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Heredity 8
Heredity and Evol. 8
| Question | Answer |
|---|---|
| Heredity | Passing of traits to offspring |
| DNA | found in the cell’s nucleus · A molecule : Deoxyribonucleic acid · Genetic material that carries information about an organism from parent to offspring · Information on DNA directs cell functions |
| Gene | A segment of DNA on a chromosome that codes for a specific trait |
| Chromosome | A form of DNA that is condensed or “wound up” · There are many genes on one chromosome · Each chromosome is one strand of DNA . humans have 2 complete sets of 23 chromosomes [46 total] ) |
| Trait | A characteristic that an organism can pass on to its offspring |
| Hybrid or heterozygous | Two different alleles are present for a trait ( Tt) |
| Purebred or Homozygous | Two alleles are the same for a trait ( TT or tt) |
| Allele | The different forms of a gene |
| Dominant allele | An allele whose trait always shows up when it is present in an organism |
| Recessive allele | An allele that is masked when a dominant allele is present |
| Co dominance | the alleles of a gene are neither dominant or recessive · Both traits Cooperate and appear · Written as BW or TbFw · Example: black chicken + white chicken= black and white chicken( BW) |
| Incomplete Dominance | An intermediate phenotype occurs when a heterozygous offspring is produced · A blending of the dominant and recessive trait appears · Written as Bb · Example: black chicken + white chicken= grey chicken |