Biology Test Practice Test: Video 5 Answers (25 Questions) — Questions and Answers

Question 1: Which plant hormone promotes cell elongation and is produced primarily in shoot apical meristems?

Abscisic acid
Auxin (IAA) (Correct answer)
Cytokinin
Gibberellin

Correct answer: Auxin (IAA)

Auxin (indole-3-acetic acid) is produced in shoot tips and promotes cell elongation by loosening cell walls, driving phototropic and gravitropic responses.

Question 2: Which plant structure stores food reserves in a seed and nourishes the embryo during germination?

Testa
Micropyle
Endosperm (Correct answer)
Cotyledon

Correct answer: Endosperm

The endosperm is a nutrient-rich tissue in seeds that provides energy and nutrients to the developing embryo during germination.

Question 3: In C4 plants, where does initial CO2 fixation occur?

Epidermal cells
Mesophyll cells (Correct answer)
Guard cells
Bundle sheath cells

Correct answer: Mesophyll cells

In C4 plants, CO2 is initially fixed in mesophyll cells into a 4-carbon compound before being transferred to bundle sheath cells for the Calvin cycle.

Question 4: What structure regulates gas exchange in plant leaves?

Cuticle
Stomata (Correct answer)
Lenticels
Trichomes

Correct answer: Stomata

Stomata are pores in the leaf epidermis flanked by guard cells that open and close to regulate CO2 intake and water vapor loss.

Question 5: Which molecule serves as the primary energy currency of the cell?

ADP
ATP (Correct answer)
NADH
GTP

Correct answer: ATP

ATP (adenosine triphosphate) stores and transfers chemical energy for cellular processes.

Question 6: Which vitamin is a precursor to the coenzyme NAD+?

Vitamin C
Vitamin B12
Vitamin B3 (Niacin) (Correct answer)
Vitamin D

Correct answer: Vitamin B3 (Niacin)

Niacin (vitamin B3) is the dietary precursor used by cells to synthesize NAD+ and NADP+.

Question 7: Which molecule is the final electron acceptor in aerobic respiration?

ADP
Carbon dioxide
NAD+
Oxygen (Correct answer)

Correct answer: Oxygen

Oxygen accepts electrons at Complex IV (cytochrome c oxidase) and combines with protons to form water.

Question 8: Which structure in the ear converts sound vibrations into nerve impulses?

Organ of Corti (Correct answer)
Eustachian tube
Tympanic membrane
Semicircular canals

Correct answer: Organ of Corti

The organ of Corti, located within the cochlea, contains hair cells that transduce fluid vibrations into electrical signals transmitted via the cochlear nerve.

Question 9: Which blood vessel carries oxygenated blood away from the lungs to the heart?

Superior vena cava
Pulmonary artery
Pulmonary vein (Correct answer)
Aorta

Correct answer: Pulmonary vein

The pulmonary veins (four total) carry freshly oxygenated blood from the lungs to the left atrium of the heart.

Question 10: Which hormone stimulates the reabsorption of sodium ions in the renal tubule, thereby regulating blood pressure?

Cortisol
Atrial natriuretic peptide (ANP)
Aldosterone (Correct answer)
Antidiuretic hormone (ADH)

Correct answer: Aldosterone

Aldosterone, secreted by the adrenal cortex, acts on the distal tubule and collecting duct to increase Na⁺ reabsorption and K⁺ excretion.

Question 11: What part of the brain controls voluntary movements?

Cerebellum
Hypothalamus
Medulla oblongata
Cerebrum (Correct answer)

Correct answer: Cerebrum

The cerebrum is the largest and most anterior part of the brain, responsible for higher-level functions including voluntary movements, thought, language, memory, and sensory processing. Its outer layer, the cerebral cortex, is highly folded to increase surface area, facilitating complex cognitive activities and conscious control.

Question 12: What is the primary purpose of red blood cells?

Producing hormones
Carrying oxygen (Correct answer)
Clotting blood
Fighting infections

Correct answer: Carrying oxygen

Red blood cells, also known as erythrocytes, are specialized cells in the blood whose primary function is to transport oxygen from the lungs to the body's tissues. They contain hemoglobin, a protein that binds reversibly with oxygen, enabling efficient oxygen delivery and carbon dioxide transport back to the lungs.

Question 13: What is the basic functional unit of the nervous system?

Neuron (Correct answer)
Synapse
Myelin sheath
Glial cell

Correct answer: Neuron

Neurons are specialized cells that transmit electrical and chemical signals throughout the nervous system, forming the basis of all neural communication.

Question 14: What is the function of the myelin sheath?

To connect neurons to muscles
To generate nerve impulses
To store neurotransmitters
To insulate nerve fibers and speed up signal transmission (Correct answer)

Correct answer: To insulate nerve fibers and speed up signal transmission

The myelin sheath is a fatty insulating layer that wraps around axons, dramatically increasing the speed of electrical signal conduction through saltatory conduction.

Question 15: Which part of the brain is responsible for voluntary movement?

Motor cortex (frontal lobe) (Correct answer)
Temporal lobe
Brain stem
Occipital lobe

Correct answer: Motor cortex (frontal lobe)

The motor cortex, located in the frontal lobe, plans and executes voluntary movements by sending signals down the spinal cord to muscles.

Question 16: What happens at a synapse?

