| A | B |
|---|
| pedigree | a graphic representation of genetic inheritance. |
| carrier | a half-shaded circle or square that represents a heterozygous individual |
| examples of simple recessive disorders | cystic fibrosis, tay-sachs disease, phenylketonuria |
| example of simple dominant heredity | cleft chin, hanging earlobes, Huntington's disease |
| transposons | jumping genes |
| incomplete dominance | the phenotype of heterozygous individuals is intermediate between those of the two homozygotes |
| codominance | expression of both alleles |
| multiple alleles | traits controlled by more than two alleles, even though only two alleles of a gene can exist within an individual |
| autosomes | the 22 pairs of homologous chromosomes |
| sex chromosomes | these are the two chromsomes, which determine the sex of an individual |
| sex-linked traits | traits controlled by genes located on the sex chromosomes |
| examples of sex-linked traits | colorblindness, hemophilia |
| polygenic inheritance | the inheritnce pattern of a trait that is controlled by two or more genes |
| examples of multiple allele | blood types |
| examples of polgenic inheritance | height, weight, shape, skin color |
| the 2 types of environmental influences on genes | external and internal environments |
| Example of codominance in humans | sickle cell anemia |
| sickle-celled anemia | a condition in which the gene for hemoglobin produces a protein that is different by one amino acid. This hemoglobin cyrstalizes when oxygen levels are low, changing the red blood cells into a sickle shape |
| the only autosomal trisomy in which affected individuals survive to adulthood | Trisomy 21 or Down syndrome |
| trisomy | a condition that is usually results from nondisjunction and causes individuals to have a extra chromosome or part of an extra chromosome |
| karyotype | a chart or picture of of chromosome pairs |
