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Genetics SB3a.
Intro.to Mendel laws and Meiosis
| Term | Definition |
|---|---|
| Gregor Mendel (III) | A monk in the 1850’s that studied how plants inherit traits |
| crossing over | occurs when genetic material is exchanged between nonsister homologous chromatids |
| diploid | cell with two copies of every chromosome |
| haploid | In the case of a single-celled eukaryotic organism, having a single complete set of chromosomes. In the case of a multicellular eukaryotic organism, having a single complete set of chromosome in each somatic cell |
| gametes | eggs and sperm for sexual reproduction |
| gene | represents the genetic material on a chromosome that contains the instructions for creating a particular trait |
| allele | is one of several varieties of a gene |
| trait | is a distinguishing personal characteristic or quality. |
| locus | refers to the location on a chromosome where a gene is located |
| Meiosis | formation of gametes; a human has 46 chromosomes 23 chromosomes from mom and 23 chromosomes from father (sperm has 23 and egg has 23) |
| law of segregation | refers to the random segregation of alleles (and their chromosomes) to separate gametes |
| law of independent assortment | homologous chromosomes, and the genes they carry, segregate independently of the segregation of other chromosome pairs. |
| multiple alleles | three or more alleles for a particular gene |
| pedigree | a chart that shows the presence or absence of a trait according to the relationships within a family across several generations |
| genetic variability | the process in which homologous chromosomes will exchange genetic material with one another |
| linked genes | genes that reside on the same chromosome and thus cannot segregate independently because they are physically connected. |
| nondisjunction | occurs when the chromosomes do not properly separate |