Grade 11 Biology Quiz: Mendelian Genetics

Instructions:

Choose the correct answer for each question. Each question has one correct answer.

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1. What is the difference between incomplete dominance and codominance?

   • A. Incomplete dominance results in a blend of traits, while codominance results in both traits being expressed simultaneously.
   • B. Incomplete dominance means one trait is completely dominant, while codominance means all traits are recessive.
   • C. Incomplete dominance has no effect on phenotype, while codominance does.
   • D. Incomplete dominance only occurs in plants, while codominance occurs in animals.

2. Which of the following is a summary of Mendel's first law of inheritance?

   • A. The law of independent assortment
   • B. The law of segregation
   • C. The law of dominance
   • D. The law of codominance

3. In a monohybrid cross between a homozygous dominant tall plant (TT) and a homozygous recessive short plant (tt), what is the phenotype of the offspring?

   • A. All tall plants
   • B. All short plants
   • C. 50% tall and 50% short plants
   • D. 25% tall and 75% short plants

4. What are the possible gametes produced from a parent with the genotype AaBb?

   • A. AB, ab, Ab, aB
   • B. AA, Bb, Ab, aB
   • C. Aa, Bb, ab, AB
   • D. AB, Aa, bb, ab

5. What is the phenotypic ratio of a dihybrid cross between two heterozygous parents (AaBb x AaBb)?

   • A. 9:3:3:1
   • B. 1:2:1
   • C. 3:1
   • D. 1:1:1:1

6. Which term describes the genetic makeup of an organism?

   • A. Phenotype
   • B. Genotype
   • C. Allele
   • D. Trait

7. What is the expected genotype ratio from a monohybrid cross between two heterozygous parents (Tt x Tt)?

   • A. 1:2:1
   • B. 3:1
   • C. 2:1
   • D. 1:1

8. If a plant's genotype is homozygous recessive (tt), what is its phenotype?

   • A. Tall
   • B. Short
   • C. Medium
   • D. Variable

9. Which of the following would be considered a dihybrid cross?

   • A. Crossing two plants that are both homozygous dominant
   • B. Crossing two plants with different traits, such as seed shape and seed color
   • C. Crossing a homozygous dominant plant with a homozygous recessive plant
   • D. Crossing two homozygous recessive plants

10. How many different phenotypes can be produced from a cross between two pea plants, one with the genotype TT and the other with genotype Tt?

    • A. 1
    • B. 2
    • C. 3
    • D. 4

11. What does it mean if an organism is said to be heterozygous for a trait?

    • A. It has two identical alleles for a trait.
    • B. It has one dominant and one recessive allele for a trait.
    • C. It has two recessive alleles for a trait.
    • D. It is genetically modified.

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Correct Answers:

1. A
2. B
3. A
4. A
5. A
6. B
7. A
8. B
9. B
10. B
11. B