Quiz: Human Biosciences Foundations — 29 questions

1. Which description correctly distinguishes plasma from formed elements?

A. Plasma is the liquid component, while formed elements are suspended cellular components

B. Plasma forms clots, while formed elements carry hormones in solution

C. Plasma consists of blood cells, while formed elements are dissolved nutrients

D. Plasma contains nuclei, while formed elements lack cellular structure

Answer: (A)

Explanation

Blood contains liquid plasma and formed elements such as red blood cells, white blood cells, and platelets. Formed elements are cellular components suspended in plasma, not dissolved substances within it.

2. Which blood pressure pattern is approximately normal for an adult?

A. 80–84 mmHg during both phases of the heartbeat

B. 120–129 mmHg during both phases of the heartbeat

C. 80–84 mmHg during the heartbeat and 120–129 mmHg between beats

D. 120–129 mmHg during the heartbeat and 80–84 mmHg between beats

Answer: (D)

Explanation

Normal blood pressure is approximately 120–129 mmHg during the heartbeat and 80–84 mmHg between beats. The higher value corresponds to ventricular contraction, whereas the lower value occurs during relaxation.

3. What distinguishes a tissue from an organ?

A. A tissue contains similar cells acting together, whereas an organ contains multiple tissues forming a functional unit

B. A tissue performs body movement, whereas an organ transmits messages through neurons

C. A tissue consists of chemical elements, whereas an organ consists of several complete organisms

D. A tissue contains multiple organs acting together, whereas an organ contains similar cells with one shared function

Answer: (A)

Explanation

A tissue is a collection of similar cells that cooperate in a function, while an organ is a functional unit made from multiple tissues. The second option reverses these organizational definitions.

4. What happens during ventricular systole?

A. The ventricles contract and force blood out of the heart

B. The ventricles relax and fill with returning blood

C. The cardiac valves produce blood pressure between beats

D. The atria contract while the ventricles remain empty

Answer: (A)

Explanation

Ventricular systole is the contraction phase that ejects blood from the ventricles. Ventricular relaxation and filling occur during diastole, not systole.

5. Which field studies the structures of the human body?

A. Anatomy

B. Pathology

C. Physiology

D. Pharmacology

Answer: (A)

Explanation

Anatomy examines the physical structures that make up the human body. Physiology instead focuses on how those structures function.

6. Which example correctly matches a muscle tissue subtype with its location?

A. Cardiac muscle lining blood vessels

B. Skeletal muscle in the stomach wall

C. Cardiac muscle in the heart

D. Smooth muscle attached to the skeleton

Answer: (C)

Explanation

Cardiac muscle is found in the heart and supports its contractions. Skeletal muscle attaches to the skeleton, while smooth muscle occurs in internal organs and blood vessels.

7. In a homeostatic response, which sequence correctly describes the roles of the components?

A. The control centre detects change, effectors set the set point, and receptors restore balance

B. Receptors produce the response, effectors determine the set point, and the control centre senses change

C. Effectors detect change, receptors analyse it, and the control centre produces movement

D. Receptors detect change, the control centre analyses it, and effectors produce a response

Answer: (D)

Explanation

Receptors detect changes, the control centre processes the information, and effectors carry out the corrective response. Effectors do not serve as the sensors that initially detect the change.

8. What does homeostasis describe?

A. Repairing tissues after cellular damage

B. Producing hormones in response to external stimuli

C. Maintaining a stable internal environment

D. Increasing energy use during physical activity

Answer: (C)

Explanation

Homeostasis is the process of maintaining stability within the body's internal environment. Producing hormones can contribute to regulation, but it is not the definition of homeostasis.

9. What occurs across the respiratory membrane in the alveoli?

A. Carbon dioxide enters blood while oxygen enters alveoli

B. Oxygen enters blood while carbon dioxide enters alveoli

C. Glucose enters alveoli while oxygen leaves capillaries

D. Nitrogen enters blood while carbon dioxide enters tissues

Answer: (B)

Explanation

Alveoli are air sacs surrounded by capillaries where oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar air. The other choices reverse or replace the gases involved in this exchange.

10. What is the primary role of the respiratory system in supporting cellular respiration?

A. It distributes hormones and removes nitrogenous wastes

B. It stores glucose and releases metabolic water

C. It supplies oxygen and removes carbon dioxide

D. It converts carbon dioxide into usable cellular energy

Answer: (C)

Explanation

The respiratory system delivers oxygen for ATP production from glucose and removes carbon dioxide produced as waste. The idea that carbon dioxide supplies energy reverses its role in cellular respiration.

