Question 1

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

Accepted Answer

Actin filaments slide past myosin filaments, shortening the sarcomere and causing muscle contraction.

Question 2

A patient is unable to generate enough body heat and is diagnosed with a disorder affecting the system responsible for most heat production. Which system is most likely affected?

Accepted Answer

Muscular system

Question 3

During muscle contraction, which event occurs immediately after the action potential reaches the muscle fiber?

Accepted Answer

Release of calcium ions from the sarcoplasmic reticulum

Question 4

Which of the following best explains the difference between isotonic and isometric muscle contractions?

Accepted Answer

Isotonic contractions change muscle length, while isometric contractions do not change muscle length.

Question 5

Which muscle group is primarily responsible for separating the thoracic and abdominal cavities and plays a key role in breathing?

Accepted Answer

Diaphragm

Question 6

During inhalation, what happens to the pressure inside the lungs relative to atmospheric pressure?

Accepted Answer

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

Question 7

Which of the following correctly describes the path of oxygen-rich blood through the heart?

Accepted Answer

Pulmonary veins → left atrium → left ventricle → aorta

Question 8

Which structure in the respiratory system is primarily responsible for warming, humidifying, and filtering incoming air?

Accepted Answer

Nasal cavity

Question 9

A person with a genetic disorder has a karyotype showing 47 chromosomes, including three copies of chromosome 21. What is this condition called?

Accepted Answer

Down syndrome (Trisomy 21)

Question 10

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

Accepted Answer

Alleles of different genes assort independently during gamete formation.

Question 11

Which of the following is an example of codominance in human genetics?

Accepted Answer

AB blood type, where both A and B alleles are equally expressed

Question 12

A child inherits one allele for brown eyes (B, dominant) and one for blue eyes (b, recessive). What is the child's genotype and phenotype?

Accepted Answer

Genotype: Bb; Phenotype: Brown eyes

Question 13

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 14

Which process is responsible for moving food through the digestive tract by coordinated muscle contractions?

Accepted Answer

Peristalsis

Question 15

Which accessory organ produces enzymes that are released into the small intestine to aid in digestion of all macromolecules?

Accepted Answer

Pancreas

Question 16

Why is a large surface area important in the small intestine?

Accepted Answer

It increases nutrient absorption by providing more area for diffusion.

Question 17

Which of the following best describes the difference between basal metabolic rate (BMR) and standard metabolic rate (SMR)?

Accepted Answer

BMR is measured under resting, fasting, and thermoneutral conditions; SMR is measured under variable conditions.

Question 18

A woman who is a carrier for a sex-linked recessive disorder (X	extsuperscript{N}X	extsuperscript{n}) and a man who does not have the disorder (X	extsuperscript{N}Y) have a son. What is the probability that their son will have the disorder?

Accepted Answer

$$\frac{1}{2}$$

Question 19

Which of the following best describes incomplete dominance?

Accepted Answer

The heterozygote expresses a phenotype intermediate between the two homozygotes.

Question 20

Which of the following scenarios best illustrates the effect of linked genes?

Accepted Answer

Two genes located close together on the same chromosome are inherited together more often than not.

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

Study Guide - Practice Questions

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