$$\text{BMR} = \frac{\text{Energy expended}}{\text{Time}}$$

Question 1

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

Accepted Answer

Actin filaments slide past myosin filaments, shortening the sarcomere.

Question 2

During muscle contraction, which sequence correctly represents the order of events after a nerve impulse initiates the process?

Accepted Answer

Release of acetylcholine → depolarization of muscle cell membrane → calcium release from sarcoplasmic reticulum → actin-myosin cross-bridge formation

Question 3

Which equation best represents the relationship between pressure, volume, and airflow in the lungs during inhalation?

Accepted Answer

$$P_1V_1 = P_2V_2$$

Question 4

Which muscle group is primarily responsible for changing the volume of the thoracic cavity during breathing?

Accepted Answer

Intercostal muscles

Question 5

A patient with a mutation in the gene coding for myosin would most likely experience which of the following?

Accepted Answer

Impaired muscle contraction due to inability to form actin-myosin cross-bridges

Question 6

Which of the following best explains why breathing is essential for humans?

Accepted Answer

It provides oxygen for cellular respiration and removes carbon dioxide, maintaining acid-base balance.

Question 7

During inspiration, which of the following occurs?

Accepted Answer

The diaphragm contracts and moves downward, increasing thoracic volume and decreasing lung pressure.

Question 8

Which structure in the digestive system is primarily responsible for nutrient absorption due to its large surface area?

Accepted Answer

Small intestine

Question 9

Which equation best represents basal metabolic rate (BMR) in terms of energy expenditure?

Accepted Answer

$$	ext{BMR} = \frac{	ext{Energy expended}}{	ext{Time}}$$

Question 10

Which accessory organ produces enzymes that aid in the digestion of carbohydrates, proteins, and fats?

Accepted Answer

Pancreas

Question 11

A person with a genetic disorder caused by a dominant allele will display the disorder if their genotype is:

Accepted Answer

Homozygous dominant or heterozygous

Question 12

Which of the following best describes the Law of Segregation?

Accepted Answer

Each parent passes only one allele for each gene to their offspring during gamete formation.

Question 13

If a trait is controlled by polygenic inheritance, which of the following is true?

Accepted Answer

Multiple genes contribute to the phenotype, resulting in a range of variations.

Question 14

Which of the following best describes incomplete dominance?

Accepted Answer

The heterozygote expresses a phenotype intermediate between the two homozygotes.

Question 15

A child inherits a sex-linked gene for color blindness from their mother. Which of the following is most likely true?

Accepted Answer

The gene is located on the X chromosome, and the child is male.

Question 16

Which of the following best explains how new combinations of alleles can develop during meiosis?

Accepted Answer

Crossing over between homologous chromosomes

Question 17

Which of the following is a function of the sarcomere?

Accepted Answer

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

Question 18

Which of the following best describes peristalsis?

Accepted Answer

Wave-like contractions of smooth muscle that move food through the digestive tract.

Question 19

A karyotype is used to:

Accepted Answer

Visualize the number and structure of chromosomes in a cell.

Question 20

Which of the following best explains why some recessive disorders are still prevalent in human populations?

Accepted Answer

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

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

Study Guide - Practice Questions