Unit 1 - q&a Flashcards
Which statement about microRNAs (miRNAs) is correct?
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.
Compared with the intracellular fluid, the extracellular fluid has
__________ sodium ion concentration,
__________ potassium ion concentration,
__________ chloride ion concentration, and
__________ phosphate ion concentration
Higher, lower, higher, lower
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?
Cell-specific expression and repression of specific
genes
telomeres in cancer cells:
In cancer cells, telomerase activity is usually reduced compared with normal cells
telomers are:
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
Which of the following events does not occur during
the process of mitosis?
Replication of the genome
The term “glycocalyx” refers to what?
The negatively charged carbohydrate layer on the
outer cell surface
Which statement is incorrect?
In most diseases, homeostatic mechanisms are no
longer operating in the body
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.
Golgi apparatus
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.
Glycocalyx
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.
Lysosomes
cellular location of Protein condensation and packaging
Golgi apparatus
cellular location of Initiation of translation
Cytosol
cellular location of Gene transcription
Nucleus
Worn-out organelles are transferred to lysosomes by
which of the following?
Autophagosomes - double membrane structures called formed in the cytosol.
Which of the following is not a major function of the
endoplasmic reticulum (ER)?
Secretion of proteins synthesized in the cell
Which of the following does not play a direct role in the process of transcription?
Helicase
Which statement is true for both pinocytosis and
phagocytosis?
Involves the recruitment of actin filaments
Which of the following proteins is most likely to be the product of a proto-oncogene?
Growth factor receptor
Which statement is incorrect about oncogenes
Inactivation of anti-oncogenes protects against the
development of cancer
Which statement about feedback control systems is incorrect?
Positive feedback usually promotes stability in a
system
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?
−1.0
Which of the following cell organelles is responsible for producing adenosine triphosphate (ATP), the energy Currency of the cell?
Mitochondria
Which statement about mRNA is correct?
mRNA carries the genetic code to the cytoplasm
“Redundancy” or “degeneration” of the genetic code
occurs during which step of protein synthesis?
Translation
