1. A white-furred rabbit breeds with a black-furred rabbit and all of their offspring have a phenotype of gray fur. What does the gene for fur color in rabbits appear to be an example of??
a. Incomplete dominance
b. Codominance
c. Mosaicism
d. Complete dominance
Answer: a. Incomplete dominance
2. With regard to the ABO blood group system; if a person of type-B blood has children with a person of type-AB blood, what blood types could their children have?
a. Type-AB, type-A, and type-B
b. Type-AB and type-A
c. Type-A and type-B
d. Type-AB, type-A, and type-B and type-O
Answer: a. Type-AB, type-A, and type-B
3. A cross between AaBB x aaBB yields a genotypic ratio of…?
a. 1 AaBB : 3 aaBB
b. 1 AaBB : 1aaBB
c. 3 AaBB : 1 aaBB
d. All AaBb
Answer: b. 1 AaBB : 1aaBB
4. In a cross between AABB x aabb, the ratio of F2 genotypes between AABB, AaBB, Aabb and aabb would be…?
a. 9 : 3 : 3 : 1
b. 1 : 2 : 2 : 1
c. 2 : 1 : 1 : 2
d. 7 : 5 : 3 : 1
Answer: b. 1 : 2 : 2 : 1
5. If two genes experience independent assortment; which of the following assumption is most likely true??
a. They are located in close proximity on the same chromosome.
b. Crossing over between the genes does not occur
c. The genes are located on different chromosomes or are far apart on the same chromosome
d. The expression of one gene does not affect the expression of the other
Answer: c. The genes are located on different chromosomes or are far apart on the same chromosome
6. In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male?
a. Tortoiseshell females; tortoiseshell males
b. Black females; orange males
c. Tortoiseshell females; black males
d. Orange females; black males
Answer: c. Tortoiseshell females; black males
7. Mendel’s work remained unrecognized from 1865 to 1900. Who were the scientists who rediscovered his work?
a. Francis Crick, James Watson, and Rosalind Franklin
b. Charles Darwin and Herbert Spencer
c. Marie Curie and Irène Curie
d. Hugo DeVries, Carl Correns and Erich von Tschermak
Answer: d. Hugo DeVries, Carl Correns and Erich von Tschermak
Recommended: Genetics Online Practice Test
8. Which of the following U.S. geneticist provided the first conclusive evidence that chromosomes carry the units of inheritance and occur in distinct pairs?
a. Hugo DeVries
b. Edward Tatum
c. George Beadle
d. Walter Sutton
Answer: d. Walter Sutton
9. Who first identified individual genes by studying the giant chromosomes in the salivary gland cells of fruit flies?
a. Theophilus Shickel Painter
b. Charles Atwood Kofoid
c. George Beadle
d. Walter Sutton
Answer: a. Theophilus Shickel Painter
10. In 1944 which American biologist showed that DNA (not proteins) can transform the properties of cells, clarifying the chemical nature of genes?
a. Maclyn McCarty
b. Charles Atwood Kofoid
c. George Beadle
d. Walter Sutton
Answer: a. Maclyn McCarty
11. Which of the following American biologist was one of the first scientists to find that sex is determined by a particular chromosome?
a. Theodor Schwann
b. Charles Atwood Kofoid
c. Nettie Maria Stevens
d. Sylvia Earle
Answer: c. Nettie Maria Stevens
12. Which of the following biologist laid the mathematical foundation of the science of genetics? Hint: also known as the father of genetics.
a. Carl Correns
b. Charles Atwood Kofoid
c. Gregor Mendel
d. Sylvia Earle
Answer: c. Gregor Mendel
13. The innate tendency of an offspring to resemble its parents is known as…?
a. Variation
b. Heredity
c. Inheritance
d. Resemblance
Answer: b. Heredity
14. Choose the correct Genotypic ratio of monohybrid cross:
a. 3:1
b. 1:2:1
c. 2:1:1
d. 9:3:3:1
Answer: b. 1:2:1
15. When a F1 individual is crossed with its either of the two parent; it is known as…?
a. Test cross
b. F1 cross
c. Back cross
d. Monohybrid cross
Answer: c. Back cross
16. Choose the correct statement regarding Mendel’s law of segregation:
a. Genes are separated on different chromosomes.
b. Pairs of alleles separate during mitosis.
c. Pairs of alleles separate during meiosis.
d. Genes are passed from parents to offspring
Answer: c. Pairs of alleles separate during meiosis.
17. Which of the following cross determines the Homozygosity and heterozygosity of an individual?
a. Back cross
b. Self-fertilization
c. Monohybrid cross
d. Test cross
Answer: d. Test cross
18. Linkage is an exception to which of the following Mendel’s laws?
a. Law of Dominance
b. Law of Segregation
c. Law of Independent Assortment
d. None of these
Answer: c. Law of Independent Assortment
19. The phenomenon in which an allele of one gene suppresses the expression of an allele of another gene is known as…?
a. Pseudo-dominance
b. Hypostasis
c. Incomplete dominance
d. Epistasis
Answer: d. Epistasis
20. Choose the correct statement from the following regarding Cystic fibrosis disorder:
a. Sex-linked recessive disorder
b. Autosomal dominant disorder
c. Sex-linked dominant disorder
d. Autosomal recessive disorder
Answer: d. Autosomal recessive disorder
21. The sections of DNA (or RNA) that code for proteins are known as…?
a. Exons
b. Introns
c. Allele
d. Plasmid
Answer: a. Exons
22. Which of the following blood groups are codominant?
a. IA and IB
b. IB and IO
c. IA and IO
d. None of these
Answer: a. IA and IB
23. Which of the following karyotypes is not compatible with survival to birth in humans?
a. 47, XY,+13
b. 47, XX,+18
c. 47, X
d. 45, Y
Answer: d. 45, Y
24. Which disease is caused by a trinucleotide (triplet) repeat expansion?
a. Cystic fibrosis
b. Duchenne muscular dystrophy
c. Huntington disease
d. Osteogenesis imperfecta
Answer: c. Huntington disease
25. A technique used to make exact genetic copies of living things from a single cell is known as…?
a. Sequencing
b. Mapping
c. Cloning
d. Genetic modification
Answer: c. Cloning
26. Consanguinity shows a strong association with which pattern of inheritance?
a. Autosomal dominant
b. Autosomal recessive
c. X-linked dominant
d. X-linked recessive
Answer: b. Autosomal recessive
