Unit 1 - q&a

Question 1

Which statement about microRNAs (miRNAs) is correct?

Answer 1

miRNAs are formed in the cytoplasm and repress
translation or promote degradation of messenger
RNA (mRNA) before it can be translated

The miRNAs are formed in the cytoplasm from
pre-miRNAs and processed by the enzyme dicer that
ultimately assembles RNA-induced silencing complex, which then generates miRNAs. The miRNAs regulate gene expression by binding to the complementary region of the RNA and repressing translation or promoting degradation of messenger RNA before it can be translated by the ribosome.

Question 2

Compared with the intracellular fluid, the extracellular fluid has
__________ sodium ion concentration,
__________ potassium ion concentration,
__________ chloride ion concentration, and
__________ phosphate ion concentration

Answer 2

Higher, lower, higher, lower

Question 3

In comparing two types of cells from the same person, the variation in the proteins expressed by each cell type reflects which of the following?

Answer 3

Cell-specific expression and repression of specific
genes

Question 4

telomeres in cancer cells:

Answer 4

In cancer cells, telomerase activity is usually reduced compared with normal cells

Question 5

telomers are:

Answer 5

Telomeres are repetitive nucleotide sequences at
the end of a chromatid

Telomeres serve as protective caps that prevent the
chromosome from deterioration during cell division

Telomeres are gradually consumed during repeated
cell divisions

Question 6

Which of the following events does not occur during
the process of mitosis?

Answer 6

Replication of the genome

Question 7

The term “glycocalyx” refers to what?

Answer 7

The negatively charged carbohydrate layer on the
outer cell surface

Question 8

Which statement is incorrect?

Answer 8

In most diseases, homeostatic mechanisms are no
longer operating in the body

Question 9

what subcellular site is deficient or mutant protein

The abnormal cleavage of mannose residues during the post-translational processing of glycoproteins results in the development of a lupus-like autoimmune disease in mice. The abnormal cleavage is due to a mutation of the enzyme α-mannosidase II.

Answer 9

Golgi apparatus

Question 10

what subcellular site is deficient or mutant protein

The observation that abnormal cleavage of mannose
residues from glycoproteins causes an autoimmune
disease in mice supports the role of this structure in
the normal immune response.

Answer 10

Glycocalyx

Question 11

what subcellular site is deficient or mutant protein

Studies completed on a 5-year-old boy show an accumulation of cholesteryl esters and triglycerides in his liver, spleen, and intestines and calcification of both adrenal glands. Additional studies indicate the cause to be a deficiency in acid lipase A activity.

Answer 11

Lysosomes

Question 12

cellular location of Protein condensation and packaging

Answer 12

Golgi apparatus

Question 13

cellular location of Initiation of translation

Answer 13

Cytosol

Question 14

cellular location of Gene transcription

Answer 14

Nucleus

Question 15

Worn-out organelles are transferred to lysosomes by
which of the following?

Answer 15

Autophagosomes - double membrane structures called formed in the cytosol.

Question 16

Which of the following is not a major function of the
endoplasmic reticulum (ER)?

Answer 16

Secretion of proteins synthesized in the cell

Question 17

Which of the following does not play a direct role in the process of transcription?

Answer 17

Helicase

Question 18

Which statement is true for both pinocytosis and
phagocytosis?

Answer 18

Involves the recruitment of actin filaments

Question 19

Which of the following proteins is most likely to be the product of a proto-oncogene?

Answer 19

Growth factor receptor

Question 20

Which statement is incorrect about oncogenes

Answer 20

Inactivation of anti-oncogenes protects against the
development of cancer

Question 21

Which statement about feedback control systems is incorrect?

Answer 21

Positive feedback usually promotes stability in a
system

Question 22

Assume that excess blood is transfused into a patient
whose arterial baroreceptors are nonfunctional and
whose blood pressure increases from 100 to 150 mm
Hg. Then, assume that the same volume of blood is infused into the same patient under conditions in which his arterial baroreceptors are functioning normally and blood pressure increases from 100 to 125 mm Hg.

What is the approximate feedback “gain” of the arterial baroreceptors in this patient when they are functioning normally?

Answer 22

−1.0

Question 23

Which of the following cell organelles is responsible for producing adenosine triphosphate (ATP), the energy Currency of the cell?

Answer 23

Mitochondria

Question 24

Which statement about mRNA is correct?

Answer 24

mRNA carries the genetic code to the cytoplasm

Question 25

“Redundancy” or “degeneration” of the genetic code
occurs during which step of protein synthesis?

Answer 25

Translation