GRE Cell and Molecular Biology Practice MCQs Test Paper

GRE Cell and Molecular Biology MCQs Tests

1. The primary action of steroid hormones is at the level of

(A) RNA export from the nucleus

(B) transcription

(D) mRNA degradation

(E) gene rearrangement

2. The first metabolic intermediate that is common to the aerobic metabolism of glucose and fatty acids is

(A) acetyl CoA

(B) beta-hydroxybutyrate

(D) citrate

(E) glyceraldehyde 3-phosphate

3. In an operon regulated only by attenuation, a mutation causing oversynthesis of the gene

products is most likely to be in the part of the DNA corresponding to the

(A) operator

(B) 3′terminal sequence of the RNA

(C) 5′terminal sequence of the RNA

(D) introns of the RNA

(E) coding sequence for the transactivator

4. Two protein sequences are compared by BLAST and produce an e value of e−100. This e value most

likely signifies which of the following about the genes encoding these two proteins?

(A) They function in the same tissue.

(B) They have unrelated functions.

(C) They are descended from a common ancestor.

(D) They are derived from related species.

(E) They encode proteins that form a dimeric complex.

5. Which of the following groups of enzymes are unique to the Calvin cycle?

(A) Ribulose bisphosphate carboxylase, phosphoribulokinase, and sedoheptulose 1,7-bisphosphatase

(B) Ribose 5-phosphate isomerase, epimerase, and aldolase

(D) Phosphoglycolate phosphatase, glycerol kinase, and serine synthetase

(E) Sucrose synthase, hexokinase, and glucose 6-phosphate dehydrogenase

6. Which of the following best describes the hyperchromicity of DNA?

(A) The shift in UV absorbance to longer wavelengths upon denaturation

(B) The shift in UV absorbance to shorter wavelengths upon hydrolysis

(D) The increase in absorbance at 260 nm upon annealing

(E) The increase in absorbance at 260 nm upon denaturation

7. Isopentenyl pyrophosphate is a precursor of which of the following?

I. Cholesterol

II. Farnesyl groups on proteins

III. Steroid hormones

(A) I only

(B) I and II only

(D) II and III only

(E) I, II, and III

8. Cytokinesis in animal cells is caused by

(A) the sliding movements of a band of

microtubules around the circumference of the cell

(B) the contraction of a band of actin filaments around the circumference of the cell

(D) endocytosis of the plasma membrane around the equator of the cell

(E) fusion of cytoplasmic membrane vesicles at the equator of the cell

9. The synthesis of mRNA’s that encode the proteins of eukaryotic ribosomes occurs in the

(A) cytoplasm

(B) nuclear envelope

(D) euchromatin

(E) heterochromatin

10. Which of the following is NOT a consequence of increased cellular levels of cAMP?

(A) Activation of a kinase cascade

(B) Activation of the transducin G-protein

(D) Inhibition of glycogen synthesis

(E) Dissociation of the cAMP-dependent protein kinase tetramer