lecture test 2

Question 1

lethal alleles

Answer 1

Causes death before individual can reproduce

Question 2

multiple alleles

Answer 2

Individual carries two alleles for each autosomal gene

Question 3

incomplete dominance

Answer 3

Heterozygous phenotype is intermediate between those of the two phenotypes

Question 4

codominance

Answer 4

heterozygous phenotype results from the expression of both alleles

Question 5

penetrance

Answer 5

amount of individuals in a population with that trait

Question 6

Expressivity

Answer 6

variety of train

Question 7

epistasis

Answer 7

phenomenon where one gene affects the expression of a second gene

Question 8

pleiotropy

Answer 8

where one gene controls several functions

Question 9

genetic heterogeneity

Answer 9

different genes can produce identical phenotypes

Question 10

Phenocopy

Answer 10

train that appears inherited but is caused by the environment

Question 11

Mitochondrial DNA

Answer 11

mtDNA contains 37 genes and transferred from mother to offspring and no crossing over, mutates faster

Question 12

mitochondrial disorders

Answer 12

results from mutation of the mtDNA

Question 13

heteroplasmy

Answer 13

mtDNA sequence is not the same in all copies of the genome

Question 14

linkage

Answer 14

genes that closed on the same chromosome are said to be linked

Question 15

recombination

Answer 15

chromosomes during crossing over in prophase 1 and form a new combination of alleles

Question 16

genetic markers

Answer 16

DNA sequencing that serves as land markers near genetic interest

Question 17

sexual development

Answer 17

5th week- all embryos develop 2 sets of unspecialized gonads, reproductive ducts.

Question 18

mullerian

Answer 18

female

Question 19

wolffian

Answer 19

male

Question 20

sex chromosomes

Answer 20

X and y chromosomes

Question 21

male sex chromosomes

Answer 21

heterogametic (xy)

Question 22

female sex chromosomes

Answer 22

homogametic (XX)

Question 23

x chromosomes

Answer 23

contains over 1,500 genes

Question 24

y chromosomes

Answer 24

contain 231 genes/ Junk DNA

Question 25

SRY gene

Answer 25

encodes a transcription factor protein

Question 26

y chromosome anatomy

Answer 26

has a short arm and a long arm

Question 27

PAR 1 and PAR 2

Answer 27

5% of the chromosome and 63 genes

Question 28

MSY

Answer 28

95% of the chromosome and essential for fertilization

Question 29

primary sex ratio

Answer 29

at conception

Question 30

secondary sex ratio

Answer 30

At birth

Question 31

Tertiary sex ratio

Answer 31

At maturity

Question 32

y linked traits

Answer 32

Very rare and male to male

Question 33

Female x linked traits

Answer 33

Passed down like autosomal traits

Question 34

Male x linked traits

Answer 34

single copy of x linked allele causes exprestion of illness

Question 35

recessive x linked traits

Answer 35

expressed in females when causative allele is present in 2 copies

Question 36

dominant x linked traits

Answer 36

rare, expressed differently between sex's, males are effected severely

Question 37

sex influenced traits

Answer 37

allele is dominant in one sex but recessive in the other

Question 38

polygenic traits

Answer 38

produces continuously varying phenotypes, quantitative traits. EX: finger prints, heigh, body weight and skin color.

Question 39

heritability

Answer 39

estimates the proportion of variation in a complex trait due to genetics. things that can affect this is environmental factors

Question 40

concordance

Answer 40

measures frequency of expression of traits in both monozygotic or dizygotic twins

Question 41

dizygotic twins

Answer 41

shared environment and 50% of genes

Question 42

Monozygotic

Answer 42

identical genotypes and shared environment

Question 43

cytogenetics

Answer 43

area of genetics that links chromosome variations to specific traits, including illnesses

Question 44

centromeres

Answer 44

Largest constriction of the chromosome and where spindles attach

Question 45

karyotypes

Answer 45

displays chromosomes arranged by size and structure, humans have 24 chromosomes, autosomes 1-22 and the sex chromosomes

Question 46

Amniocentesis

Answer 46

a needle is used to remove a small sample amount of amniotic fluid