Genetics and Inheritance Concepts

These flashcards cover key vocabulary and concepts related to genetics and inheritance, preparing students for their exam.

Dominant Allele

An allele that expresses its phenotype even in the presence of a recessive allele.

Recessive Allele

An allele that only expresses its phenotype when two copies are present.

Diploid Organism

An organism that has two sets of chromosomes, one from each parent.

Incomplete Dominance

A form of inheritance where the phenotype of a heterozygote is intermediate between those of the two homozygotes.

Co-dominance

A condition in which both alleles in a heterozygous individual contribute to the phenotype.

Alleles

Different forms of a gene that can exist for a given trait.

Polygenic Traits

Traits that are controlled by multiple genes, leading to a continuous range of phenotypes.

Pleiotropic Traits

Traits influenced by a single gene that has multiple effects on the phenotype.

Sex-Linked Traits

Traits that are associated with genes located on the sex chromosomes.

Hemizygous

Having only one copy of a gene instead of two; common in X-linked genes in males.

Pedigree Analysis

A diagram that shows the occurrence of a genetic trait across generations.

Linkage

The tendency of genes located close to each other on a chromosome to be inherited together.

Primary Transcript

An initial RNA strand synthesized by transcription; it undergoes processing to become functional mRNA.

Amino Acid Sequence

The order of amino acids in a protein, which determines its structure and function.

Human Genome

The complete set of genetic information for humans, consisting of approximately 3 billion nucleotides.

Transcription

The process where DNA is used to synthesize RNA.

Chromosome

A structure composed of DNA and protein, carrying genetic information.

Polypeptide

A chain of amino acids that folds into a functional protein.

Dominant Phenotype

The physical expression of a dominant allele.

Recessive Phenotype

The physical expression of a recessive allele, seen only when both alleles are recessive.

Mendelian Genetics

The study of the inheritance patterns established by Gregor Mendel.

Dihybrid Cross

A genetic cross involving two traits controlled by different genes.

Gametes

Haploid reproductive cells (sperm and egg) that unite during fertilization.

Homozygous

An organism with two identical alleles for a particular trait.

Heterozygous

An organism with two different alleles for a particular trait.

Phenotypic Ratio

The ratio of different phenotypes produced in a genetic cross.

Genotypic Ratio

The ratio of different genotypes produced in a genetic cross.

X-Chromosome

One of the two sex chromosomes; females have two, while males have one.

Y-Chromosome

The sex chromosome that determines male sex in humans.

Multiple Alleles

A condition in which a gene has more than two alleles.

Mendel's Law of Segregation

The principle that alleles segregate from one another during the formation of gametes.

Mendel's Law of Independent Assortment

Genes for different traits segregate independently of one another.

Blood Type Inheritance

The inheritance of ABO blood groups regulated by multiple alleles.

Genetic Cross

An experiment involving the mating of organisms to study inheritance patterns.

Linkage Disequilibrium

The non-random association of alleles at different loci.

Monohybrids

Organisms that are heterozygous for one particular gene.

F1 Generation

The first filial generation, offspring of the P (parental) generation.

F2 Generation

The second filial generation, produced by interbreeding of F1 individuals.

Allele Frequency

The relative frequency of an allele at a genetic locus in a population.

Autosomes

Chromosomes that are not sex chromosomes.

Dominant Disorder

A genetic disorder that manifests in individuals with just one affected allele.

Recessive Disorder

A genetic disorder that manifests only in individuals with two affected alleles.

Polygenic Inheritance

The inheritance of traits controlled by multiple genes.

Pleiotropic Effects

When one gene influences multiple traits.

Phenotype

The observable characteristics of an organism.

Genotype

The genetic constitution of an organism.

Environmental Influence on Phenotype

The impact of environmental factors on the expression of genes.

Color Blindness

An example of an X-linked recessive disorder affecting male offspring.

Sickle Cell Anemia

A genetic disorder caused by a recessive allele affecting hemoglobin.

Albinism

A recessive genetic condition resulting in a lack of melanin.

Genetic Variation

Differences in DNA sequences among individuals.

Hitchhiker’s Thumb

A trait affected by a recessive allele that allows the little finger to bend.

Tongue Rolling

A trait where the ability to roll one's tongue is inherited as a dominant trait.

Duchenne Muscular Dystrophy

A recessive genetic disorder affecting muscle function.

Alkaptonuria

A recessive disorder leading to black urine from homogentisic acid accumulation.

Cystic Fibrosis

A genetic disorder affecting the lungs, caused by a recessive allele.

Syndrome

A collection of signs and symptoms that occur together.

Autosomal Dominance

When a trait is expressed in individuals with only one copy of the allele.

Branching Diagram

A visual representation of genetic connections and traits in a family.

Crossing Over

The exchange of genetic material between homologous chromosomes during meiosis.

Recombination

The production of offspring with new combinations of traits.