Mendel and the Gene Idea

These flashcards cover key vocabulary and concepts from the lecture on Mendelian genetics.

Mendel

A scientist known for discovering the basic principles of heredity through experiments with garden peas.

Allele

A variant form of a gene that can produce different traits, such as purple or white flower color.

Gamete

A reproductive cell that carries one allele for each gene from an organism.

Character

A heritable feature that varies among individuals, such as flower color.

Trait

A variant for a character, such as purple or white color for flowers.

Homozygote

An organism with two identical alleles for a gene.

Heterozygote

An organism with two different alleles for a gene.

Dominant Trait

A trait that is expressed in the phenotype when at least one dominant allele is present.

Recessive Trait

A trait that is only expressed in the phenotype if two recessive alleles are present.

Law of Segregation

The principle stating that the two alleles for a heritable character separate during gamete formation.

Punnett Square

A diagram used to predict the genotype and phenotype combinations in genetic crosses.

Dihybrid Cross

A cross between individuals that deal with two genes, such as seed shape and seed color.

Incomplete Dominance

A genetic situation where one allele does not completely dominate another, resulting in a third phenotype.

Codominance

A genetic scenario wherein both alleles in a heterozygote are fully expressed.

Pleiotropy

A situation where a single gene affects multiple traits.

Epistasis

Interaction between genes where the expression of one gene depends on the presence of one or more 'modifier genes'.

Polygenic Inheritance

A form of inheritance in which multiple genes influence a trait.

Multifactorial Traits

Traits that are influenced by multiple genes and environmental factors.

Pedigree

A family tree representing the inheritance of traits across generations.

Cystic Fibrosis

A genetic disorder caused by a defective chloride transport channel, leading to severe health issues.

Sickle-cell Disease

A genetic condition resulting from a mutation in hemoglobin, leading to characteristic sickle-shaped red blood cells.