Basic Genetics and Inheritance

1. A gene is: A) A type of cell​ B) A type of protein​ C) A segment of DNA that codes for a protein​ D) A chromosomse 2. The eye color of children often resembles their parents. What is genetically passed down from one generation to the next? A) Eye cells​ B) Blood type​ C) Molecules that contain information about eye color​ D) Hormones 3. According to Mendel’s principle of dominance, when an individual carries a dominant and recessive allele: A) Both traits are expressed​ B) The recessive trait is expressed​ C) The dominant trait is expressed in the phenotype​ D) Neither trait is expressed 4. For humans, traits are passed from parent to offspring through the union of: A) Blood cells​ B) Skin cells​ C) Somatic cells​ D) Gamete cells produced by meiosis 5. Two people with normal vision have two sons, one colorblind and one with normal vision. If this couple then has six daughters, what percentage of the daughters would you expect to have normal color vision? A) 0%​ B) 25%​ C) 50%​ D) 100% 6. According to Mendel’s Law of Segregation, in an organism with genotype Aa: A) All gametes have A​ B) All gametes have a​ C) Half of the gametes will have A, half will have a​ D) Gametes will have both A and a 7. A breeder is trying to determine if his brown pigeon is homozygous or heterozygous. He performs a test cross with a white pigeon whose parents were both white. The cross produces four brown and one white offspring. Which statement below is correct? A) The brown pigeon is homozygous dominant​ B) The brown pigeon is heterozygous dominant​ C) The brown pigeon is homozygous recessive​ D) The brown pigeon is codominant 8. Tay Sachs is a recessive genetic disorder. If two parents are heterozygous for Tay Sachs and they have four children, which of the following statements is true? A) Each child has a 50% chance of having Tay Sachs​ B) Each child has a 75% chance of having Tay Sachs​ C) Each child has a 25% chance of having Tay Sachs​ D) All children will have Tay Sachs 9. The scientist who developed the basic principles of genetics is: A) Charles Darwin​ B) Rosalind Franklin​ C) Watson and Crick​ D) Gregor Mendel 10. Hemophilia is a recessive sex-linked trait. If individual I-1 married a person with the same genotype as the individual marked by the arrow (bottom row), what is the chance that they could have a child afflicted with hemophilia? A) 0%​ B) 25%​ C) 50%​ D) 100% 11. What is the correct genotype for individual II-3 on the pedigree below? A) X^h X^h​ B) X^H X^h​ C) X^H X--​ D) X^h Y 12. How many individuals in generation V are carriers (heterozygous) for cystic fibrosis? A) One​ B) Two​ C) Three​ D) Four 13. In corn, purple (P) is dominant to yellow and starchy (S) is dominant to sweet. What type of gametes would a heterozygous purple, sweet plant produce? A) PS, ps​ B) Ps, PS​ C) Ps, ps​ D) pS, ps 14. In a certain bird species, beak lengths vary from small to large with a wide range of different sizes in between. What type of inheritance controls the beak length in the bird population? A) Multiple alleles​ B) Codominance​ C) Incomplete dominance​ D) Polygenic 15. Greg and Olga are concerned about a genetic disorder in their families. Greg’s relatives had a form of muscular dystrophy, which follows an autosomal dominant pattern. What is the probability that Greg can pass the allele for this trait to his children? A) 100%​ B) 75%​ C) 50%​ D) 0% 16. Because the gene for red-green colorblindness is located on the X chromosome, it is normally NOT possible for a: A) Colorblind mother to pass the gene to her son​ B) Colorblind mother to pass the gene to her daughter​ C) Colorblind father to pass the gene on to his son​ D) None of the above