Question 1

If cells are placed in a hypotonic solution containing a solute to which the membrane is impermeable, what could happen?
A) The cells would swell and cell lysis could occur.
B) The cells would lose water and crenate.
C) The cells would crenate at first, but then reach equilibrium with the surrounding solution.
D) The cells would show no change.
E) The cells would maintain a low hydrostatic pressure.

Accepted Answer

In a hypotonic solution, water moves into the cells due to osmosis, causing them to swell and potentially burst (lysis) because the solute cannot pass through the membrane to balance the concentration.

Question 2

A red blood cell placed in a hypotonic solution would
A) crenate.
B) swell, then crenate as equilibrium is reached.
C) neither crenate nor swell.
D) swell and lyse.
E) have a low osmotic pressure compared to the solution.

Accepted Answer

A red blood cell in a hypotonic solution will swell and potentially lyse because water moves into the cell where the solute concentration is higher.

Question 3

Which of the following is the most plentiful positive ion in the extracellular fluid?
A) potassium
B) sodium
C) magnesium
D) chloride
E) hydrogen

Accepted Answer

Sodium is the most abundant positive ion (cation) in the extracellular fluid, playing a crucial role in maintaining fluid balance and nerve function.

Question 4

Which of the following is FALSE regarding the sodium-potassium pump? A) It is a type of primary active transport antiporter. B) It changes conformation after being phosphorylated, and expels sodium from inside the cell. C) It relies on the hydrolysis of ATP in order to function. D) It imports three K⁺ for every 2 Na⁺ it exports from the cell. E) It releases its phosphate group after it binds to extracellular K⁺.

Accepted Answer

The sodium-potassium pump exports three Na⁺ ions and imports two K⁺ ions, not the other way around.

Question 5

If a tRNA had an AGC anticodon, it could bind with a(n) ___ mRNA codon.
A) UGA
B) AUG
C) UCG
D) TCG
E) GAU

Accepted Answer

The anticodon of a tRNA is complementary to the codon of the mRNA. So, if the tRNA has an AGC anticodon, it could bind with a UCG mRNA codon.

Question 6

Which of the following is NOT an example of hydrogen bonding? A) The bonds formed between base pairs of nucleotides in DNA. B) The bonds formed between neighboring amino acids to form a protein's secondary structure. C) The bonds formed between amino acids to form a protein's primary structure. D) The bonds formed between molecules of H₂O. E) The bonds formed between the hydroxyl groups of cholesterol molecules and the surrounding polar heads of the phospholipids in the plasma membrane.

Accepted Answer

The bonds formed between amino acids to form a protein's primary structure are peptide bonds, not hydrogen bonds.

Question 7

Put the steps of the sodium-potassium pump in the correct order.
1) potassium binds to protein pump
2) sodium binds to protein
3) phosphate group is released from protein pump
4) release of potassium into ICF
5) hydrolysis of ATP
6) expelling of sodium
A) 1, 2, 3, 4, 5, 6
B) 2, 5, 6, 1, 3, 4
C) 3, 4, 2, 6, 5, 1
D) 5, 6, 3, 4, 2, 1
E) 3, 2, 4, 6, 1, 5

Accepted Answer

The sodium-potassium pump process begins with sodium binding to the protein, followed by ATP hydrolysis, expelling sodium, potassium binding, phosphate release, and finally releasing potassium into the ICF.

Question 8

A human cell placed in a 2% NaCl solution (a hypertonic solution) would
A) swell and lyse.
B) have a low osmotic pressure compared to the solution.
C) maintain its shape.
D) maintain a very high hydrostatic pressure.
E) exhibit no change.

Accepted Answer

A hypertonic solution has a higher concentration of solutes than the cell's cytoplasm, causing water to move out of the cell, resulting in the cell shrinking. Thus, the cell has a lower osmotic pressure compared to the hypertonic solution.

Question 9

If a 0.92% saline (NaCl) solution is isotonic to a cell, a 0.3% NaCl solution ___.
A) would cause the cell to shrink
B) would result in water movement into the cell
C) would cause the cell to crenate
D) is hypertonic to the cell
E) is hyperosmotic to the cell

Accepted Answer

A 0.3% NaCl solution is hypotonic compared to the 0.92% isotonic solution, leading to water moving into the cell, potentially causing it to swell or burst.

Question 10

A red blood cell placed in distilled (pure) water (which is hypotonic) would
A) swell and burst.
B) shrink.
C) swell, then shrink as equilibrium is reached.
D) neither shrink nor swell.
E) maintain a low hydrostatic pressure.

Accepted Answer

A red blood cell placed in distilled water, which is hypotonic, will swell and burst due to osmotic pressure as water moves into the cell where the solute concentration is higher.

Question 11

The cell does not need to expend energy (ATP) in order to perform ___.
A) exocytosis
B) receptor-mediated endocytosis
C) simple diffusion
D) active transport
E) phagocytosis

Accepted Answer

Simple diffusion is a passive transport process where molecules move from an area of higher concentration to an area of lower concentration without the use of cellular energy (ATP).

Question 12

Which statement is the most correct regarding the processes of transcription and translation?
A) The nucleotide sequence in an mRNA codon is an exact copy of the DNA triplet that coded for the mRNA, except that uracil replaces adenine.
B) The nucleotide sequence in an mRNA codon is an exact copy of the DNA triplet that coded for the mRNA, except that uracil replaces thymine.
C) The nucleotide sequence in an rRNA codon is an exact copy of the DNA triplet that coded for mRNA, except that uracil replaces adenine.
D) The nucleotide sequence in a tRNA anticodon is an exact copy of the DNA triplet that coded for an mRNA, except that uracil replaces adenine.
E) The nucleotide sequence in a tRNA anticodon is an exact copy of the DNA triplet that coded for an mRNA, except that uracil replaces thymine.

