Questions on Mendel’s First Law – Law of Segregation
20 multiple-choice questions with five alternatives each about Mendel’s First Law: The Law of Segregation, followed by the answers at the end.
Multiple-Choice Questions: Mendel’s First Law – Law of Segregation
1. What does Mendel’s law of segregation state?
A) Genes for different traits assort independently
B) Alleles separate during gamete formation
C) Traits are inherited only from the mother
D) Only dominant traits are expressed
E) Genes are linked on the same chromosome
2. During which process do alleles segregate according to Mendel’s law?
A) Mitosis
B) Fertilization
C) Meiosis
D) DNA replication
E) Translation
3. According to the law of segregation, each parent contributes how many alleles for a trait to their offspring?
A) Two
B) Four
C) One
D) None
E) Three
4. Mendel’s experiments were primarily conducted on which organism?
A) Fruit flies
B) Pea plants
C) Mice
D) Bacteria
E) Corn
5. What happens to alleles during gamete formation?
A) They combine to form new traits
B) They separate so that each gamete carries only one allele for each gene
C) They replicate multiple times
D) They mutate
E) They remain together
6. If an organism has two different alleles for a trait, it is called:
A) Homozygous
B) Heterozygous
C) Dominant
D) Recessive
E) Polygenic
7. Which of the following best represents the alleles of a heterozygous individual?
A) AA
B) Aa
C) aa
D) A or a
E) None of the above
8. If a pea plant has genotype Aa for seed shape, what alleles will its gametes carry?
A) Both A and a together
B) Only A
C) Only a
D) Either A or a, but not both
E) Neither A nor a
9. In Mendel’s experiments, what was the dominant trait for seed shape?
A) Wrinkled
B) Smooth (round)
C) Yellow
D) Green
E) Tall
10. According to the law of segregation, how many alleles does each gamete receive for a single gene?
A) Two
B) One
C) Three
D) Four
E) None
11. Which phase of meiosis is directly responsible for segregation of alleles?
A) Metaphase II
B) Anaphase I
C) Prophase II
D) Telophase II
E) Interphase
12. What is the expected genotypic ratio in the offspring from a monohybrid cross between two heterozygous parents?
A) 1:1
B) 3:1
C) 1:2:1
D) 2:1
E) 4:0
13. What does the phenotype refer to?
A) The genetic makeup of an organism
B) The observable physical traits of an organism
C) The gametes produced by an organism
D) The dominant allele only
E) The recessive allele only
14. If two homozygous parents (AA and aa) are crossed, what will be the genotype of the offspring?
A) AA
B) aa
C) Aa
D) Aa and aa
E) AA and Aa
15. How does the law of segregation relate to genetic diversity?
A) It decreases genetic variation
B) It causes alleles to duplicate
C) It ensures alleles separate randomly into gametes, increasing diversity
D) It causes only dominant traits to be passed on
E) It fixes alleles in the population
16. Which term describes two alleles that are the same for a particular gene?
A) Heterozygous
B) Homozygous
C) Dominant
D) Recessive
E) Polygenic
17. What would be the gametes produced by an organism with genotype AaBb, considering independent assortment and segregation?
A) AB only
B) Ab only
C) aB only
D) AB, Ab, aB, ab
E) Aa, Bb
18. Which of these is NOT a conclusion from Mendel’s law of segregation?
A) Alleles segregate so each gamete receives only one
B) Traits are inherited as discrete units
C) Alleles blend to form intermediate traits
D) Segregation occurs during gamete formation
E) Dominant alleles mask recessive ones
19. What is the significance of Mendel’s law of segregation in modern genetics?
A) It explains linkage of genes
B) It describes how traits are blended
C) It forms the basis of understanding how traits are inherited independently
D) It explains DNA replication
E) It refutes the existence of alleles
20. If a parent with genotype Aa produces gametes, what is the probability that a gamete will carry the “a” allele?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%
Answer Key
1. B
2. C
3. C
4. B
5. B
6. B
7. B
8. D
9. B
10. B
11. B
12. C
13. B
14. C
15. C
16. B
17. D
18. C
19. C
20. C
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