CH 14 vocabulary

Question 1

True-breeding

Answer 1

an organism that always passes down certain phenotypic traits to its offspring of many generations.

Question 2

Hybridization

Answer 2

the process of interbreeding between individuals of different species or genetically divergent individuals from the same species.

Question 3

P generation

Answer 3

The first individuals crossed are referred to as the P (parent) generation.

Question 4

F1 Generation

Answer 4

the first filial generation, possesses the information needed to produce both parental phenotypes in the following generation

Question 5

F2 Generation

Answer 5

Produced by the F1 generation, always produces a 3:1 ratio where the dominant trait is present three times as often as the recessive trait.

Question 6

Character

Answer 6

any observable feature, or trait, of an organism, whether acquired from the environment or inherited.

Question 7

Alleles

Answer 7

one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome

Question 8

Dominant allele

Answer 8

the allele that expresses itself at the expense of an alternate allele

Question 9

Recessive allele

Answer 9

an allele whose expression is suppressed in the presence of a dominant allele

Question 10

Law of segregation

Answer 10

during gamete formation each member of the allelic pair separates from the other member to form the genetic constitution of the gamete

Question 11

Punnett square

Answer 11

a graphical representation of the possible genotypes of an offspring arising from a particular cross or breeding event

Question 12

Homozygous

Answer 12

an individual which contains only one allele at the allelic pair

Question 13

Heterozygous

Answer 13

an individual which contains one of each member of the gene pair

Question 14

Genotype

Answer 14

the specific allelic combination for a certain gene or set of genes

Question 15

Phenotype

Answer 15

literally means “the form that is shown”; it is the outward, physical appearance of a particular trait

Question 16

Monohybrids

Answer 16

the offspring of two parents that are homozygous for alternate alleles of a gene pair

Question 17

Monohybrid cross

Answer 17

a cross between parents that differ at a single gene pair (it is NOT the cross of two monohybrids.)

Question 18

Dihybrid

Answer 18

an individual heterozygous for two pairs of alleles

Question 19

Dihybrid cross

Answer 19

a cross between two parents that differ by two pairs of alleles

Question 20

Law of independent assortment

Answer 20

the segregation of the alleles of one allelic pair is independent of the segregation of the alleles of another allelic pair

Question 21

Multiplication rule

Answer 21

the multiplication of the probability of one event by the probability of the other event.

Question 22

Addition rule

Answer 22

the probability of the occurrence of mutually exclusive events is the sum of the probabilities of the individual events.

Question 23

Complete dominance

Answer 23

occurs when one allele of a gene completely masks another.

Question 24

Incomplete dominance

Answer 24

when a dominant allele, or form of a gene, does not completely mask the effects of a recessive allele

Question 25

Codominance

Answer 25

when two different alleles of the same gene are present in a living thing, and both alleles are expressed separately in different parts of an organism.

Question 26

Tay-sachs disease

Answer 26

A rare, inherited disorder that destroys nerve cells in the brain and spinal cord.

Question 27

Epistasis

Answer 27

the interaction between two or more genes to control a single phenotype

Question 28

Polygenic inheritance

Answer 28

a single inherited phenotypic trait that is controlled by two or more different genes.

Question 29

Multifactorial

Answer 29

which means that the trait is influenced by multiple genes as well as being affected by the environment.

Question 30

Pedigree

Answer 30

a diagram that depicts the biological relationships between an organism and its ancestors.

Question 31

Cystic fibrosis

Answer 31

a disease that affects the cells that produce mucus, sweat, and digestive juices. It causes these fluids to become thick and sticky. They then plug up tubes, ducts, and passageways.

Question 32

Sickle-cell disease

Answer 32

a chronic disorder that causes red blood cells contort into a sickle shape. The cells die early, leaving a shortage of healthy red blood cells.

Question 33

Huntington’s disease

Answer 33

An inherited condition in which nerve cells in the brain break down over time.

Question 34

Amniocentesis

Answer 34

The sampling of amniotic fluid using a hollow needle inserted into the uterus, to screen for developmental abnormalities in a fetus.

Question 35

Chorionic villus sampling

Answer 35

a form of prenatal diagnosis to determine chromosomal or genetic disorders in the fetus.