Which component of the cell membrane is primarily responsible for the membrane

1
Which component of the cell membrane is primarily
responsible for the membranes ability to form a
physical barrier between the cells internal and
external environments?
1. Phospholipid bilayer 2. Glycocalyx 3.
Peripheral proteins 4. Proteoglycans
2
Which type of integral protein allows water and
small ions to pass through the cell membrane?
1. Receptor proteins 2. Carrier proteins 3.
Channel proteins 4. Recognition proteins
3
Which statement(s) correctly distinguish between
cytoplasm and cytosol?

• 1. Cytosol has a higher concentration of
  suspended proteins than cytoplasm.
• 2. Cytosol is the intracellular fluid and is
  composed of nutrients, ions, proteins, and
  wastes and cytoplasm is the term for all
  material located between the cell membrane and
  nucleus.
• 3. Potassium ion concentration is higher in
  cytoplasm than in cytosol.
• 4. Cytosol and cytoplasm refer to the same
  substance.

4
What is/are the major difference(s) between
cytosol and extracellular fluid?
1. Cytosol has a higher concentration of sodium
ions 2. ECF is a transport medium only, whereas
cytosol has some carbohydrates and amino acids 3.
Cytosol has a higher concentration of potassium
ions 4. 2 and 3
5
Which of the listed organelles is non-membranous
and correctly paired with its function?

• 1. Microvilli/movement of materials over cell
  surface
• 2. Ribosomes/protein synthesis
• 3. Mitochondria/produces ATP required by cell
• 4. Microtubules/increase surface area for
  absorption

6
What does the presence of many mitochondria imply
about a cells energy requirements?
1. A high demand for energy 2. A low demand for
energy 3. Fluctuating energy needs requiring
flexibility 4. Number of mitochondria provides
no implication of energy needs
7
Certain cells in the ovaries and testes contain
large amounts of smooth endoplasmic reticulum
(SER). Why?
1. To produce large amounts of proteins 2. To
digest materials quickly 3. To store large
amounts of hormones 4. To produce large amounts
of steroid hormones
8
Cells lining the small intestine have numerous
fingerlike projections on their free surface.
What are these structures, and what is their
function?
1. Microvilli move substances across cell
surface 2. Microvilli increase cells surface
area and absorptive ability 3. Cilia increase
cells surface area and absorptive ability 4.
Cilia move substances across cell surface
9
What is the genetic code?

• 1. It is the method by which proteins code for
  amino acids.
• 2. It is the language the cell uses in the
  form of triplet codons, which specify individual
  amino acids.
• 3. It is the portion of DNA that contains
  instructions for the synthesis of tRNA.
• 4. It is the strand of DNA containing
  complementary triplets used for mRNA production.

10
What process would be affected by the lack of the
enzyme RNA polymerase?
1. Nothing would be affected DNA polymerase
would take over 2. Cells ability to duplicate
DNA 3. Cells ability to translate DNA 4.
Cells ability to transcribe RNA
11
What are two reasons that mRNA transcription so
vital?

• 1. Protein synthesis occurs through
  transcription/it occurs very quickly
• 2. DNA cannot leave the nucleus/transcription
  ensures that mRNA exactly matches the coding
  strand of the gene
• 3. It allows formation of chains of amino
  acids/the same information is presented in a
  different language
• 4. None of these is correct

12
Define selectively permeable as it applies to
the cell membrane.

• 1. It is a membrane through which nothing can
  pass.
• 2. It is a membrane that allows the free passage
  of some molecules, but restricts the passage of
  others.
• 3. It is a membrane through which any substance
  can pass without restriction.
• 4. It is a membrane that only allows substances
  through by active transport.

13
How would a decrease in the concentration of
oxygen in the lungs affect the diffusion of
oxygen into the blood?

1. Decrease in molecule size results in decreased
   diffusion
2. Decrease in distance results in increased
   diffusion
3. Increase in electrical forces results in
   increased diffusion
4. Decrease in gradient size results in decreased
   speed of diffusion

14
What is so special about osmosis, compared with
diffusion?

• 1. Osmosis allows free passage of alcohol, fatty
  acids, and steroids through the plasma membrane.
• 2. Osmosis is the movement of water rather than
  solute.
• 3. In osmosis, water flows across a membrane
  toward the solution that has a higher
  concentration of solutes, because that is where
  water concentration is lower.
• 4. 2 and 3 are correct.

15
Some Pediatricians recommend the use of a 10
salt solution to relieve congestion for infants
with stuffy noses. What effect would such a
solution have on the cells lining the nasal
cavity, and why?
1. Cells will lose water because this is a
hypertonic solution. 2. Cells will lose water
because this is a hypotonic solution. 3. Cells
will gain water because this is a hypertonic
solution. 4. Cells will gain water because this
is a hypotonic solution.
16
All methods of carrier-mediated transport have
the following characteristics ___.

• 1. Concentration gradients, transmembrane
  potential, and resting potential
• 2. Specificity, saturation limits, and
  regulation
• 3. Endocytosis, exocytosis, and pinocytosis
• 4. Isotonic, hypertonic, and hypotonic solutions

17
Which of the following methods of
carrier-mediated transport is paired with its
function?

• 1. Active transport/it is dependent on a
  concentration gradient
• 2. Facilitated diffusion/substances are bound to
  a receptor and passed across the cell membrane by
  carrier proteins
• 3. Sodium-potassium pump/moves Na outside the
  cell and K inside the cell
• 4. 2 and 3 are correct

18
During digestion in the stomach, the
concentration of hydrogen ions (H) rises to many
times that of cells in the stomach. Which
transport process must be operating?
1. Facilitated diffusion 2. Osmosis 3. Active
transport 4. Endocytosis
19
When they encounter bacteria, certain types of
white blood cells engulf the bacteria and bring
them into the cell. What is this process called?
1. Pseudocytosis 2. Exocytosis 3. Pinocytosis
4. Phagocytosis
20
Each type of cell has a characteristic resting
potential. Which is correct?

• 1. Fat cells (-40 mV)
• 2. Neurons (-70 mV)
• 3. Cardiac muscle cells (-90 mV)
• 4. All of the above are correct

21
If the cell membrane were freely permeable to
sodium ions (Na), how would the transmembrane
potential be affected?
1. It would not change 2. It would become more
positive 3. It would become more negative 4. It
would become unstable
22
During the S phase, which of the following
occur(s)?

• 1. DNA polymerase binds to exposed nitrogenous
  bases
• 2. DNA replication
• 3. Synthesis of histone proteins in the nucleus
• 4. All of the above are correct

23
A cell is actively manufacturing enough
organelles to serve two functional cells. This
cell is probably in which phase of its life cycle?
1. S 2. G1 3. G2 4. M
24
During DNA replication, a nucleotide is deleted
from a sequence that normally codes for a
polypeptide. What effect will this deletion have
on the amino acid sequence of the polypeptide?
1. No effect, deletion will be skipped 2. No
effect, deletion will be automatically
repaired 3. Amino acid sequence will
disintegrate 4. Amino acid sequence would be
altered
25
What would happen if spindle fibers failed to
form in a cell during mitosis?
1. Centromeres would not appear 2. Nuclear
membrane would not disintegrate 3. Chromosomes
would not separate 4. Chromatin would not
condense
26
Which of the following stages of mitosis is
correctly paired with the events of that stage?

• 1. Anaphase/centromeres of chromatid pairs
  separate and daughter chromosomes are pulled to
  opposite ends of the cell
• 2. Prophase/chromatids are aligned along center
  of the cell
• 3. Telophase/chromosomes condense and nuclear
  membrane fragments
• 4. All of the above are correct