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 heat to maintain body temperature in a cold environment. Which system is most likely impaired?

Accepted Answer

Muscular system

Question 3

During muscle contraction, which ion is released from the sarcoplasmic reticulum to initiate the interaction between actin and myosin?

Accepted Answer

Calcium ($$\mathrm{Ca$$^{2+}$$})$$

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 structure separates the thoracic cavity from the abdominal cavity and plays a key role in respiration?

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 enzyme is produced in the stomach and is responsible for the initial breakdown of proteins?

Accepted Answer

Pepsin

Question 9

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

Accepted Answer

It increases nutrient absorption by maximizing contact with digested food.

Question 10

Which of the following best describes peristalsis?

Accepted Answer

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

Question 11

A person has a genotype $$Aa$$ for a particular gene. Which of the following statements is correct?

Accepted Answer

The person is heterozygous for that gene.

Question 12

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

Accepted Answer

Alleles of different genes are distributed independently of one another during gamete formation.

Question 13

A child inherits blood type AB from their parents. Which inheritance pattern does this illustrate?

Accepted Answer

Codominance

Question 14

Which of the following scenarios best illustrates incomplete dominance?

Accepted Answer

A cross between red-flowered and white-flowered plants produces pink-flowered offspring.

Question 15

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

Accepted Answer

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

Question 16

Which of the following is a consequence of nondisjunction during meiosis?

Accepted Answer

Gametes with abnormal numbers of chromosomes, such as in Down syndrome.

Question 17

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

Accepted Answer

$$50\%$$

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 best explains how environmental factors can influence phenotypic expression?

Accepted Answer

Environmental factors can affect gene expression, leading to different phenotypes from the same genotype.

Question 20

Which of the following is the correct definition of a karyotype?

Accepted Answer

A visual representation of all the chromosomes in a cell, used to detect chromosomal abnormalities.

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

Study Guide - Practice Questions

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