Mendelian Genetics and Inheritance Patterns

Mendelian Genetics

Study of heredity and trait inheritance.

Traits

Observable characteristics inherited from parents.

Dominant Traits

More common traits expressed with one allele.

Recessive Traits

Traits expressed only with two recessive alleles.

Hybridization

Mating two true-breeding individuals with different traits.

P0 Generation

Parent generation in Mendel's experiments.

F1 Generation

First filial generation from P0 cross.

F2 Generation

Second filial generation from F1 self-fertilization.

Alleles

Alternative versions of a gene causing trait variation.

Law of Segregation

Gene copies separate during meiosis into gametes.

Law of Independent Assortment

Gametes combine independently of their alleles.

True-Breeding Plants

Plants that consistently produce offspring resembling parents.

Continuous Variation

Traits that blend and show a range of phenotypes.

Discontinuous Variation

Distinct traits that remain unchanged across generations.

Mendel's Experiments

Used garden peas for systematic genetic studies.

Self-Fertilization

Process where a plant fertilizes itself naturally.

Phenotype

Observable expression of a genotype in an organism.

Genotype

Genetic makeup of an individual, including alleles.

Mendel's Discoveries

Revealed basic principles of heredity and inheritance.

Quantitative Analyses

Statistical methods used to analyze genetic data.

Scientific Community Rediscovery

Mendel's work revived in 1900 after initial neglect.

Garden Pea Characteristics

Seven traits studied, each with two contrasting forms.

Recessive

Inheritance pattern for certain traits.

Alleles

Different versions of a gene.

Protein Expression

Variation in protein production and activity.

Phenotype

Observable traits expressed by an organism.

Dominant Allele

Allele that expresses its trait in heterozygotes.

Recessive Allele

Allele expressed only in homozygous conditions.

Homozygous Dominant

Two copies of the dominant allele.

Homozygous Recessive

Two copies of the recessive allele.

Heterozygous

One dominant and one recessive allele.

Punnett Square

Tool to predict genetic cross outcomes.

Genotype

Genetic makeup for a specific trait.

Central Dogma

Process: gene → protein → trait.

Incomplete Dominance

Intermediate phenotype in heterozygotes.

Co-dominance

Both alleles expressed equally in phenotype.

Mendelian Genetics

Study of inheritance patterns established by Mendel.

Pleiotropic Genes

Genes affecting multiple traits.

Environmental Influence

External factors altering gene expression.

Dominant Trait Frequency

Not necessarily more common than recessive traits.

Sickle Cell Allele

Depends on context for dominance classification.

Genetic Cross

Mating of organisms to study inheritance.

Mendel's Pea Plants

Classic experiment demonstrating inheritance patterns.

Trait Survival

Frequency influenced by environmental adaptability.

Incomplete Dominance

Neither allele is dominant; both expressed together.

Punnet Square

Tool for predicting genetic trait inheritance.

Super-scripts

Used in Punnet squares to denote alleles.

Homozygous Dominant

Genotype with two dominant alleles (e.g., CRCR).

Homozygous Recessive

Genotype with two recessive alleles (e.g., CWCW).

Heterozygous Genotype

Genotype with one dominant and one recessive allele (e.g., CRCW).

Co-Dominance

Both alleles fully expressed in phenotype.

Multiple Alleles

Single gene with more than two allele options.

Blood Type

Determined by combinations of A, B, AB, O alleles.

Sex-Linked Traits

Traits expressed differently in males and females.

Recessive Allele

Requires two copies for expression in females.

Colorblindness Inheritance

Males inherit colorblindness from their mothers.

Polygenic Trait

Trait influenced by multiple genes.

Continual Variation

Gradual changes between two extremes in traits.

Epigenetics

Study of gene expression modifications without DNA changes.

Gene Expression

Activation or silencing of genes in cells.

Environmental Stimuli

External factors influencing gene expression.

Unique Genetic Combinations

Different gene activations lead to individual uniqueness.

Reversible Epigenetics

Potential to reverse gene expression states.

Cancer and Epigenetics

Diseases may involve abnormal gene expression states.

Gene Specialization

Different cells express different genes for function.

Chemical Modifications

Alterations around genes affecting their activity.

Inheritance of Epigenetics

Some epigenetic changes can be passed to offspring.