Question 1

Which of the following best describes the role of calcium ions ($$\mathrm{Ca$$^{2+}$$}) in $$muscle contraction according to the sliding filament theory?

Accepted Answer

They allow myosin to attach to actin by binding to regulatory proteins.

Question 2

A patient is unable to move their diaphragm due to nerve damage. Which of the following physiological changes would most likely occur during attempted inspiration?

Accepted Answer

Lung volume would not increase significantly, so air intake would be impaired.

Question 3

Which muscle group is primarily responsible for straightening the elbow, and what is its anatomical location?

Accepted Answer

Triceps; back of upper arm

Question 4

During an isometric exercise, such as holding a plank, which of the following best describes what happens to the muscle?

Accepted Answer

The muscle length stays the same, but tension increases.

Question 5

A person inhales deeply. Which sequence of events correctly describes the changes in the thoracic cavity and air movement?

Accepted Answer

Diaphragm contracts, lung volume increases, pressure decreases, air moves in.

Question 6

Which structure is the primary site of gas exchange in the human respiratory system?

Accepted Answer

Alveoli

Question 7

A person with emphysema has damaged alveoli. What is the most direct consequence of this damage?

Accepted Answer

Difficulty in gas exchange, leading to lower oxygen in the blood.

Question 8

Which of the following correctly traces the path of blood flow through the heart and lungs, starting from the body?

Accepted Answer

Body → right atrium → right ventricle → pulmonary arteries → lungs → pulmonary veins → left atrium → left ventricle → aorta → body

Question 9

Which enzyme is responsible for beginning the breakdown of starch in the mouth?

Accepted Answer

Amylase

Question 10

A patient has a blockage in their pancreatic duct. Which digestive process would be most directly affected?

Accepted Answer

Breakdown of proteins, carbohydrates, and fats in the small intestine

Question 11

Which of the following best explains why the small intestine has villi and microvilli?

Accepted Answer

To increase surface area for nutrient absorption

Question 12

A person is heterozygous for a gene (genotype $$Bb). $$According to Mendelian genetics, what percentage of their gametes will carry the $$b$$ allele?

Accepted Answer

$$50\%$$

Question 13

If two parents with genotypes $$Bb$$ and $$Bb$$ have a child, what is the probability that the child will have the recessive phenotype?

Accepted Answer

$$25\%$$

Question 14

Which of the following scenarios is an example of incomplete dominance?

Accepted Answer

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

Question 15

A male inherits an X-linked recessive allele for color blindness from his mother. What is his phenotype?

Accepted Answer

He will be color blind.

Question 16

Which process during meiosis increases genetic variation by exchanging DNA between homologous chromosomes?

Accepted Answer

Crossing over

Question 17

A karyotype shows three copies of chromosome 21. What is the most likely diagnosis?

Accepted Answer

Down syndrome (trisomy 21)

Question 18

Which of the following best explains why recessive genetic disorders can remain common in a population?

Accepted Answer

Carriers (heterozygotes) do not show symptoms but can pass the allele to offspring.

Question 19

Which statement best describes the Law of Independent Assortment?

Accepted Answer

Different genes are usually inherited independently, creating new combinations of traits.

Question 20

A person eats a meal high in carbohydrates, proteins, and fats. Which enzymes will be active in the small intestine to digest these macromolecules?

Accepted Answer

Amylase, trypsin, and lipase

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

Study Guide - Practice Questions

Study Guide - Flashcards