is a mix of the two alleles.

Question 15

X-linked (sex linked)

Answer 15

the X chromosome carries the trait. A male will always be affected by this trait if he has one of the alleles (it doesn’t matter if it’s dominant or recessive). A female is not always affected.

Question 16

Pedigree

Answer 16

shows phenotypes throughout generations

Question 17

linked genes

Answer 17

genes that are close together on a chromosome and aren’t likely to be separated by crossing over

Question 18

Polyploidy

Answer 18

an organism with more than two sets of chromosomes

Question 19

Recombinant offspring

Answer 19

show new combinations of parental traits (only if crossing over happens)

Question 20

If 50% of offspring are recombinants, there is

Answer 20

a 50% frequency of recombination

Question 21

Why is 50% the maximum frequency of recombination?

Answer 21

Independent assortment (2 of 4 strands are involved in crossing over)

Question 22

X inactivation

Answer 22

females inherit two x chromosomes, and one x in each cell is randomly inactivated (different for each cell)

Question 23

codominance

Answer 23

both alleles contribute to phenotype of organism (neither dominant or recessive). both traits show up (don’t mix)

Question 24

Karyotype

Answer 24

A display of the chromosome pairs of a cell

Question 25

consanguineous mating

Answer 25

mating between close relatives

Question 26

Amniocentesis

Answer 26

needle puncture of the amniotic sac to withdraw amniotic fluid for analysis

Question 27

chronic villus sampling

Answer 27

sampling of placental tissues for prenatal diagnosis

Question 28

Barr body

Answer 28

a dense body formed from a deactivated x chromosome

Question 29

Down syndrome

Answer 29

trisomy 21

Question 30

aneuploidy

Answer 30

abnormal number of chromosomes