Module 4 - The Principle of Genetics

Question 1

idea that genetic material from 2 parents blend together (ex. blue and yellow paint make green)

Answer 1

blending hypothesis

Question 2

idea that parents pass on discrete heritable units (genes)

Answer 2

particulate hypothesis

Question 3

heritable feature that varies among individuals

Answer 3

character

Question 4

each variant for a character, such as purple or white for flowers

Answer 4

trait

Question 5

Mendel mated 2 contrasting, true-breeding varieties

Answer 5

hybridization

Question 6

true-breeding parents

Answer 6

P generation

Question 7

hybrid offspring of the P generation (hybrids)

Answer 7

F1 generation

Question 8

produced when F1 individuals self-pollinate or cross-pollinate with other F1 hybrids

Answer 8

F2 generation

Question 9

what Mendel called a “heritable factor” is what we now called a

Answer 9

gene

Question 10

used to show possible combinations of sperm and egg

Answer 10

punnet square

Question 11

organism with two identical alleles for a character

Answer 11

homozygous

Question 12

organism that has 2 different alleles for the gene controlling that character

Answer 12

heterozygous

Question 13

T/F- an organism’s traits do not always reveal its genetic composition due to the different effects of dominant and recessive alleles

Answer 13

true

Question 14

refers to the physical appearance

Answer 14

phenotype

Question 15

refers to the genetic makeup

Answer 15

genotype

Question 16

a cross between heterozygotes following one character

Answer 16

monohybrid cross

Question 17

describes the segregation of alleles from different genes into gametes

Answer 17

law of independent assortment

Question 18

cross between F1 dihybrids

Answer 18

dihybrid cross

Question 19

describes the segregation of alleles within one gene into gametes

Answer 19

law of segregation

Question 20

occurs when phenotypes of the heterozygote and dominant homozygote are identical (dominant allele completely masks the recessive one)

Answer 20

complete dominance

Question 21

the phenotype of F1 hybrids is somewhere between the phenotypes of the 2 parental varieties (neither allele is dominant)

Answer 21

incomplete dominance

Question 22

two dominant alleles affect the phenotype in separate, distinguishable ways (both alleles are dominant)

Answer 22

codominance

Question 23

T/F - dominant alleles are more common in populations than recessive ones

Answer 23

false

Question 24

a property where most genes have multiple phenotypic effects

Answer 24

pleiotropy

Question 25

occurs when a gene at one locus alters the phenotypic expression of a gene at a second locus

Answer 25

epistasis

Question 26

an addictive effect of two or more genes on a single phenotype

Answer 26

polygenic inheritance

Question 27

T/F - many human traits follow Mendelian patterns of inheritance

Answer 27

true

Question 28

a family tree that describes the interrelationships of parents and children across generations

Answer 28

pedigree

Question 29

are heterozygous individuals who carry the recessive allele but are phenotypically normal

Answer 29

carriers

Question 30

a recessive condition characterized by a lack of pigmentation in skin and hair

Answer 30

albinism

Question 31

T/F - dominant alleles that cause a lethal disease are rare and arise by mutation

Answer 31

true

Question 32

a form of dwarfism caused by a rare dominant allele

Answer 32

archondroplasia

Question 33

a gene that is located on either sex chromosome is called a

Answer 33

sex-linked gene

Question 34

T/F - x-linked recessive disorders are much more common in females than in males

Answer 34

false

Question 35

genes located on the same chromosome that tend to be inherited together

Answer 35

linked genes

Question 36

offspring with a phenotype matching one of the parental phenotypes

Answer 36

parental types

Question 37

offspring with non parental phenotypes (nee combination of traits)

Answer 37

recombinant types/ recombinants

Question 38

T/F - higher than 50% frequency of parental types means that the genes are linked

Answer 38

true

Question 39

results from the fertilization of gametes in which nondisjunction occured

Answer 39

aneuploidy

Question 40

a breakage of chromosome can lead to 4 types of changes in chromosome structure

Answer 40

1. deletion 2. duplication 3. inversion 4. translocation

Question 41

an aneuploid condition that results from 3 copies of chromosome 21

Answer 41

down syndrome (trisomy 21)

Question 42

result of an extra chromosome in male, producing XXY individuals

Answer 42

klinefelter syndrome

Question 43

produces X0 females who are sterile; only known viable monosomy in humans

Answer 43

monosomy X (turner syndrome)

Question 44

results from a specific deletion in chromosome 5

Answer 44

cri du chat ("cry of the cat")

Question 45

cancers that are caused by translocations of chromosomes

Answer 45

chronic myelogenous leukemia (CML)