11. Which statement about red blood cells is correct?

A. They lack a nucleus and develop from platelets within damaged vessels

B. They lack a nucleus and are produced in red bone marrow by erythropoiesis

C. They contain a nucleus and divide in circulating blood to replace older cells

D. They contain a nucleus and are produced in lymphatic vessels after infection

Answer: (B)

Explanation

Red blood cells lack nuclei, cannot divide, and are produced in red bone marrow through erythropoiesis. The alternatives incorrectly attribute nuclear structure, division, or production to these cells.

12. What is the primary mechanical role of the heart?

A. It filters dissolved substances from circulating plasma

B. It creates pressure that drives blood through the body

C. It returns blood from the body to the heart

D. It exchanges nutrients between blood and surrounding tissues

Answer: (B)

Explanation

The heart is a muscular pump that generates pressure to force blood around the body. Exchange occurs mainly in capillaries, while veins return blood and plasma filtration is not the heart’s primary role.

13. Which blood vessel type has thin walls specialized for exchange of materials?

A. Arteries carrying blood away from the heart

B. Large vessels leaving the thoracic cavity

C. Capillaries connecting arteries and veins

D. Veins returning blood toward the heart

Answer: (C)

Explanation

Capillaries connect arteries and veins and have thin walls that permit material exchange. Arteries and veins primarily transport blood rather than provide the main exchange surface.

14. Which components specifically make up the cardiovascular system?

A. The heart, blood vessels, and lymphatic vessels

B. The heart, lymph nodes, and lymph fluid

C. The blood, lymph fluid, and lymphatic vessels

D. The heart, blood vessels, and blood

Answer: (D)

Explanation

The cardiovascular system consists of the heart, blood vessels, and blood. The broader circulatory system also includes lymphatic vessels and lymph fluid, which makes the other combinations too broad or incomplete.

15. Which form represents the main ways carbon dioxide is transported in the blood?

A. As bicarbonate ions, carbaminohaemoglobin, or dissolved gas

B. As plasma proteins, red blood cells, or stored glycogen

C. As oxygenated haemoglobin, glucose, or dissolved nitrogen

D. As carbonic acid crystals, oxygen ions, or bound glucose

Answer: (A)

Explanation

Carbon dioxide travels in blood as bicarbonate ions, attached to haemoglobin as carbaminohaemoglobin, or dissolved in plasma. Oxygen transport by haemoglobin is a related process but does not describe the listed forms of carbon dioxide transport.

16. How do inhaled and exhaled air differ in gas composition?

A. Inhaled air contains less oxygen, while exhaled air contains less carbon dioxide

B. Inhaled air has more carbon dioxide, while exhaled air has more oxygen

C. Inhaled air has more oxygen, while exhaled air has more carbon dioxide

D. Both types of air contain nearly identical oxygen and carbon dioxide levels

Answer: (C)

Explanation

Inhaled air contains about 20% oxygen and almost no carbon dioxide, whereas exhaled air contains about 16% oxygen and 5% carbon dioxide. The other choices misrepresent the direction or size of these changes.

17. What respiratory response is expected when blood carbon dioxide levels rise?

A. Chemoreceptor activity increases while breathing becomes slower and shallower

B. Chemoreceptor activity decreases and breathing becomes slower and shallower

C. Chemoreceptor activity increases and breathing becomes deeper and faster

D. Chemoreceptor activity remains stable while oxygen binding stops

Answer: (C)

Explanation

Raised carbon dioxide activates chemoreceptors, increasing the depth and rate of breathing to remove more carbon dioxide. Slower, shallower breathing would tend to retain carbon dioxide rather than correct the rise.

18. A researcher investigates how nerve cells generate electrical signals and communicate chemically; which discipline best describes this work?

A. Physiology

B. Anatomy

C. Pathology

D. Pharmacology

Answer: (A)

Explanation

Physiology studies the functions and activities of living organisms and their parts, including physical and chemical processes. Anatomy would emphasize the structures of the nerve cells rather than their activity.

19. A vessel carries blood from the heart to the lungs for gas exchange. Which circuit does it belong to?

A. The coronary circuit

B. The lymphatic circuit

C. The systemic circuit

D. The pulmonary circuit

Answer: (D)

Explanation

The pulmonary circuit carries blood between the heart and lungs. The systemic circuit serves the rest of the body, while the other named circuits do not match this heart-to-lung pathway.

20. Which antibody and antigen pattern characterizes blood type AB?

A. A antigens with anti-B antibodies and no anti-A antibodies

B. Both A and B antigens with no anti-A or anti-B antibodies

C. B antigens with anti-A antibodies and no anti-B antibodies

D. No A or B antigens with both anti-A and anti-B antibodies

Answer: (B)

Explanation

Type AB blood has both A and B antigens and lacks anti-A and anti-B antibodies. Type O has neither antigen but both antibodies, whereas types A and B each have one antigen and the antibody against the other.

