Biology 120 Notes - CH. 13: Meiosis

Flashcards based on the key terms and concepts from Chapter 13 on Meiosis in Biology 120.

gametes

Reproductive cells, such as egg and sperm, that combine during fertilization.

meiosis

A type of nuclear division that results in halving the number of chromosomes.

karyotype

A visual representation of all chromosomes in a human cell, showing their number and structure.

autosomes

Non-sex chromosomes that are not involved in determining the sex of an organism.

homologous chromosomes

Pairs of chromosomes that have the same genes at the same loci but may have different alleles.

ploidy

The number of sets of chromosomes in a cell; diploid (2n) means two homologs of each chromosome.

haploid number (n)

Indicates the number of sets of chromosomes, with humans having 2n.

zygote

The diploid (2n) cell formed by the fertilization of an egg and sperm.

gametogenesis

The process through which daughter cells develop into gametes (egg or sperm).

crossing-over

The exchange of genetic material between homologous chromosomes during synapsis.

chiasmata

The points where homologous chromosomes crossover to exchange genetic information.

cytokinesis

The process that follows telophase where the cell divides into two daughter cells.

natural selection

A mechanism of evolution where individuals with advantageous traits are more likely to survive and reproduce.

adaptations

Heritable variations that improve an organism's chances of survival and reproduction.

down syndrome

A genetic disorder resulting from an extra chromosome 21, leading to trisomy.

purifying selection

Natural selection that acts against deleterious alleles, reducing their prevalence in a population.