Question 1

Which of the following best explains why antibiotics such as penicillin are effective against bacteria but not human cells?

Accepted Answer

Penicillin targets the peptidoglycan layer in bacterial cell walls, which is absent in human cells.

Question 2

A patient is diagnosed with a mitochondrial disorder that impairs ATP production. Which cellular process is most directly affected?

Accepted Answer

Cellular respiration, specifically oxidative phosphorylation

Question 3

Which of the following cell junctions is most critical for preventing leakage of digestive enzymes between epithelial cells lining the stomach?

Accepted Answer

Tight junctions

Question 4

During which phase of the cell cycle does DNA replication occur, and what is the significance of this process?

Accepted Answer

S phase; it ensures that each daughter cell receives an identical set of genetic material

Question 5

A muscle cell is deprived of oxygen. Which metabolic pathway will it rely on for ATP production, and what is the main byproduct?

Accepted Answer

Lactic acid fermentation; lactic acid

Question 6

Which of the following statements about viruses is correct?

Accepted Answer

Viruses require host cell machinery to replicate their genetic material and produce new virions.

Question 7

A Gram-negative bacterium is more resistant to certain antibiotics than a Gram-positive bacterium. What structural feature accounts for this difference?

Accepted Answer

An outer membrane containing lipopolysaccharides

Question 8

A woman is a carrier for an X-linked recessive disorder. If she has a child with a man who does not have the disorder, what is the probability that their son will be affected?

Accepted Answer

$$0.5$$

Question 9

Which enzyme is responsible for joining Okazaki fragments during DNA replication?

Accepted Answer

DNA ligase

Question 10

Which tissue type is specialized for rapid communication and control of body functions?

Accepted Answer

Nervous tissue

Question 11

A person with damage to the cochlea would most likely experience which of the following symptoms?

Accepted Answer

Hearing loss due to impaired mechanoreceptors

Question 12

Which glial cell type is primarily responsible for forming the myelin sheath in the central nervous system?

Accepted Answer

Oligodendrocytes

Question 13

Which of the following best describes the role of the sodium-potassium pump in maintaining the resting membrane potential of a neuron?

Accepted Answer

It actively transports $$3 Na$^+$$ ions out and $$2 K$^+$$ ions into the cell, creating a negative charge inside.

Question 14

A steroid hormone such as cortisol exerts its effects by:

Accepted Answer

Crossing the plasma membrane and binding to intracellular receptors to regulate gene expression.

Question 15

Which of the following is a primary function of antibodies in the immune response?

Accepted Answer

Binding to antigens to neutralize pathogens or mark them for destruction

Question 16

A patient presents with high blood pressure and is found to have excessive aldosterone secretion. Which of the following best explains the effect of aldosterone on blood pressure?

Accepted Answer

Aldosterone increases sodium reabsorption in the kidneys, leading to increased water retention and higher blood volume.

Question 17

Which of the following best describes the mechanism of negative pressure breathing in humans?

Accepted Answer

Contraction of the diaphragm increases thoracic cavity volume, decreasing pressure and drawing air into the lungs.

Question 18

A person with iron-deficiency anemia would most likely have impaired:

Accepted Answer

Oxygen transport due to reduced hemoglobin levels

Question 19

Which of the following best explains why a population that has undergone a bottleneck event is at increased risk for genetic disorders?

Accepted Answer

Reduced genetic diversity increases the likelihood of homozygosity for deleterious alleles.

Question 20

In a population at Hardy-Weinberg equilibrium, if the frequency of the recessive allele ($$q) is$$ $$0.3$$, what is the expected frequency of heterozygotes?

Accepted Answer

$$2pq = 2 	imes 0.7 	imes 0.3 = 0.42$$

Comprehensive Study Notes for College Biology: Cell Biology, Genetics, Physiology, and Evolution

Study Guide - Practice Questions

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