Term | Definition |
autosome | chromosome that is not a sex chromosome; also called autosomal chromosome |
diploid | term used to refer to a cell that contains two sets of homologous chromosomes |
egg | a sex cell produced by a female |
fertilization | the process in sexual reproduction in which male (sperm) and female (egg) reproductive cells join to form a new cell |
disjunction | the normal separation or moving apart of chromosomes toward opposite poles of the cell during cell division |
gametes | an egg or sperm cell; a sex cell |
haploid/monoploid | refers to a cell that contains only a single set of genes (chromosomes) |
homologous chromosomes | chromosomes where one set comes the male parents and one set comes from the female parent |
karyotype | micrograph of the complete diploid set of chromosomes grouped together in pairs, arranged in order of decreasing size |
meiosis | the process that results in the production of sex cells (sperm and egg) |
oogenesis | production of egg or ovum |
ovum (ova) | the largest cell visible to the naked eye. It is about 0.1 mm in size in humans. Made in the ovary and released into the fallopian tube during ovulation. It is a haploid cell so that when a sperm cell fertilizes it, it forms a diploid zygote |
sexual reproduction | a method of reproduction that involves two parents to produce offspring that are genetically different from either parent |
sex chromosomes | one of two chromosomes that determines an individual’s sex |
spermatogenesis | the process occurring in the male gonad of sexually reproducing organism where the undifferentiated male germ cells develop into spermatocytes which then transform into spermatozoa |
somatic cells | all body cells of an organism, apart from the sperm and egg cells (ex: internal organs, skin, bones, blood, connective tissue); these cells contain a full set of chromosomes whereas reproductive cells contain only half |
synapsis | the pairing of homologous chromosomes during the meiotic phase of cell division |
sperm | male sex cell |
tetrad | structure containing 4 chromatids that forms during meiosis |
zygote | cell that results from the joining of the egg and sperm |
variation | modification in structure, form or function in organism; in genetics it refers to an individual that has characteristics different from the others of the same kind |
crossing over | process during meiosis where homologous chromosomes pair up and exchange segments of their genetic material |
clone | an organism that is genetically identical to the organism from which it was produced |