Genetics and Inheritance - Video

Vocabulary flashcards covering key genetics concepts from the video notes.

Genetics

The study of heredity.

Heredity

The transmission of genetic traits from parents to offspring.

Gene

The basic functional unit of heredity carried on chromosomes; can be replicated, expressed, or mutated.

Chromosome

A structure that carries genes; located in the cell nucleus.

Nucleus

The organelle that houses the cell’s chromosomes.

Protein

A molecule formed by gene expression that helps determine traits.

Mendel

Johann Gregor Mendel, 1822–1884, who used garden peas to study inheritance.

True breeding

Plants that, when self-pertilized, produce offspring identical to the parent.

Hybridization

Crossing true-breeding plants with different traits to produce hybrids.

P generation

Parental generation in a genetic cross.

F1 generation

First filial generation; all offspring from true-breeding parents (hybrids).

F2 generation

Second filial generation; offspring from self-fertilization of F1 hybrids.

Trait

A variation in the physical appearance of a heritable characteristic.

Phenotype

The observable expression of a genotype.

Genotype

The genetic makeup; the alleles an organism carries.

Allele

Variant form of a gene.

Dominant

Allele expressed in the phenotype when present in a heterozygote.

Recessive

Allele whose effects are masked by a dominant allele in a heterozygote.

Homozygous

Two identical alleles for a gene (e.g., WW or ww).

Heterozygous

Two different alleles for a gene (e.g., Ww).

Autosomes

Chromosome pairs 1–22; same appearance in males and females.

Sex chromosomes

Chromosome pair 23; XX in female, XY in male.

Karyotype

Display of chromosomes ordered by size and centromere position.

Sex determination

Biological process determining sex; often by presence of Y; father’s sperm influences sex.

X-linked

Gene located on the X chromosome.

Y-linked

Gene located on the Y chromosome; often related to male development.

Punnett square

Diagram used to predict the genotypes of a cross.

Mendel's Law of Segregation

Alleles segregate into gametes so offspring have an equal chance of inheriting either allele.

Mendel's Law of Dominance

In a heterozygote, the dominant allele is expressed and the recessive allele is hidden.

Codominance

Both alleles are expressed in the phenotype (e.g., AB blood type).

Incomplete dominance

Heterozygote has an intermediate phenotype (e.g., pink from red × white).

Polygenic inheritance

Traits produced by multiple genes; often involves genes on different or same chromosomes.

ABO blood group system

Human blood typing with IA, IB, and i alleles; IA and IB are codominant; multiple alleles at population level.

Hemophilia A

X-linked recessive bleeding disorder; males often affected; females carriers.

Penetrance

Percentage of individuals with a genotype who express the expected phenotype.

Environment and heredity

Environment can influence the expression of genetic traits.

Wild type

Most common allele/phenotype in a population.