Biology Chapter 9 Vocab

Question 1

Allele

Answer 1

An alternative version of a gene.

Question 2

Carrier

Answer 2

An individual who is heterozygous for a recessively inherited
disorder and who therefore does not show symptoms of that disorder
but who may pass on the recessive allele to offspring.

Question 3

Character

Answer 3

A heritable feature that varies among individuals within a

population, such as flower color in pea plants or eye color in humans.

Question 4

Dihybrid Cross

Answer 4

An experimental mating of individuals
that are each heterozygous for both of two characters (or the self-pollination
of a plant that is heterozygous for both characters).

Question 5

Dominant Allele

Answer 5

The allele that determines the phenotype

of a gene when the individual is heterozygous for that gene.

Question 6

F1 generation

Answer 6

The offspring of two parental (P generation) individuals;

F1 stands for first filial.

Question 7

F2 Generation

Answer 7

The offspring of the F1 generation; F2 stands for second

filial.

Question 8

Genotype

Answer 8

The genetic makeup of an organism.

Question 9

Heredity

Answer 9

The transmission of traits (inherited features) from one generation
to the next.

Question 10

Heterozygous

Answer 10

Having two different alleles for a

given gene.

Question 11

Homozygous

Answer 11

Having two identical alleles for a given

gene.

Question 12

Hybrid

Answer 12

Offspring that results from the mating of individuals from
two different species or from two true-breeding varieties of the same
species; an offspring of two parents that differ in one or more inherited
traits; an individual that is heterozygous for one or more pairs
of genes.

Question 13

Law of Independent Assortment

Answer 13

A general rule of inheritance (originally
formulated by Gregor Mendel) that when gametes form during
meiosis, each pair of alleles for a particular character segregates
independently of other pairs; also known as Mendel’s second law of
inheritance.

Question 14

Law of Segregation

Answer 14

A general rule in inheritance (originally formulated
by Gregor Mendel) that individuals have two alleles for each
gene and that when gametes form by meiosis, the two alleles separate,
each resulting gamete ending up with only one allele of each gene;
also known as Mendel’s first law of inheritance.

Question 15

Linked Genes

Answer 15

Genes located near each other on the same chromosome

that tend to be inherited together.

Question 16

Locus

Answer 16

The particular site where a gene is found on a chromosome.

Homologous chromosomes have corresponding gene loci

Question 17

Monohybrid Cross

Answer 17

An experimental mating of individuals that are
heterozygous for the character being followed (or the self-pollination
of a heterozygous plant).

Question 18

Mutant

Answer 18

The version of a character that occurs less frequently in nature
than the wild-type

Question 19

P Generation

Answer 19

The parent individuals from which offspring are derived

in studies of inheritance; P stands for parental

Question 20

Phenotype

Answer 20

The expressed traits of an organism.

Question 21

Polygenic Inheritance

Answer 21

The additive effects of two or

more gene loci on a single phenotypic character.

Question 22

Recessive Allele

Answer 22

An allele that has no noticeable effect on the phenotype

of a gene when the individual is heterozygous for that gene.

Question 23

Sex Chromosome

Answer 23

A chromosome that determines whether an individual

is male or female.

Question 24

Sex-linked Gene

Answer 24

A gene located on a sex chromosome. In humans, the

vast majority of sex-linked genes are located on the X chromosome

Question 25

Testcross

Answer 25

The mating between an individual of unknown genotype for
a particular character and an individual that is homozygous recessive
for that same character. The testcross can be used to determine the
unknown genotype (homozygous dominant versus heterozygous).

Question 26

Trait

Answer 26

A variant of a character found within a population, such as purple
or white flowers in pea plants.

Question 27

True-breeding

Answer 27

Referring to organisms for which sexual reproduction
produces offspring with inherited traits identical to those of the
parents. The organisms are homozygous for the characters under
consideration.

Question 28

Wild-type

Answer 28

The version of a character that most commonly occurs in

nature.