Chapter 11 Vocab

Question 1

an observable heritable feature

Answer 1

character

Question 2

any detectable variant in a genetic character

Answer 2

trait

Question 3

referring to plants that produce offspring of the same variety when they self-pollinate

Answer 3

true breeding

Question 4

the mating, or crossing, of two true-breeding varieties

Answer 4

hybridization

Question 5

the parent individuals from which offspring are derived in studies of inheritance

Answer 5

P generation

Question 6

the first filial, or hybrid, offspring in a series of genetic crosses

Answer 6

F1 generation

Question 7

offspring resulting from interbreeding of the hybrid F1 generation

Answer 7

F2 generation

Question 8

any of the alternative versions of a gene that produce distinguishable phenotypic traits

Answer 8

allele

Question 9

a gene that is fully expressed in the phenotype of a heterozygote

Answer 9

dominant allele

Question 10

a gene whose phenotypic effect is not observed in a heterozygote

Answer 10

recessive allele

Question 11

states that the two alleles in a pair separate into different gametes during gamete formation

Answer 11

law of segregation

Question 12

a diagram used in the study of inheritance to show the predicted results of random fertilization in genetic crosses

Answer 12

Punnett square

Question 13

having two identical alleles for a given gene

Answer 13

homozygous

Question 14

having two different alleles for a given gene

Answer 14

heterozygous

Question 15

the physical and physiological traits of an organism, which are determined by its genetic makeup

Answer 15

phenotype

Question 16

the genetic makeup, or set of alleles, of an organism

Answer 16

genotype

Question 17

breeding an organism of unknown genotype with a homozygous recessive individual to determine the unknown genotype

Answer 17

testcross

Question 18

an organism that is heterozygous with respect to a single gene of interest

Answer 18

monohybrid

Question 19

an organism that is heterozygous with respect to two genes of interest

Answer 19

dihybrid

Question 20

states that each pair of alleles separates independently of other pairs during gamete formation; applies when genes for two characters are located on different pairs of homologous chromsomes

Answer 20

law of independent assortment

Question 21

the situation in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable

Answer 21

complete dominance

Question 22

the situation in which the phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele

Answer 22

incomplete dominance

Question 23

the situation in which the phenotypes of both alleles are exhibited in the heterozygote because both alleles affect the phenotype in separate, distinguishable ways

Answer 23

codominance

Question 24

a human genetic disease caused by a recessive allele for a dysfunctional enzyme, leading to accumulation of certain lipids in the brain; results in seizures, blindness, and degeneration of motor and mental performance a few months after birth, followed by death within a few years

Answer 24

Tay Sachs disease

Question 25

the ability of a single gene to have multiple effects; Ex: the multiple symptoms associated with certain hereditary diseases such as cystic fibrosis and sickle-cell disease

Answer 25

pleiotropy

Question 26

a type of gene interaction in which one gene alters the phenotypic effects of another gene that is independently inherited

Answer 26

epistasis

Question 27

a heritable feature that varies continuously over a range rather than in an either-or fashion

Answer 27

quantitative character

Question 28

an additive effect of two or more genes on a single phenotypic character; Ex: skin pigmentation in humans

Answer 28

polygenic inheritance

Question 29

the range of phenotypes produced by a single genotype, due to environmental influences

Answer 29

norm of reaction

Question 30

refers to a phenotypic character that is influenced by multiple genes and environmental factors

Answer 30

multifactorial

Question 31

a diagram of a family tree showing the occurrence of heritable characters in parents and offspring over multiple generations

Answer 31

pedigree

Question 32

an individual who is heterozygous at a given genetic locus, with one normal allele and one recessive allele, who can pass on the recessive allele to offspring

Answer 32

carrier

Question 33

a human genetic disorder caused by a recessive allele for a chloride channel protein; characterized by an excessive secretion of mucus and consequent vulnerability to infection; fatal if untreated

Answer 33

cystic fibrosis

Question 34

a human genetic disease caused by a recessive allele, resulting in the substitution of a single amino acid in a globin polypeptide that is part of the hemoglobin protein; characterized by deformed red blood cells that can lead to numerous symptoms

Answer 34

sickle cell disease

Question 35

a human genetic disease caused by a dominant allele, characterized by uncontrollable body movements and degeneration of the nervous system; usually fatal 10 to 20 years after the onset of symptoms

Answer 35

Huntington's disease

Question 36

a technique of prenatal diagnosis in which amniotic fluid, obtained by aspiration from a needle inserted into the uterus, is analyzed to detect certain genetic and congenital defects in the fetus

Answer 36

amniocentesis

Question 37

a technique of prenatal diagnosis in which a small sample of the fetal portion of the placenta is removed and analyzed to detect certain genetic and congenital defects in the fetus

Answer 37

chorionic villus sampling

Question 38

the idea that genetic material contributed "mix" together in a way that blue + yellow make green; predicts that over many generations a freely mating population would give rise to a uniform population of individuals; fails to explain how some traits reappear after skipping a generation; disproved by Gregor Mendel

Answer 38

blending hypothesis

Question 39

the pollen-producing organ of a flower

Answer 39

stamen

Question 40

the egg-bearing organ of a flower

Answer 40

carpel

Question 41

fertilization between different plants

Answer 41

cross pollination

Question 42

a specific place along the length of a chromosome where a given gene is located

Answer 42

locus

Question 43

a cross between individuals that involves one pair of contrasting traits

Answer 43

monohybrid cross

Question 44

a cross between individuals concentrating on two definable traits

Answer 44

dihybrid cross

Question 45

a rule of probability stating that the probability of two or more independent events occurring together can be determined by multiplying their individual probabilities

Answer 45

multiplication rule

Question 46

the probability that any one of two or more mutually exclusive events will occur is calculated by adding together their individual probabilities

Answer 46

addition rule

Question 47

three or more forms of a gene that code for a single trait; Ex: ABO blood group in humans

Answer 47

multiple alleles

Question 48

a form of human dwarfism caused by a single dominant allele; the homozygous condition is lethal

Answer 48

achondroplasia

Question 49

an autosomal recessive hereditary condition characterized by a partial or total lack of melanin pigment, particularly in the eyes, skin, and hair

Answer 49

albinism

Question 50

the analysis of a neonate's blood for metabolic or genetic disorders to prevent mental retardation, disability or death

Answer 50

newborn screening