Accepted Answer

The answer of Which statement is the most correct regarding...

Question 13

Which of the following cell types would you expect to have an unusually high abundance of free ribosomes?
A) fibroblasts
B) osteoblasts
C) skeletal muscle cells
D) liver cells (which produce many of the proteins found in blood)
E) chondroblasts

Accepted Answer

Skeletal muscle cells have a high abundance of free ribosomes because they synthesize large amounts of proteins for muscle contraction and maintenance.

Question 14

During ___, the chromosomal centromeres split and the chromosomes migrate to opposite ends of the cell.
A) metaphase
B) anaphase
C) telophase
D) prophase
E) S phase

Accepted Answer

During anaphase, the chromosomal centromeres split and the chromosomes migrate to opposite ends of the cell.

Question 15

Which of the following statements is most correct regarding the sodium-potassium pump?
A) The ATP driven pump operates as a symport system.
B) The pump transports 3 potassium ions into the cell for every 2 sodium ions it transports out of the cell.
C) Phosphorylation of the ATPase transport protein causes a conformational change resulting in the expulsion of sodium into the extracellular fluid.
D) When potassium binds to the ATPase transport protein, the protein is phosphorylated.
E) It is a secondary transport pump.

Accepted Answer

The sodium-potassium pump uses ATP to phosphorylate the ATPase transport protein, causing a conformational change that expels sodium ions into the extracellular fluid.

Question 16

Put the steps of the sodium-potassium pump in the correct order.
1) potassium binds to protein pump
2) sodium binds to protein
3) potassium released into ICF
4) hydrolysis of ATP
5) sodium expelled
A) 1, 2, 3, 4, 5
B) 2, 4, 5, 1, 3
C) 3, 4, 2, 5, 1
D) 5, 3, 4, 2, 1
E) 3, 2, 4, 1, 5

Accepted Answer

The sodium-potassium pump process starts with sodium binding to the protein, followed by ATP hydrolysis, sodium expulsion, potassium binding, and finally potassium release into the intracellular fluid.

Question 17

In which phase of the cellular cycle does DNA replication occur?
A) prophase
B) metaphase
C) S phase
D) G2 phase
E) telophase

Accepted Answer

DNA replication occurs during the S phase (Synthesis phase) of the cell cycle.

Question 18

___ can be thought of as "cell eating" and is practiced frequently by white blood cells, which use it to neutralize bacteria, viruses, and dead or dying cells.
A) Pinocytosis
B) Exocytosis
C) Phagocytosis
D) Autolysis
E) Hydrolysis

Accepted Answer

Phagocytosis is the process by which cells, particularly white blood cells, engulf and digest large particles, such as bacteria, viruses, and dead or dying cells, effectively "eating" them.

Question 19

Which of the following would NOT increase the rate of diffusion?
A) A decrease in the size of the diffusing particle.
B) An increase in the concentration gradient.
C) An enzyme acting as a catalyst.
D) An increase in the temperature.
E) A decrease in the thickness of the membrane across which diffusion was occurring.

Accepted Answer

Enzymes act as catalysts for chemical reactions, not for physical processes like diffusion. Therefore, they do not affect the rate of diffusion.

Question 20

Which of the following is a FALSE statement regarding the cytoplasmic organelles? A) The Golgi complex is the site of protein transcription. B) The smooth endoplasmic reticulum in muscle cells serves to store Ca²⁺ (ionic calcium). C) Mitochondria are sites for the processes involved with cellular respiration (using oxygen to produce ATP), and contain their own DNA. D) Ribosomes consist of large and small subunits, both of which are made in the nucleolus of the cell. E) Lysosomes are membrane-enclosed vesicles that contain powerful digestive enzymes that work best at an acidic pH.

Accepted Answer

The Golgi complex is involved in modifying, sorting, and packaging proteins for secretion, not in protein transcription. Protein transcription occurs in the nucleus.

Quiz 3: The Cellular Level of Organization

If cells are placed in a hypotonic solution containing a solute to which the membrane is impermeable, what could happen?

A red blood cell placed in a hypotonic solution would

Which of the following is the most plentiful positive ion in the extracellular fluid?

Which of the following is FALSE regarding the sodium-potassium pump?

If a tRNA had an AGC anticodon, it could bind with a(n) ___ mRNA codon.

Which of the following is NOT an example of hydrogen bonding?

Put the steps of the sodium-potassium pump in the correct order. 1) potassium binds to protein pump 2) sodium binds to protein 3) phosphate group is released from protein pump 4) release of potassium into ICF 5) hydrolysis of ATP 6) expelling of sodium

A human cell placed in a 2% NaCl solution (a hypertonic solution) would

If a 0.92% saline (NaCl) solution is isotonic to a cell, a 0.3% NaCl solution ___.

A red blood cell placed in distilled (pure) water (which is hypotonic) would

The cell does not need to expend energy (ATP) in order to perform ___.

Which statement is the most correct regarding the processes of transcription and translation?

Which of the following cell types would you expect to have an unusually high abundance of free ribosomes?

During ___, the chromosomal centromeres split and the chromosomes migrate to opposite ends of the cell.

Which of the following statements is most correct regarding the sodium-potassium pump?

Put the steps of the sodium-potassium pump in the correct order. 1) potassium binds to protein pump 2) sodium binds to protein 3) potassium released into ICF 4) hydrolysis of ATP 5) sodium expelled

In which phase of the cellular cycle does DNA replication occur?

___ can be thought of as "cell eating" and is practiced frequently by white blood cells, which use it to neutralize bacteria, viruses, and dead or dying cells.

Which of the following would NOT increase the rate of diffusion?

Which of the following is a FALSE statement regarding the cytoplasmic organelles?