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Genetics: Virtual Zygosity (What's a Jamiroquai?) True or False

1. A dominant allele determines a phenotype when present in -> a homozygous individual
2. A haploid individual -> carries only recessive alleles
3. If two genes are NOT linked, how likely are they to be inherited together? -> 50%
4. You identify a single gene affecting three different phenotypes. What is this gene an example of? -> Pleiotropy
5. If a trait is 100% penetrant, it means that -> there is no variation in the trait
6. Examine carefully the pedigree below. Based on the inheritance pattern of this condition, where might its genetic cause reside?


Remember, in pedigrees, men are represented with a square and women with a circle. Roman numerals define generations (I, II, and III), and Arabic numerals (1, 2, and 3) define birth order within each generation. Here, someone carrying the condition has either a filled square or circle. -> Mitochondria

7. When the expression of one gene modifies the expression of a different gene, it is known as -> epistasis
8. Which of the following statements about mutant alleles is incorrect? -> A mutant allele is always recessive.
9. If a true breeding chinchilla rabbit is crossed with a true breeding Himalayan rabbit, all the offspring are chinchilla. What does this information tell you about the relationship between the chinchilla and Himalayan alleles? -> Himalayan is recessive to chinchilla.
10. If the phenotypic ratio of offspring from a cross between a Himalayan rabbit and a chinchilla rabbit is 2 chinchilla : 1 Himalayan: 1 albino, what were the genotypes of the parents? -> cchcch × chch