Free MCQs & Online Quiz Practice for Exams

Q: If both dominant and recessive alleles are present for a given trait the allele expressed will be

A) autosomal

B) dominant

C) somatic

D) recessive

Q: The form of inheritance in which the heterozygous state is expressed as an intermediate is

A) incomplete dominance

B) polygenic inheritance

C) sex-linked inheritance

D) multiple-allele inheritance

Q: A person who inherits the A and the O blood type alleles will possess which blood type

A) A

B) AB

C) B

D) O

Q: Why males tend to inherit more sex-linked characters?

A) There is no corresponding allele on their Y chromosomes

B) There is no corresponding alleles on their X chromosomes

C) They have two X chromosomes

D) They have two Y chromosomes

Q: A permanent change in the genetic structure of a gene is called

A) translocation

B) linkage

C) mutation

D) nondisjunction

Q: Traits that display continuous phenotypic variation are usually determined by this form of inheritance

A) sex-linked inheritance

B) multiple-allele inheritance

C) incomplete dominance

D) polygenic inheritance

Q: Heterozygous individuals that can pass on recessive abnormal conditions even if they do not express the disease are referred to as

A) deleterious donators

B) carriers

C) zygotic

D) phenotypically challenged

Q: Genes that are located on the same chromosome are said to be

A) crossed

B) syncopated

C) linked

D) dominant

Q: In the human blood type AB the alleles are

A) dominant

B) polygenic

C) sex-linked

D) codominant

Q: The universal blood donors for the ABO system are type

A) A

B) B

C) O

D) AB

Q: Heterozygous parents who have had one child with a recessive disease will still have a chance of their second child being born with the same recessive disease

A) 75%

B) 25%

C) 12.5%

D) 50%

Q: Across is made between parents with genotypes AABB and aabb. If there were sixteen offspring how many of them would be expected to exhibit both dominant characteristics?

A) 25%

B) 50%

C) 75%

D) 100%

Q: If a male inherits a sex-linked gene for color blindness__________________

A) It will only be expressed 25%.

B) It will never be expressed

C) It will be expressed only if two copies are present

D) It will always be expressed

Q: Which of the following is not exhibited by DNA double helix?

A) antiparallel configuration

B) complementary base pairing

C) major and minor grooves

D) uracil

Q: If DNA of a particular species was analyzed and it was found that it contains 27% Adenine what would be the percentage of Cytosine?

A) 27%

B) 30%

C) 23%

D) 50%

Q: Hershey and Chase experiments confirmed that DNA was the hereditary material on the basis of the finding that radioactive

A) phage were found in the pellet

B) cells were found in the supernatant

C) sulfur was found inside the cell

D) phosphorus was found in the cell

Q: During proofreading which of the following enzymes reads the DNA?

A) primase

B) topoisomerase

C) DNA ligase

D) DNA polymerase III

Q: UGA UAG and UAA are regarded as

A) complementarity

B) nonsense codons

C) universality

D) initiation codons

Q: Nullisomy can be represented as

A) 2n-2

B) 2n+2

C) 2n-1

D) 2n

Q: Human appendix coccyx and nictitating membrane of the eye are

A) vestigial organs

B) homologous organs

C) analogous organs

D) embryonic organ