| A | B |
|---|
| gametes | reproductive cells |
| zygote | fertilized egg |
| multiple alleles | a gene that has three or more alleles |
| polygenic traits | traits that are controlled by a number of genes |
| nondisjunction | the failure of chromosomes to separate properly during one of the stages of meiosis |
| sex-linked | genes that are carried on the X or Y chromosome |
| sex-influenced | a trait taht is caused by a gene whose expression differs in males and females |
| amniocentesis | the removal of a small amount of fluid during the sac surrounding the embryo |
| chorionic villus biopsy | a sample of embryonic cells is removed directly from the membrane surrounding the embryo |
| population sampling | researchers select a small number of individuals that represent the whole population |
| twin studies | used to distuinguish between genetic and environmental influences on specific traits |
| pedigree studies | a family record that shows how a trait is inherited over several generations |
| colorblindness | a recessive sex-linked disorder in which an individual cannot distinguish between certain colors |
| Hemophilia | blood lacks a protein that is essential for clotting |
| sickle cells | clump together, clog the cappilaries, causint great pain, and impairs the flow of oxygen to the body |
| sickle-cell occurs... | primarily in black people |
| Genetic marker | a short section of DNA that indicates the presence of an allele that codes for the trait |
| Klinefelter syndrome | results from the Trisomic genotype XXY resulting in metally retarded and low fertility, and both male and female sex organs |
| Turner Syndrome | a monosomic condition with the genotype XO, and XO female, result: characterised by immature physical development, sterility, and a webbed neck |
| genetic screening | an examination of a person's genetic makeup- involves making a karyotype. |
| karyotype | picture of an individual's chromosome |
| fetoscopy | physician inserts a tiny camera through a small incision in the uterus |
| ultrasound | high frequency sound waves bounce off the fetus, forming an image. Image is called a sonogram. |
| chorion villi sampling | physician analyzes a sample of the chorion villi, which grow betweenthe mother's uterus and placenta |
