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Genetics
Question | Answer |
---|---|
Gene | A segment of DNA that determines a trait |
Alleles | The different forms of a trait that a gene may have |
Dominant trait | The trait that is expressed, or shown, in the organism; represented by a capital letter. |
Recessive trait | The form of a trait that is hidden or masked; represented by a small letter |
Genotype | The genetic makeup of an organism; represented by a 2-letter code |
Phenotype | The way an organism looks or behaves; determined by its genotype |
Homozygous | An organism with two alleles that are the same. Ex. DD or dd |
Heterozygous | An organism that has two different alleles for a trait. Ex. Dd |
Parent (P1) Generation | The first cross of a genetic study |
Filial (F1) Generation | The offspring, or results, of the parent generation cross |
Probability | The branch of mathematics that is used to predict the chance of something happening |
Punnett Square | A tool used by geneticists to predict the results of a genetic cross |
Purebred | An organism that is homozygous for a trait |
Hybrid | An organism that is heterozygous for a trait |
Genotype ratio | The percentage of organisms with a particular genotype as determined with a Punnett square |
Phenotype ratio | The percentage of organisms with a particular phenotype as determined with a Punnett square |
Monohybrid cross | A genetic study that involves only one gene |
Dihybrid cross | A genetic study that involves two genes. |
RR | Trait: R = red flowers, r = white flowers What is the genotype of a homozygous dominant flower? |
Blue eyes | Trait: B = blue eyes, b = brown eyes What is the phenotype of an organism that is heterozygous? |
tt | Trait: T = 4-toes, t = 3 toes What is the genotype for an organism that is homozygous recessive? |
Ff x Ff | Trait: F = flat leaf, f = curly leaf What is the cross between two heterozygous plants? |
YY x Yy | Trait: Y = yellow bananas, y = green bananas What is the cross between one homozygous dominant banana plant and one heterozygous banana plant? |
ww x Ww | Trait: W = wrinkled seeds, w = smooth seeds What is the cross between a plant that is purebred for smooth seeds and one hybrid plant? |