Final Terms Part 4

Question 1

sister chromatid

Answer 1

replica of chromosome - attached at centromere

Question 2

homologous chromosomes

Answer 2

chromosomes that code for the same traits, but can be different
-one from each parent

Question 3

monohybrid cross

Answer 3

cross to study one trait

gave raise to law of segregation

Question 4

dihybrid cross

Answer 4

cross to study two traits

gave raise to law of independent assortment

Question 5

law of segregation

Answer 5

two alleles segregate from each other during the formation of the gametes in anaphase I of meiosis
half gametes have one allele, thus union of gametes is random

Question 6

law of independent assortment

Answer 6

pairs of alleles for genes on different chromosomes segregate independently in the formation of gametes during meiosis

Question 7

testcross

Answer 7

used to determine genotype of an organism displaying dominant phenotype by mating it with a homozygous recessive

Question 8

codominance

Answer 8

gene products are equally expressed

AB blood type

Question 9

incomplete dominance

Answer 9

homozygous dominant gives two gene products (ie dark red)
homozygous recessive gives no product
hets give intermediate (ie light red/pink)

Question 10

epistatis

Answer 10

form of gene interactino in which one gene interferes with the expression of another gene

Question 11

haplosufficiency

Answer 11

one gene product is sufficieny for life

Question 12

x-linked

Answer 12

trait is found on the x chromosome

Question 13

hemizygosity

Answer 13

males are hemizygous-have one x and one y

Question 14

SRY in humans

Answer 14

sex-determining region
becomes active in embryo
encodes testes determining factor

Question 15

Barr bodies

Answer 15

inactive X chromosome in females- used to set gene dosage

Question 16

gene dosage

Answer 16

the amount of gene product expressed

Question 17

pleiotropy

Answer 17

one gene is responsible for multiple phenotypes

Question 18

penetrance

Answer 18

the % of people with the genotype that express the phenotype

Question 19

expressivity

Answer 19

the range of phenotypes

Question 20

phenotypic variation

Answer 20

influenced by environment
epigenetics
modifier genes

Question 21

maternal effect

Answer 21

phenotype of offspring is determined by the nuclear genotype of mother

Question 22

extranuclear inheritance

Answer 22

typically maternal inheritance

DNA found in mitochondria and chloroplasts

Question 23

polygenetic

Answer 23

many genes

Question 24

multifactorial

Answer 24

many environmental factors

Question 25

discrete trait

Answer 25

traits have clear cut phenotypes

Question 26

quantitative trait

Answer 26

trait with a range of phenotypes with continuous distribution

Question 27

continuous variation

Answer 27

lines between phenotypes vary -quantitative traits

Question 28

heritability

Answer 28

the degree to which traits are influenced by genetics

Question 29

quantitative trait loci

Answer 29

used to determine gene archecture

Question 30

genetic drift

Answer 30

variation in gene frequency due to founder effect or bottle necking

Question 31

bottleneck

Answer 31

the population size is drastically reduced

Question 32

founder effect

Answer 32

population is based from a small number of breeding individuals

Question 33

natural selection

Answer 33

natural selects for traits that are advantageous

Question 34

gene pool

Answer 34

the number of alleles in a population

Question 35

migration

Answer 35

individuals moving in and out of a population

Question 36

gene flow

Answer 36

flow of alleles in or out of a population

Question 37

selective mating

Answer 37

most organisms do not mate randomly

positive and negative mating

Question 38

genomics

Answer 38

the study of an entire genome or genomes

Question 39

functional genomics

Answer 39

global analysis of the function of sequences in a genome especially useful when considering complex traits

Question 40

comparative genomics

Answer 40

comparison of entire genome from different species, individuals, or groups

• genetic variation
• evolutionary variation