DNA is exchanged between cells
Blood flows between neurons
Neurons physically touch each other
Chemical neurotransmitters transmit signals between neurons (Correct answer)

Correct answer: Chemical neurotransmitters transmit signals between neurons

At a synapse, electrical signals trigger the release of neurotransmitters from the presynaptic neuron across the synaptic cleft, binding to receptors on the postsynaptic neuron.

Question 17: What is a neurotransmitter?

A brain structure
A chemical messenger that transmits signals across synapses (Correct answer)
A type of neuron
An electrical impulse

Correct answer: A chemical messenger that transmits signals across synapses

Neurotransmitters are chemical substances (like dopamine, serotonin, and acetylcholine) released by neurons to transmit signals to other neurons, muscles, or glands.

Question 18: What is the primary function of the kidneys?

Exchanging oxygen.
Pumping blood.
Filtering waste and regulating fluids (Correct answer)
Producing insulin.

Correct answer: Filtering waste and regulating fluids

The kidneys are vital organs responsible for filtering waste products, toxins, and excess water from the blood to form urine. They also play a critical role in regulating blood pressure, electrolyte balance, and red blood cell production. This ensures the body's internal environment remains stable and healthy.

Question 19: Which system is responsible for producing hormones?

Nervous system.
Endocrine system (Correct answer)
Respiratory system.
Muscular system.

Correct answer: Endocrine system

The endocrine system is a network of glands that produce and secrete hormones, which are chemical messengers. These hormones regulate a wide range of bodily functions, including metabolism, growth, reproduction, and mood. It works in conjunction with the nervous system to maintain homeostasis.

Question 20: What is the function of the skeletal system?

Pumping blood.
Digesting food.
Providing structure and protecting organs (Correct answer)
Producing hormones.

Correct answer: Providing structure and protecting organs

The skeletal system provides the body with its fundamental framework, giving it shape and support. It also plays a crucial role in protecting vital internal organs from injury, such as the brain and heart. Beyond structure, bones also store minerals and produce blood cells.

Question 21: What is the role of the muscular system?

Producing red blood cells.
Facilitating movement and maintaining posture (Correct answer)
Exchanging gases.
Digesting food.

Correct answer: Facilitating movement and maintaining posture

The muscular system is primarily responsible for all types of body movement, from walking and lifting to the involuntary actions of internal organs. Muscles contract and relax, pulling on bones to create motion and also maintaining posture against gravity. This system is essential for both voluntary and involuntary bodily functions.

Question 22: What is the main function of the circulatory system?

Breaking down food.
Transporting blood and nutrients (Correct answer)
Producing hormones.
Controlling body movement.

Correct answer: Transporting blood and nutrients

The circulatory system, comprising the heart, blood vessels, and blood, is responsible for transporting vital substances throughout the body. It delivers oxygen and nutrients to cells, while simultaneously carrying away waste products like carbon dioxide. This continuous circulation is essential for maintaining cellular function and overall body health.

Question 23: Which microorganism is used in the production of bread and alcoholic beverages?

Bacteria
Virus
Algae
Yeast (Correct answer)

Correct answer: Yeast

Yeast, specifically *Saccharomyces cerevisiae*, is a single-celled fungus crucial in the production of bread and alcoholic beverages. In bread making, yeast ferments sugars to produce carbon dioxide, which causes the dough to rise, while in brewing, it ferments sugars into ethanol and carbon dioxide, creating alcohol.

Question 24: Which genetic engineering tool allows precise editing of DNA sequences?

Polymerase Chain Reaction (PCR)
Gel Electrophoresis
CRISPR-Cas9 (Correct answer)
Southern Blot

Correct answer: CRISPR-Cas9

CRISPR-Cas9 is a revolutionary genetic engineering tool that allows scientists to precisely edit DNA sequences in living organisms. It uses a guide RNA to locate specific DNA targets and a Cas9 enzyme to cut the DNA, enabling the insertion, deletion, or modification of genes with high accuracy and efficiency.

Question 25: What is the primary purpose of antibiotics?

To provide energy to cells
To kill viruses
To kill or inhibit bacteria (Correct answer)
To boost the immune system

Correct answer: To kill or inhibit bacteria

Antibiotics are a class of antimicrobial drugs specifically designed to combat bacterial infections. They work by either killing bacteria directly (bactericidal) or inhibiting their growth and reproduction (bacteriostatic), targeting bacterial-specific processes without significantly harming human host cells.

Biology Test Practice Test: Video 5 Answers (25 Questions)

Which plant hormone promotes cell elongation and is produced primarily in shoot apical meristems?

What Practice Test Geeks adds beyond an AI chat for Biology

An AI chatbot can quiz you, but it can't reproduce the exam conditions or keep your record. Here you get:

A timed, full-length Biology mock exam — 115 questions in 90 minutes with a 50% pass mark, modeled on the official exam's question count and time limit, followed by a score report broken down by exam domain.
A fixed Biology question bank: the same test every attempt, so your score is comparable from one try to the next instead of changing with every regenerated quiz.
Progress saved on your device: completed tests, scores and missed questions stay in My Progress, so you can retake only what you got wrong.
A printable Biology cheat sheet you can print or save as a PDF.
Biology flashcards built from the same question bank.

Start the Timed Biology Mock Exam →

These practice questions were written with AI tools. They are not real exam questions. We have not yet matched this exam's facts to an official source, so confirm fees, dates and rules with the exam body. Not reviewed by a subject-matter expert. Editorial policy