of a cell or organism having two sets of chromosomes or twice the haploid number, abbreviated 2N
containing only one set of chromosomes; half the number of chromosomes as body cells, abbreviated N
Chromosome pairs that are similar in shape and size, centromere position, and staining pattern that possess genes for the same traits. One homologous chromosome is inherited from the organism's father, the other from the mother.
A process in cell division during which the number of chromosomes decreases to half the original number by two divisions of the nucleus, which results in the production of sex cells
A male gamete or sex cell.
A female gamete or sex cell
A type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from the gametes of the two parents.
Process in which homologous chromosomes exchange portions of their chromatids during meiosis. Increases genetic variation
new combination of genetic information in a gamete as a result of crossing over during prophase I of meiosis
An error in meiosis or mitosis in which members of a pair of homologous chromosomes or a pair of sister chromatids fail to separate properly from each other.
Passing of traits from parents to offspring
A characteristic that an organism can pass on to its offspring through its genes.
Branch of biology that studies heredity
A haploid cell such as an egg or sperm. Gametes unite during fertilization to produce a diploid zygote.
Process in sexual reproduction in which male and female reproductive cells join to form a new cell
A one-celled organism formed by the union of a sperm and an egg.
law of segregation
Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete
law of independent assortment
Mendel's law stating that each allele pair segregates independently during gamete formation; applies when genes for two characteristics are located on different pairs of homologous chromosomes. This increases genetic variation.