Heredity Flashcards

Flashcards covering key vocabulary terms and concepts from a lecture on heredity, including gamete production, genotypes, phenotypes, genetic crosses, modes of inheritance, sex linkage, pedigree charts, and polygenic inheritance.

Gametes

Sex cells formed by meiosis; males produce sperm, females produce ova. They are haploid, meaning they possess one copy of each chromosome.

Diploid Cells

Cells that possess two copies of each chromosome.

Haploid Cells

Cells that possess one copy of each chromosome.

Autosomes

Chromosomes that exist as homologous pairs (maternal and paternal copies) with identical structures and gene sequences at the same loci positions.

Sex Chromosomes

A pair of chromosomes (heterosomes) that determine sex in diploid organisms; they are not homologous and possess different genes.

Alleles

Alternate forms of a gene that typically differ by one or a few bases and can be created via gene mutations.

Genotype

The complete set of alleles that an organism possesses, reflecting the genetic identity of an individual.

Homozygous

If maternal and paternal alleles are the same.

Heterozygous

If maternal and paternal alleles are different.

Hemizygous

Having only one allele for each sex-linked gene (occurs in males).

Phenotype

All of the observable characteristics of an organism, influenced by both genotype and environment, and reflecting the proteins produced.

Epigenetics

Differences in phenotype caused by changes in gene expression rather than changes in the allele sequence.

Complete dominance

One allele is expressed (dominant) over another allele (recessive).

Codominance

Both alleles are autonomously expressed to create a dual phenotype (both present).

Incomplete dominance

Neither allele is completely expressed, resulting in a blended phenotype.

Sex linkage

When a gene is found on a sex chromosome (X or Y), leading to different inheritance patterns based on the sex of the offspring.

Pedigree Chart

A chart of the genetic history of a family over several generations, used to identify the mode of inheritance for a given condition.

Polygenic Inheritance

Characteristics determined by the interaction of multiple genes, exhibiting continuous variation.