Biology: Meiosis and Genetics

A set of flashcards covering key vocabulary and concepts from the lecture notes on meiosis and genetics.

Meiosis

A nuclear division that leads to cells with half the original chromosome number.

Nucleotide

The monomer of nucleic acids, consisting of a sugar, phosphate group, and nitrogenous base.

Chromosome

A structure of DNA and proteins that carries hereditary information.

Diploid

Having two of each chromosome (2n).

Haploid

Having one of each chromosome (n).

Gametes

Sex cells that combine in sexual reproduction to restore full chromosome number.

Independent assortment

The random distribution of homologous chromosomes during meiosis.

Crossing over

The exchange of genetic material between homologous chromosomes during meiosis, increasing genetic variation.

Chiasma

The point at which two homologous chromosomes exchange genetic material during crossing over.

Polyploidy

Having more than two of each type of chromosome.

Allele

A version of a gene.

Genotype

The genetic makeup of an individual, represented by alleles.

Phenotype

The physical traits of an individual, often determined by genotype.

Synapsis

The pairing of homologous chromosomes during prophase I of meiosis.

Nondisjunction

The failure of homologous chromosomes to separate properly during meiosis, leading to an abnormal number of chromosomes.

Aneuploidy

An abnormal number of chromosomes resulting from nondisjunction.

Punnett Square

A diagram used to predict the outcome of genetic crosses.

Principle of Segregation

The concept that individuals have two copies of each gene, which segregate during gamete formation.

Principle of Independent Assortment

The principle stating that genes for different traits are inherited independently of each other.

Polygenic inheritance

A trait controlled by two or more genes.

Pleiotropy

A single gene affecting multiple traits.

Codominance

A situation where both alleles in a heterozygote are expressed.

Incomplete dominance

When heterozygotes express an intermediate phenotype.