chapter 14 study review

Question 1

what chromosomes are found in each human egg cell?

Answer 1

sex chromosomes?

Question 2

what is the probability that an offspring will be male?

Answer 2

50%

Question 3

what percentage of human sperm cells carry an X chromosomes?

Answer 3

50%

Question 4

how many chromosomes are in a normal human karyotype?

Answer 4

46-23 pairs

Question 5

where are sex-linked genes found?

Answer 5

on the sex chromosomes, x or y; mostly x

Question 6

why is colorblindness more common in males than in females?

Answer 6

because the gene for colorblindness is on the x chromosome, which males have 1 of and females have 2

Question 7

what sex chromosomes do males have?

Answer 7

XY

Question 8

what forms a Barr body?

Answer 8

in females, when the genes in one of the X chromosomes randomly switch

Question 9

what do you know about a cat if it has spots of more than one color?

Answer 9

that it is female?

Question 10

what ABO blood type genotypes result in the same phenotypes?

Answer 10

?

Question 11

in a pedigree, what do you know about an individual that is dominant?

Answer 11

their symbol will be shaded

Question 12

in a pedigree, what do you know about an individual that has a recessive trait?

Answer 12

their symbol will not be shaded

Question 13

what do the different symbols in a pedigree represent?

Answer 13

a circle is female and a square is male

Question 14

what human condition from our textbook does not appear in humans until late in a person’s life?

Answer 14

huntington’s disease

Question 15

what is sickle cell disease caused by?

Answer 15

a defective allele

Question 16

in cystic fibrosis, a change in a single gene causes the proteins CFTR to do what?

Answer 16

fold improperly

Question 17

why are people that are heterozygous for sickle cell disease generally healthy?

Answer 17

they usually have some normal hemoglobin in their red blood cells

Question 18

what is the failure of chromosomes to separate during meiosis called?

Answer 18

nondisjunction

Question 19

according to info in our book, what has no baby ever been born without?

Answer 19

?

Question 20

what sex chromosomes are necessary in order to be female?

Answer 20

XX

Question 21

what can be used to cut DNA so it can be studied?

Answer 21

restriction enzymes

Question 22

what field was formed because of the overlap of biology and information sciences?

Answer 22

bioinformatics

Question 23

about how much of our DNA has the instructions for building proteins?

Answer 23

2%

Question 24

why is it helpful to sequence many human genomes instead of just one?

Answer 24

so scientists can find how the human genome varies

Question 25

what is the human genome project?

Answer 25

a research effort to sequence all of our DNA and locate within it all of the functionally important sequences, such as genes

Question 26

what is true of more than 40% of the proteins coded for in the human genome?

Answer 26

they’re similar to proteins found in other organisms

Question 27

what prevents insurance companies from discriminating against people based information derived from genetic tests?

Answer 27

discrimination based on genetic information is against the law

Question 28

what chromosomes determine sex in humans?

Answer 28

the x and y

Question 29

how is the probability of having an offspring of a particular sex related to the sex of previous offspring?

Answer 29

?

Question 30

what tool can be used to determine if an individual has inherited the normal number of chromosomes?

Answer 30

a karyotype

Question 31

from which parent does a boy who is colorblind inherit this trait?

Answer 31

his father

Question 32

which blood alleles are codominant?

Answer 32

AB

Question 33

if there are 3 different alleles for blood type and two are codominant, how many different blood types are possible?

Answer 33

4

Question 34

what diagram can follow the inheritance of a single trait through generations in a family?

Answer 34

pedigree

Question 35

in which disorder does a female inherit only one X chromosome?

Answer 35

turner’s syndrome

Question 36

in which disorder does a male inherit an extra X chromosome?

Answer 36

klinefelter’s syndrome

Question 37

what is the study of whole genomes known as?

Answer 37

genomics

Question 38

if a man who is not colorblind and a woman who is a carrier have a son, what is the probability that he will be colorblind?

Answer 38

25%

Question 39

why is a person who has Klinefelter’s syndrome a male?

Answer 39

because males with Klinefelter’s are born with an extra X chromosome (XXY)

Question 40

if you were looking at a diagram of meiosis, how could you tell if nondisjunction had occurred?

Answer 40

?