Question 1

Which of the following best describes the sliding filament mechanism in skeletal muscle contraction?

Accepted Answer

Myosin heads bind to actin, pulling actin filaments toward the center of the sarcomere, causing the sarcomere to shorten.

Question 2

A patient is unable to generate sufficient body heat in a cold environment. Which system is most likely impaired?

Accepted Answer

Muscular system

Question 3

During inhalation, which of the following best describes the change in pressure inside the lungs?

Accepted Answer

Lung pressure decreases below atmospheric pressure, causing air to flow in.

Question 4

Which of the following best explains the function of the intercostal muscles during breathing?

Accepted Answer

They contract during inhalation to expand the rib cage and relax during exhalation to decrease thoracic volume.

Question 5

Which of the following is the correct order of events leading to muscle contraction after a nerve impulse?

Accepted Answer

Release of acetylcholine → depolarization of sarcolemma → release of calcium ions → actin-myosin cross-bridge formation

Question 6

Which of the following best describes the function of enzymes in the human digestive system?

Accepted Answer

They chemically catalyze the breakdown of macromolecules into absorbable units.

Question 7

A person has a mutation that prevents the production of bile. Which digestive process would be most affected?

Accepted Answer

Digestion of lipids

Question 8

Which of the following best defines a genotype?

Accepted Answer

The genetic makeup of an organism for a specific trait

Question 9

A woman with genotype $$X^N X^n ($$where $$N is $$normal vision and $$n is $$color blindness) and a man with genotype $$X^n Y$$ have a child. What is the probability that their son will be color blind?

Accepted Answer

$$0.25$$

Question 10

Which of the following best describes the Law of Independent Assortment?

Accepted Answer

Alleles for different genes segregate independently during gamete formation.

Question 11

Which of the following is an example of incomplete dominance?

Accepted Answer

A red-flowered plant crossed with a white-flowered plant produces pink-flowered offspring.

Question 12

Which of the following best explains why some recessive genetic disorders remain prevalent in human populations?

Accepted Answer

Carriers (heterozygotes) do not express the disorder and can pass the allele to offspring.

Question 13

Which of the following best describes the function of the sarcomere?

Accepted Answer

It is the basic contractile unit of muscle, responsible for muscle shortening.

Question 14

Which of the following is true regarding isotonic and isometric muscle contractions?

Accepted Answer

Isotonic contractions produce movement, while isometric contractions generate tension without changing muscle length.

Question 15

Which of the following best describes the role of the diaphragm in respiration?

Accepted Answer

It contracts to increase thoracic volume, reducing lung pressure and drawing air in.

Question 16

A karyotype is used to:

Accepted Answer

Visualize and count the number of chromosomes in a cell.

Question 17

Which of the following best explains how peristalsis functions in the digestive tract?

Accepted Answer

It is the rhythmic contraction of smooth muscle to propel food along the digestive tract.

Question 18

Which of the following best describes polygenic inheritance?

Accepted Answer

Multiple genes contribute to a single trait, resulting in a range of phenotypes.

Question 19

Which of the following scenarios best illustrates codominance?

Accepted Answer

A person with genotype $$I^A I^B$$ has both A and B antigens on their red blood cells.

Question 20

A geneticist observes that two genes are inherited together more often than expected by chance. Which of the following best explains this observation?

Accepted Answer

The genes are linked and located close together on the same chromosome.

Human Biology Exam 2 Study Guide: Muscular, Respiratory, Digestive Systems & Genetics

Study Guide - Practice Questions

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