Ch. 14 Vocab

Question 1

any detectable variant in a genetic character

Answer 1

trait

Question 2

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

Answer 2

true-breeding

Question 3

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

Answer 3

hybridization

Question 4

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

Answer 4

alleles

Question 5

Mendel’s first law, stating that the two alleles in a pair segregate into different gametes during gamete formation

Answer 5

law of segregation

Question 6

Mendel’s second law, stating that each pair of alleles segregates, or assorts, independently of each other pair during gamete formation; applies when genes for two characters are located on different pairs of homologous chromosomes

Answer 6

law of independent assortment

Question 7

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

Answer 7

Punnett square

Question 8

an allele that is fully pressed in the phenotype of a heterozygous

Answer 8

dominant allele

Question 9

an allele whose phenotype effect is not observed in a heterozygote

Answer 9

recessive allele

Question 10

having two different alleles for a given gene

Answer 10

heterozygous

Question 11

having two identical alleles for a given gene

Answer 11

homozygous

Question 12

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

Answer 12

genotype

Question 13

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

Answer 13

phenotype

Question 14

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

Answer 14

complete dominance

Question 15

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

Answer 15

incomplete dominance

Question 16

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 16

codominance

Question 17

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

Answer 17

Tay Sachs disease

Question 18

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

Answer 18

epistasis

Question 19

the ability of a single gene to have multiple effects

Answer 19

pleiotropy

Question 20

an additive effect of two or more genes on a single phenotypic character

Answer 20

polygenic inheritance

Question 21

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

Answer 21

multifactorial

Question 22

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

Answer 22

pedigree

Question 23

in genetics, an individual who is heterozygous at a given genetic locus, with one normal allele and one recessive allele

Answer 23

carriers

Question 24

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 24

cystic fibrosis

Question 25

a human genetic disease caused by a recessive allele that results 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

Answer 25

sickle cell disease

Question 26

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

Answer 26

Huntington’s disease

Question 27

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 27

amniocentesis

Question 28

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 28

chorionic villus sampling

Question 29

an observable heritable feature

Answer 29

character