FREE USABO Genetics and Cell Biology Questions and Answers

Question 1

In the extracellular matrix of an animal cell, you would like to test the binding partner of integrins in vitro. Integrins would most likely require a firm attachment to which of these options?

Accepted Answer

Actin

Answer

Myosin

Answer

Dynein

Answer

Kinesin

Answer

Cyclin

Question 2

You are working with Dr. Lee at the University of Wisconsin-Madison to investigate cytokinesis in a newly discovered marine worm. You generated antibodies to conserved proteins involved in cell division in another organism to look for proteins that localize to important structures during cell division. What molecular motor protein should you look for in the contractile ring?

Accepted Answer

Myosin

Answer

Actin

Answer

Dynein

Answer

Kinesin

Answer

Cyclin

Question 3

An unnamed acid has a pKa value of 4.76. Which of the following is closest to the ratio of the concentration of its protonated to deprotonated forms in a pH environment of 6.8?

Accepted Answer

1:100

Answer

100:1

Answer

10:1

Answer

1:1

Answer

1:10

Question 4

Which scientist(s) is incorrectly matched with his/her/their discoveries?

Accepted Answer

Frederick Griffith – discovery of transformation through bacteriophages.

Answer

Hershey and Chase – discovery of DNA as the hereditary material of cells.

Answer

Chargaff – discovery that relative amounts of nucleotide bases varies among organisms.

Answer

Watson and Crick – discovery of the double-helix structure of DNA.

Answer

Meselson and Stahl – discovery of the semi-conservative replication of DNA.

Question 5

Which of the following amino-acid substitutions is LEAST likely to be disruptive to protein function?

Accepted Answer

Alanine to valine

Answer

Lysine to glycine

Answer

Cysteine to leucine

Answer

Alanine to proline

Answer

Aspartate to valine

Question 6

Which of the following is incorrect about operons?

Accepted Answer

CAP is an activator of transcription when not bound to cAMP.

Answer

Operons can be switched off with a repressor.

Answer

The lac operon is an inducible operon.

Answer

In the presence of lactose and glucose, the lac operon will not be repressed.

Answer

A mutation in the operator of the trp operon can lead to the overproduction of tryptophan.

Question 7

After Pete was infected with Chikungunya virus, his immune system developed immunoglobulins against the virus’s epitope with a peptide sequence VPRNAELGD. Which of the following mutated sequences will most likely lead to immune evasion? (Assume that the mutated virus retains function)

Accepted Answer

VPRNYELAD

Answer

APRNAELGD

Answer

VPRQAELGD

Answer

VPRNAELAD

Answer

VPRNAEIGD

Question 8

Which process likely explains why exons of the tissue plasminogen activator (TPA) are also found in other proteins?

Accepted Answer

Exon shuffling

Answer

Clonal selection

Answer

Translocation

Answer

Heterochrony

Answer

Transposition

Question 9

Eye color in fruit flies shows an X-linked recessive mode of inheritance with red being the dominant phenotype and white being the recessive phenotype. Which of the following mating experiments best proves this observation?

Accepted Answer

Mate is a white-eye female fly with a red-eye male fly.

Answer

Mate is a heterozygous red-eye female fly with a red-eye male fly.

Answer

Mate is a homozygous red-eye female fly with a white-eye male fly.

Answer

Mate is a white-eye female fly with a white-eye male fly.

Answer

Mate is a heterozygous red-eye female fly with a white-eye male fly.

Question 10

A 30-year-old woman (is planning to have a child and visits a genetic counselor. The only observed genetic disorder in her immediate family is that her brother was afflicted by Hurler syndrome (also known as mucopolysaccharidosis type I), a monogenic, autosomal recessive metabolic disorder caused by a loss of function of a lysosomal enzyme named alpha-L iduronidase. Hurler syndrome manifests itself early in childhood and is often fatal. What is the probability that the woman is a carrier for a disease-causing allele of alpha-L iduronidase?

Accepted Answer

2/3

Answer

¼

Answer

½

Answer

9/16

Answer

¾