lecture 2/1/16

Question 1

which of the following most influences the development of a female fetus?

Answer 1

• BC
  the precedence of any two X chromosomes
  the presence of a y chromosome

Question 2

if a man has an x- linked recessive disease, can his sons inherit that disease from him?

Answer 2

-no, all his sons inherit their x chromosomes maternally

Question 3

why do some people have unusual chromosome combinations, such as XYY and XXX

Answer 3

-errors occurred in chromosomes segregation during meiosis in their fathers or mothers

Question 4

which of the following inheritance patterns includes an environment contribution

Answer 4

-multifactorial

Question 5

how is co-dominant inheritance different from incomplete dominant inheritance?

Answer 5

• in codomincance two alleles are expressed equally; in incomplete dominance neither the dominant or recessive phenotypes seen in heterozygotes

Question 6

what determines biological sex?

Answer 6

Sex hormones produced by gonads

Question 7

sex hormones are produced by what

Answer 7

gonads

Question 8

in a fetus, sex hormones shape development of ______________

Answer 8

sexual anatomy

Question 9

humans have _____pairs of chromosomes

Answer 9

23

Question 10

out of 23 chromosomes 22 pairs are ______

Answer 10

autosomes

Question 11

in the absence of a Y chromosome, a fetus will

Answer 11

develop into a female

Question 12

females are

Answer 12

XX

Question 13

males are

Answer 13

XY

Question 14

sons inherit Y chromosome from the _____

Answer 14

father

Question 15

sons inherit X chromosome from the _____

Answer 15

mother

Question 16

SRY gene on ______chromosome signals testes to develop

Answer 16

Y

Question 17

testes produce ____

Answer 17

testosterone

Question 18

if the sperm has an x chromosome, an embryo will usually develop __________

Answer 18

female sexual organs

Question 19

ovaries produce

Answer 19

estrogen

Question 20

a phenotype that is determined by allele on an X chromosome

Answer 20

x linked trait

Question 21

normal copy on one X chromosome masks the recessive disease allele on the other x chromosome

Answer 21

recessive x linked trait

Question 22

a male has a single x chromosome so he will show the effect of any recessive allele located on his

Answer 22

x chromosomes

Question 23

a family tree where you can track the traits; a visual representation of the occurrence of phenotypes across generations

Answer 23

a pedigree

Question 24

very small and few genes; study ancestry and identify paternity

Answer 24

y chromosome

Question 25

a form of inheritance in which heterozygotes have a phenotype that is intermediate between homozygous dominant and homozygous recessive

Answer 25

incomplete dominance

Question 26

three blood group alleles : A,B, and O

genotypes: OO, AO, BO, AB,AA , and BB

Answer 26

blood types

Question 27

both maternal and paternal alleles contribute equally and separately to the phenotype

Answer 27

codominance

Question 28

blood type alleles A and B are codominant . O is ________ to both A or B

Answer 28

recessive

Question 29

a single straight determined by the interaction between alleles of more than one gene; i.e. human height

Answer 29

polygenic trait

Question 30

height shows

Answer 30

continuous variation

Question 31

range of variable phenotypes rather that

Answer 31

discrete categories

Question 32

interactions between genes and environment contributes to a phenotype

Answer 32

multifactorial trait

Question 33

stress and mental development

allele of serotonin transport protein interact with

Answer 33

environment

Question 34

one serotonin allele increases susceptibility to

Answer 34

environmental stress

Question 35

failure of chromosomes to separate during cell division

Answer 35

nondisjunction

Question 36

an abnormal number of one or more chromosomes

Answer 36

aneuploidy