21. Which combination lists conditions that homeostatic control helps keep within normal limits?

A. Body temperature, blood pH, and blood glucose

B. Tooth number, body height, and genetic sequence

C. Lung shape, eye color, and fingerprint pattern

D. Bone length, hair color, and blood type

Answer: (A)

Explanation

Homeostatic control regulates variables such as temperature, fluid and electrolyte balance, blood pH, blood pressure, and blood glucose. The other combinations describe traits that are not the primary regulated variables listed here.

22. What sequence best describes haemostasis after a blood vessel is damaged?

A. Plasma leakage, white-cell division, platelet circulation, and artery expansion

B. Vessel dilation, red-cell division, antibody release, and plasma removal

C. Platelet destruction, collagen covering, vessel relaxation, and clot dissolution

D. Collagen exposure, platelet attachment and recruitment, plug formation, and vessel constriction

Answer: (D)

Explanation

Damage exposes collagen, causing platelets to attach and recruit additional platelets, form a plug, and release serotonin that constricts the vessel. The other sequences omit or reverse the central steps of this positive feedback process.

23. How does the intrinsic conduction system coordinate the heartbeat?

A. It controls heartbeat through lymphatic valves and skeletal muscle movement

B. It exchanges oxygen through the pulmonary circuit before each contraction

C. It conducts impulses through the SA node, AV node, AV bundle, and Purkinje fibres

D. It moves blood through the heart by alternating pressure in the arteries

Answer: (C)

Explanation

The intrinsic conduction system uses the sinoatrial node, atrioventricular node, atrioventricular bundle, and Purkinje fibres to coordinate atrial and ventricular contractions. The other processes describe circulation or lymph movement rather than electrical coordination.

24. Why does the left lung have two lobes while the right lung has three?

A. The right lung has a larger surface for gas exchange

B. The left lung has a cardiac notch for the heart

C. The right lung receives less blood from the heart

D. The left lung contains fewer bronchi for air passage

Answer: (B)

Explanation

The cardiac notch occupies space in the left lung, leaving it with two lobes compared with three in the right lung. Differences in bronchi or blood flow do not explain the lobe arrangement.

25. Which sequence correctly orders the six levels of biological organisation from simplest to most complex?

A. Chemical, cellular, tissue, organ, system, organism

B. Cellular, chemical, organ, tissue, organism, system

C. Chemical, tissue, cellular, system, organ, organism

D. Organism, system, organ, tissue, cellular, chemical

Answer: (A)

Explanation

The levels progress from chemical components to cells, tissues, organs, organ systems, and finally the organism. A tissue comes after the cellular level, not before it.

26. Which list contains the four primary tissue types?

A. Skeletal, cardiac, smooth, and glandular

B. Bone, blood, cartilage, and adipose

C. Neuronal, epithelial, vascular, and muscular

D. Epithelial, connective, muscle, and nervous

Answer: (D)

Explanation

The four primary tissue types are epithelial, connective, muscle, and nervous tissue. Skeletal, cardiac, and smooth are subtypes of muscle tissue rather than the complete set of primary tissue categories.

27. Which structure belongs to the lower respiratory tract?

A. The pharynx

B. A bronchiole

C. The oral cavity

D. The nasal cavity

Answer: (B)

Explanation

The lower respiratory tract includes the trachea, bronchi, bronchioles, and alveoli. The nasal cavity, oral cavity, and pharynx are parts of the upper respiratory tract.

28. Which set correctly lists the four chambers of the heart?

A. Right atrium, left atrium, right ventricle, left ventricle

B. Right atrium, left atrium, pulmonary artery, left ventricle

C. Right ventricle, left ventricle, aorta, pulmonary vein

D. Right atrium, right ventricle, vena cava, left ventricle

Answer: (A)

Explanation

The heart has two atria and two ventricles: the right and left atria, and the right and left ventricles. The other choices replace one chamber with a blood vessel.

29. What feature of haemoglobin explains cooperative oxygen binding?

A. Each haemoglobin subunit carries several oxygen molecules on one iron atom

B. Binding one oxygen molecule makes binding easier for the remaining sites

C. Binding one oxygen molecule blocks the remaining sites from accepting oxygen

D. Carbon dioxide binding causes haemoglobin to release oxygen progressively

Answer: (B)

Explanation

Each haemoglobin subunit contains an iron atom that can bind one oxygen molecule, and binding increases the ease of binding at the remaining sites. The alternatives describe blocked binding, incorrect iron capacity, or a different transport relationship.