Chapter 10 Flashcards
Genetic Variation
Demonstrated by the differences in appearance that offspring show from parents and siblings.
Genes
The units of heredity made up of segments of DNA.
Gametes
Reproductive cells (sperm and eggs) by which genes are passed to the next generation.
Somatic Cells
The cells of the body except for gametes. Contain 46 chromosomes.
Locus
The specific position of each gene on a certain chromosome.
Asexual Reproduction
A single individual passes genes to its offspring without the fusion of gametes.
Sexual Reproduction
Two parents give rise to offspring that have unique combinations of genes inherited from the two parents.
Karyotype
An ordered display of the pairs of chromosomes from a cell.
Homologous Pair
Chromosomes with same length and shape that carry genes controlling the same inherited characters.
Sex Chromosomes
Determine the sex of the individual, X and Y. Human females have a homologous pair of X chromosomes (XX). Human males have one X and one Y chromosome.
Autosomes
The remaining 22 pairs of chromosomes other than the sex chromosomes.
Diploid Cell
Has two sets of chromosomes (2n). For humans, the diploid number is 46 (2n = 46).
Haploid
A cell that contains a single set of chromosomes such as a gamete. (n) For humans, the haploid number is 23 (n = 23).
Zygote
The fertilized egg, has one set of chromosomes from each parent and so is diploid.
Meiosis
A type of cell division which results in cells that only have half the usual number of chromosomes, one from each pair. Four new haploid cells are produced.
