Genetics and Mendelian Principles

These flashcards encompass key genetic terms, concepts, and principles from Mendelian genetics, helping to reinforce understanding of inheritance patterns and genetic calculations.

Heredity

The tendency for traits to be passed from parent to offspring.

Mendelian Genetics

The study of heredity pioneered by Gregor Mendel.

True-breeding

Varieties that, when self-fertilized, produce offspring identical to themselves.

Phenotype

The physical expression or traits of an organism.

Genotype

The genetic composition of an individual.

Dominant Trait

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

Recessive Trait

A trait that is only expressed when two recessive alleles are present.

Homozygous

Having two identical alleles for a trait.

Heterozygous

Having two different alleles for a trait.

Allele

Alternative forms of a gene.

Law of Segregation

The two alleles for a heritable character separate during gamete formation.

Independent Assortment

Alleles of genes on nonhomologous chromosomes assort independently during gamete formation.

Punnett Square

A grid used to calculate the genotypes of offspring from parental genotypes.

F1 Generation

The first filial generation from a cross of the parental generation.

F2 Generation

The second filial generation produced from the F1 generation.

Cross-pollination

The transfer of pollen from the flower of one plant to the flower of another.

Gamete

A reproductive cell that contains only one allele for each gene.

Plant Variety

A type of plant that has distinguishable traits.

Mendel's Experimental Design

Mendel studied seven characteristics, each with two distinguishable traits.

3:1 Ratio

The observed phenotypic ratio of dominant to recessive traits in the F2 generation.

Segregation of Traits

The outcome where each parent passes one allele for each trait to their offspring.

Meiosis

The process of cell division that produces gametes.

Allele presence vs Expression

Presence of dominant alleles leads to dominant phenotype expression.

Locus

The specific location of a gene on a chromosome.

Genetic Variation

Differences in allele combinations among individuals.

Seed Shape

Genetic trait controlled by the alleles R (round) and r (wrinkled).

Flower Color

Genetic trait controlled by the alleles P (purple) and p (white).

Environmental Influence

Factors in the environment that affect the expression of traits.

Dihybrid Cross

A cross between two individuals that differ in two traits.

Phenotype Ratio

The ratio of different phenotypes produced in offspring.

Genotype Ratio

The ratio of different genotypes produced in offspring.

Wild Type

The normal or most common phenotype in a population.

Test Cross

Breeding an individual of unknown genotype with a homozygous recessive individual.

Cross between Homozygotes

A genetic cross involving two true-breeding individuals.

Cross between Heterozygotes

A genetic cross involving two individuals with different alleles.

Freckles in Humans

Dominance scenario where freckles (F) dominate over non-freckles (f).

Gamete Formation

The process by which gametes are produced via meiosis.

Mendel's Factors

Now termed genes, governing traits passed to offspring.

Genetic Makeup

The unique set of alleles carried by an individual.

Crossover

The exchange of genetic material between homologous chromosomes during meiosis.

Random Mating

Mating that occurs without specific regard for genotype or phenotype.

Haploid

A cell having a single set of unpaired chromosomes (gametes).

Diploid

A cell containing two complete sets of chromosomes, one from each parent.

Heterozygous Cross

A genetic cross between individuals with different alleles.

Law of Independent Assortment

The law stating that alleles for different traits are distributed to gametes independently.

Genetic Counseling

A service to advise individuals on genetic disorders.

Genetic Screening

Testing done to identify genetic predispositions.

Mendel's Pea Experiments

Studies conducted by Mendel using garden peas to uncover laws of heredity.

F1 Phenotype

The phenotype displayed by the offspring of a cross.

F2 Phenotypes

The observable traits of the second generation offspring.

Genotype Test Example

Determining the genotype of individuals using Punnett squares.

Allele Frequency

The proportion of a specific allele among all alleles for that gene in the population.

Selection Bias

The skewing of results caused by the method of selection of participants.

Backcrossing

Breeding of hybrid offspring with one of the parental genotypes.

False Dominance

When an allele appears dominant due to external factors affecting expression.