Meiosis and Genetic Inheritance

These flashcards contain key terms and definitions related to meiosis and genetic inheritance, useful for studying concepts and terminology in genetics.

Meiosis

A type of cell division that produces four genetically unique haploid gametes.

Chromosomes

Structures made of DNA and proteins that carry genetic information.

Haploid (n)

A cell with one set of chromosomes (half the normal amount).

Gamete

A sex cell (sperm or egg) that is haploid.

Diploid (2n)

A cell with two sets of chromosomes (one from each parent).

Variation

Differences in traits among individuals in a population.

Homologous chromosomes

A pair of chromosomes with the same genes but possibly different alleles.

Meiosis I

The first division of meiosis where homologous chromosomes separate.

Crossing over (recombination)

Exchange of genetic material between homologous chromosomes during prophase I.

Random assortment

The random distribution of chromosomes into gametes.

Punnett square

A diagram used to predict offspring genotypes and phenotypes.

Fertilization

The fusion of two haploid gametes to form a diploid zygote.

Mendel’s laws

Principles of inheritance: law of segregation and law of independent assortment.

Segregation

Alleles separate during gamete formation.

Independent assortment

Genes for different traits are inherited independently (if unlinked).

Zygote

A fertilized egg; the first diploid cell of a new organism.

Monohybrid cross

A genetic cross involving one trait.

Dihybrid cross

A genetic cross involving two traits.

Sex-linked

A gene located on a sex chromosome (usually X).

Linked genes

Genes close together on the same chromosome that tend to be inherited together.

Map distance / map units

A measure of distance between genes based on recombination frequency (1 map unit = 1% recombination).

Sex-linked traits

Traits determined by genes on sex chromosomes.

Non-nuclear inheritance

Inheritance of genes not found in the nucleus (e.g., mitochondrial DNA).

Maternal inheritance

Traits passed down from the mother through mitochondrial DNA.

Multifactorial model

Traits influenced by multiple genes and environmental factors.

Over-representation

A phenotype appears more often than expected.

Under-representation

A phenotype appears less often than expected.

Nondisjunction

Failure of chromosomes to separate properly during meiosis.