Key Genetic Terms Quiz

Key Genetic Terms

• Alleles: Different forms of a gene for a particular trait
• Heterozygous: An organism that has two different alleles for a particular trait
• Homozygous: An organism that has two identical alleles for a particular trait
• Gregor Mendel: Independent assortment; genes for different traits separate independently, each gamete carries one allele for each gene
• Incomplete dominance: Heterozygous phenotype is between the two homozygous phenotypes (e.g., red + white = pink)
• Polygenic traits: One gene impacts a characteristic (e.g., human skin color)
• Codominant alleles: Both alleles expressed in heterozygous individuals (e.g., blood type AB)
• Diploid (2N): A cell or organism that has two sets of chromosomes. One set from each parent.
• Haploid (N): Half set of chromosomes, one of each in gametes (e.g., human egg or sperm)
• Linked genes: Genes on the same chromosome
• Gene maps: Based on the frequency of crossing over; more of ten genes crossing over more they are on the chromosome
• Probability: Likelihood of an outcome (e.g., 50:50 chance of flipping heads or tails)
• Sex-linked genes: A gene located on a sex chromosome (X or Y)
• Pedigrees: Family tree on genetic traits (○ is female, □ is male).
• Dominant allele: Expressed after heterozygous or homozygous (uppercase)
• Recessive allele: Only expressed when homozygous recessive (lowercase)
• Nondisjunction: Failure of chromosomes to separate during meiosis.