Apologia Biology Module 08 - Vocabulary

Front 1

true breeding

Back 1

if an organism has a certain characteristic that is always passed on to its offspring, we say that this organism bred true with respect to that characteristic

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allele

Back 2

one of a pair of genes that occupies the same position homologous chromosomes

Front 3

genotype

Back 3

two-letter set that represents the alleles an organism possesses for a certain trait

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phenotype

Back 4

the observable expression of an organism's genes

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homozygous genotype

Back 5

a genotype in which both alleles are identical

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heterozygous genotype

Back 6

a genotype with two different alleles

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dominant allele

Back 7

an allele that will determine phenotype if just one is present in the genotype

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recessive allele

Back 8

an allele that will not determine the phenotype unless the genotype is homozygous in that allele

Front 9

Restatement of Mendel's Four Principles

Back 9

1. The traits of an organism are determined by its genes.

2. Each organism has two alleles that make up the genotype for a given trait.

3. In sexual reproduction, each parent contributes ONLY ONE of its alleles to its off-spring.

4. In each genotype, there is a dominant allele. If it exists in an organism, the phenotype is determined by that allele.

Front 10

pedigree

Back 10

a diagram that follows a particular phenotype through several generations

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monohybrid cross

Back 11

a cross between two individuals, concentrating on only one definable trait

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dihybrid cross

Back 12

a cross between two individuals, concentrating on two definable traits

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autosomes

Back 13

chromosomes that do not determine the sex of an individual

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sex chromosomes

Back 14

chromosomes that determine the sex of an individual

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antigen

Back 15

a protein that, when introduced in the blood, triggers the production of an antibody

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autosomal inheritance

Back 16

inheritance of a genetic trait not on a sex chromosome

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genetic disease carrier

Back 17

a person who is heterozygous in a recessive genetic disorder

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sex-linked inheritance

Back 18

inheritance of a genetic trait located on the sex chromosomes

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mutation

Back 19

a radical chemical change in one or more alleles

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change in chromosome structure

Back 20

a situation in which a chromosome loses or gains genes during meiosis

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change in chromosome number

Back 21

a situation in which abnormal cellular events in meiosis lead to either none of a particular chromosome in the gamete or more than one chromosome in the gamete