Genetic Terms and Mendel's Laws

Vocabulary terms and definitions related to basic genetics and Gregor Mendel's pea plant experiments as outlined in the lecture notes.

Gene

A section of DNA that codes for a particular protein, providing specific genetic information and coding for a particular trait or characteristic.

Allele

A different version or form of a gene that codes for a different version of a characteristic.

Genotype

The allele pair for each characteristic; a description of the pair of alleles present for a characteristic.

Phenotype

The physical expression of an allele pair.

Homozygous

A pair of alleles that are the same, producing a characteristic such as $HH$ or $rr$.

Heterozygous

A pair of alleles that are different, producing a characteristic such as $Hh$ or $Rr$.

Dominant Allele

An allele that will always be expressed even when there is only one present, represented by a capital letter.

Recessive Allele

An allele that will only be expressed when both alleles are of this type, represented by the corresponding small letter.

Homologous pairs

Pairs of chromosomes where each chromosome in the pair carries genes for the same characteristic.

Autosomes

The 22 pairs of homologous chromosomes in humans that are not involved in determining gender.

Sex chromosomes

The last pair of chromosomes ($X$ and $Y$) that determine the gender of an individual.

Genetics

The study of inherited characteristics.

Gregor Mendel

An Austrian monk who conducted experiments on pea plants and concluded that features are controlled by factors (genes) that come in pairs.

F1 Generation

The first generation of offspring, often hybrids; in Mendel's experiment, crossing pure red with white resulted in only red flowered plants.

F2 Generation

The second generation of offspring produced by self-crossing the F1 generation; in Mendel's experiment, this resulted in $\frac{3}{4}$ red and $\frac{1}{4}$ white plants.

Pure breeding

Plants that only produce flowers with the same color as the parent generation, indicating a homozygous genotype.