1. The most likely explanation for the fact that the human genome
consists of 3.2 billion bases, and encodes about 20,325 proteins, is that:
A. All of the genome encodes protein.
B. The genome includes many copies of the instructions for each type of
protein.
C. Amino acids encode DNA sequences.
D. Much of the genome does not encode protein.
E. Each protein is encoded by about 160,000 DNA bases.
2. DNA replication is necessary so that:
A. Transcription can proceed.
B. Translation can proceed.
C. Genetic information is not lost as the information in DNA sequences
is accessed.
D. The cell does not die when it divides.
E. The cell can grow.
3. Cells replicate DNA:
A. During the M phase of the cell cycle.
B. All the time.
C. During the S phase of the cell cycle.
D. Only when a person is stressed.
E. More frequently the older a person gets.
4. During transcription :
A. Protein is synthesized from DNA.
B. DNA is replicated.
C. RNA is synthesized from protein.
D. RNA is synthesized from DNA.
E. Protein is synthesized from amino acids.
5. To express a gene, DNA is first transcribed into a corresponding
strand of:
A. mtDNA.
B. rRNA.
C. mRNA.
D. tRNA.
6. The nitrogenous base that is in RNA but not in DNA is:
A. Thymine.
B. Thiamine.
C. Uracil.
D. Urea.
E. Adenine.
7. RNA differs from DNA in that:
A. Most of it is single-stranded.
B. It is usually double-stranded.
C. It has thymine instead of uracil.
D. It has deoxyribose instead of ribose.
E. It encodes information but has no other functions.
8. In a bacterial cell, the three genes of the lactose operon are:
A. Expressed continuously.
B. Expressed only when lactose is absent.
C. Expressed when lactose synthesis is required.
D. Expressed only in the presence of lactose.
E. Never expressed, because they are pseudogenes.
9. Transcription factors function in the expression of genes by:
A. Initiating transcription.
B. Associating to initiate translation.
C. Turning transcription of specific genes on or off.
D. Halting the activity of RNA polymerase at the end of transcription.
E. Bringing amino acids into the ribosome.
10. Parts of an mRNA molecule that are removed before protein synthesis
are called:
A. Interims.
B. Exons.
C. Exomes.
D. Promoters.
E. Introns.
11. A(n) _______ carries a specific amino acid to a ribosome, where the
amino acid bonds to another.
A. mtDNA
B. rRNA
C. mRNA
D. tRNA
E. siRNA
12. Ribosomal RNAs:
A. Are translated from DNA.
B. Are synthesized by ribosomes.
C. Connect codons to amino acids.
D. Complex with proteins to form ribosomes.
E. Are made from amino acid subunits.
13. The group of organelles
including the endoplasmic reticulum, the Golgi complex, endosomes, lysosomes
and vacuoles are known collectively as the _________.
A. Cytoplasmic system.
B. Endoplasmic system.
C. Endomembrane system.
D. Endomorphic system.
E. Plasmomembrane system.
14. What word describes the
synthesis and secretion of a substance from the cell in a continual,
unregulated manner?
A. Constitutive.
B. Regulated.
C. Conditional.
D. Constantive.
E. Regulative.
15. In general, how are proteins
targeted to specific destinations?
A. Sorting signals located on the gene.
B. Sorting signals located on the proteins.
C. Receptors in transport vesicle walls that recognize them.
D. Sorting signals on the cellular ribosomes.
E. Both sorting signals located on the proteins and receptors in
transport vesicle walls that recognize them.
16. A tissue has been briefly labeled with radiolabeled amino
acids. It is then transferred to a
medium containing unlabeled amino acids.
This can be done several times with different tissue samples for varying
periods of time. What is the transfer to
the medium containing unlabeled amino acids called?
A. Chase.
B. Pulse.
C. Pulse-chase.
D. Labelard.
E. Statin.
17. A mutant that functions
normally at reduced temperature, but not at elevated temperatures is called a ______
mutant.
A. Restrictive.
B. Permissive.
C. Temperature-sensitive.
D. Frame-shift.
E. Point.
18. Reduced temperatures at
which temperature-sensitive mutants function normally are called ______
temperatures.
A. Restrictive.
B. Permissive.
C. Temperature-sensitive.
D. Frame-shift.
E. Point.
19. Smooth microsomes are
derived from the ______; rough microsomes are derived from the _______.
A. Golgi complex, RER.
B. SER, RER.
C. Mitochondria, RER.
D. RER, Golgi complex.
E. Golgi complex, RER and SER, RER.
20. What is the effect on a
yeast cell of the presence of a mutant gene responsible for vesicle formation
at the ER membrane?
A. The ER shrinks.
B. The Golgi complex expands greatly.
C. Cells accumulate expanded ER cisternae.
D. Cells amass an excess number of unfused vesicles.
E. The nucleus becomes swollen.
21. Which type of cells below is
known for its extensively developed SER?
A. Skeletal muscle cells.
B. Kidney tubule cells.
C. Steroid-producing endocrine cells.
D. Skin cells.
E. Skeletal muscle cells, kidney tubule cells and steroid-producing
endocrine cells.
22. Which of the following is
not included within the nucleus of a typical interphase (nonmitotic) cell?
A. Chromosomes.
B. Nuclear matrix.
C. Nucleolus.
D. Nucleoplasm.
E. Lamellae.
23. With what is the space
between the two membranes of the nuclear envelope continuous?
A. The spindle.
B. The entire Golgi complex.
C. The ribosomes.
D. The ER lumen.
E. The chromosomes.
24. What is the general name of
the approximately 30 proteins that comprise the nuclear pore complex?
A. Porins.
B. Nucleorins.
C. Nucleoporins.
D. Complexins.
E. Connexins.
25. What group of proteins
associated with DNA could be described as many widely diverse structural,
enzymatic and regulatory proteins?
A. Histones.
B. Nonhistone proteins.
C. Acidic proteins.
D. DNA helicase.
E. DNA polymerase.
