Question 1

Which of the following best describes the sliding filament theory of muscle contraction?

Accepted Answer

Myosin heads bind to actin filaments and pull them inward, shortening the sarcomere.

Question 2

During a biceps curl, which of the following events occurs at the sarcomere level?

Accepted Answer

Sarcomeres shorten as actin and myosin filaments slide past each other.

Question 3

Which structure stores and releases calcium ions necessary for muscle contraction?

Accepted Answer

Sarcoplasmic reticulum

Question 4

A patient is holding a heavy box steady without moving it. Which type of muscle contraction is primarily occurring?

Accepted Answer

Isometric contraction

Question 5

Which of the following best explains why shivering increases body temperature?

Accepted Answer

Muscle contractions during shivering generate heat as a byproduct of ATP hydrolysis.

Question 6

Which muscle separates the thoracic and abdominal cavities and is essential for breathing?

Accepted Answer

Diaphragm

Question 7

During inhalation, which of the following pressure relationships is true?

Accepted Answer

$$P_{alv} \u003c P_{atm}$$

Question 8

A person inhales deeply. Which muscles are primarily responsible for increasing thoracic volume?

Accepted Answer

Diaphragm and intercostal muscles

Question 9

Which of the following correctly traces the path of oxygen-rich blood from the lungs to the body?

Accepted Answer

Pulmonary veins → left atrium → left ventricle → aorta → systemic circulation

Question 10

A patient with emphysema has difficulty with gas exchange. Which structure is most directly affected?

Accepted Answer

Alveoli

Question 11

Which of the following best describes peristalsis in the digestive system?

Accepted Answer

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

Question 12

Which structure increases the surface area for nutrient absorption in the small intestine?

Accepted Answer

Villi and microvilli

Question 13

A person consumes a meal high in protein. Which organ produces enzymes that begin protein digestion?

Accepted Answer

Stomach

Question 14

Which of the following best defines basal metabolic rate (BMR)?

Accepted Answer

The energy expended at rest to maintain vital functions

Question 15

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

Accepted Answer

Genotype: Bb; Phenotype: Brown eyes

Question 16

Which of the following best describes codominance?

Accepted Answer

Both alleles are fully expressed in the phenotype

Question 17

A genetic cross between two heterozygous individuals (Aa × Aa) is performed. According to the law of segregation, what is the expected genotypic ratio among the offspring?

Accepted Answer

$$1\ \mathrm{AA} : 2\ \mathrm{Aa} : 1\ \mathrm{aa}$$

Question 18

Which of the following scenarios best illustrates polygenic inheritance?

Accepted Answer

Human skin color, which is influenced by multiple genes

Question 19

A male inherits a recessive allele for color blindness located on the X chromosome. Which statement best explains why he expresses the trait?

Accepted Answer

Males have only one X chromosome, so a single recessive allele is expressed.

Question 20

Which event during meiosis increases genetic diversity by creating new allele combinations?

Accepted Answer

Crossing over between homologous chromosomes

Study Notes: Muscular, Respiratory, Digestive Systems & Genetics for Medical Terminology

Study Guide - Practice Questions

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