Term | Definition |
somatic cell | body cells that make up most of your body tissues and organs |
gametes | sex cells, ova, or eggs, in the female, and spermatozoa, or sperm cells, in the male |
homologous chromosomes | two chromosomes, one inherited from the mother and one from the father, that have the same length and general appearance |
atuosomes | chromosomes that contain genes for characteristics not directly related to the sex of an organism |
sex chromosomes | chromosomes that directly control the development of sexual characteristics |
sexual reproduction | involves the fusion of two gametes, resulting in offspring that are a genetic mixture of both parents |
fertilization | actual fusion of an egg and a sperm cell |
haploid | a cell has only one copy of each chromosome |
meiosis | a form of nuclear division that divides a diploid cell into haploid cells |
gametogenesis | the production of gametes |
sperm | the male game that is much smaller than the egg |
egg | the female game that is much bigger than the sperm |
polar bodies | cells with little more than DNA that are eventually broken down |
traits | distinguishing characteristics that are inherited |
genetics | the study of biological inheritance patterns and variation in organisms |
purebred | gentically uniform, or a line of plants that have self-pollinated for long enough |
cross | the mating of two organisms |
law of segregation | two of Mendel's three conclusions or Mendel's first law |
gene | a piece of DNA that provides a set of instructions to a cell to make a certain protein |
allele | any of the alternative forms of a gene that may occur at a specific locus |
homozygous | descrbies two of the same alleles at a specific locus |
heterozygous | describes two different alleles at a specific locus |
genome | all of an organism's genetic material |
genotype | typically refers to the genetic makeup of a specific set of genes |
phenotype | the physical characteristics, or traits, of an individual organism |
dominant allele | the allele that is expressed when two different alleles ro two dominant alleles are present |
recessive allele | the allele that is expressed only when two copies are present |
punnett square | a grid system for predicting all possible genotypes resulting from a cross |
monohybrid corsses | crosses that examine the inheritance of only one specific trait |
testcross | a cross between an organism with an unknown genotype and an organism with the recessive phenotype |
dihybrid crosses | crosses that examine the inheritance of two different traits |
law of independent assortment | Mendel's second law of genetics that states that allele pairs separate independently of each other during gamete formation, or meisosis |
probability | the likelihood that a particular event will happen |
crossing over | the exchange of chromosome segments between homologous chromosomes during prophase 1 of meiosis1 |
genetic linkage | genes located close together ted to be inherited together |