4.4

Question 1

___ is the transmission of genetic characteristics from parent to offspring

Answer 1

heredity

Question 2

1 member of each ___ of chromosomes is inherited from the individual’s mother and the other from the father

Answer 2

homologous pair

Question 3

a female normally has ___ chromosomes

Answer 3

2 X

Question 4

which chromosomes do not determine the sex of an individual?

Answer 4

autosomes

Question 5

allele (def)

Answer 5

alternative forms of a gene are known as alleles

Question 6

cells contain pairs of chromosomes. Since they are the same size and shape and also code fo the same information, each pair of chromosomes is called which of the following?

Answer 6

homologous chromosomes

Question 7

what is true of recessive alleles?

Answer 7

their expression is masked in the presence of a dominant allele

they are expressed only when present on both of the homologous chromosomes

Question 8

the X and Y chromosomes are referred to as ___ chromosomes

Answer 8

sex chromosomes

Question 9

phenotype (def)

Answer 9

expression of genes as an observable trait (such as eye color)

Question 10

chromosomes X and Y are called the sex chromosomes because they determine the sex of an individual; all others are called ___

Answer 10

autosomes

Question 11

homozygous (def)

Answer 11

individuals w/ 2 identical alleles for a particular trait

Question 12

which term refers to a type of inheritance in which 3 or more alleles exist for the same gene?

Answer 12

multiple allele inheritance

Question 13

when both alleles of a heterozygote are expressed, that trait is described as a ___ trait

Answer 13

codominant

Question 14

codominance (def)

Answer 14

equally dominant alleles
both alleles of a heterozygote are expressed
both phenotypes are expressed

ex. red flower + white flower == red and white flower

Question 15

incomplete dominance (def)

Answer 15

describes the inheritance of a trait in which the heterozygote has an intermediate expression b/n either allele

ex. red flower + white flower == pink flower

Question 16

eye color and skin color are traits determined by genes at multiple loci. They are examples of which type of inheritance?

Answer 16

polygenic (multiple-gene) inheritance

Question 17

polygenic (multiple-gene) inheritance

Answer 17

genes at 2 or more loci, or even on different chromosomes, contribute to a single phenotypic trait

Question 18

ABO blood type is a trait that demonstrates which type of inheritance?

Answer 18

multiple allele

Question 19

which term refers to a phenomenon in which 1 gene produces multiple phenotypic effects (i.e. Alkaptonuria)?

Answer 19

polygenic inheritance

Question 20

pleiotropy (def)

Answer 20

when 1 gene produces multiple phenotypic effects

ex. Alkaptonuria

Question 21

males are more likely than females to inherit a genetic disease if the gene for it is which of the following?

Answer 21

X-linked

men only have 1 X chromosome –> if it’s recessive, it is expressed

women have 2 X chromosomes –> if 1 of them is recessive, the other could still be dominant –> no expression

Question 22

sex-linked traits (def)

Answer 22

are carried on the X or Y chromosome and tend to be inherited by one sex more than the other

Question 23

an individual w/ type AB blood has both blood type alleles IA and IB, and therefore expresses both A and B proteins on the surface of their erythrocytes. Why does this occur?

Answer 23

the alleles are codominant

Question 24

epigenetic effects alter ___

Answer 24

gene expression

Question 25

what happens when red flower + white flower == pink flower?

Answer 25

incomplete dominance

Question 26

what type of inheritance:

2+ genes contribute to a single phenotypic trait

Answer 26

polygenic

Question 27

alkaptonuria is a phenomenon in which 1 gene can have many phenotypic effects. Based on this information, which type of inheritance does alkaptonuria demonstration?

Answer 27

pleiotropy

Question 28

epigenetic effects can alter ___

Answer 28

gene expression – reversibly activating or silencing genes w/o changes in base sequence

Question 29

epigenetic inheritance

Answer 29

we can pass on changes in gene expression to the next generation w/o changes in the structure of the genes themselves

Question 30

epigenetic effects ___

Answer 30

can cause cancer

cause a stem cell to become a liver cell

can cause obesity

Question 31

which term refers to a phenomenon in which 1 gene produces multiple phenotypic effects (i.e. Alkaptonuria)?

Answer 31

pleiotropy

Question 32

epigenetic effects alter

Answer 32

gene expression