After an action potential, what channel opens to reset the electrical gradient?

	a. Sodium
	b. Potassium
	c. Chloride
	d. Bicarbonate

.

Ahmed's doctor is concerned about his heart and orders an electrocardiogram. During the test, Ahmed's doctor notices a big spike that reappears over and over between two smaller humps. What does this spike most likely represent?

	a. The atria pumping blood into ventricles
	b. Depolarization of papillary muscles
	c. Repolarization of ventricles
	d. Depolarization of ventricles

.

Bicarbonate based drugs neutralize the secretions from which of the following cell types?

	a. Chief cells
	b. G-cells
	c. Mucus cells
	d. Parietal cells

.

Blood enters the stomach as the result of a bleeding ulcer and blood enzyme X no longer functions. Which of the following is the most likely the reason for enzyme X's loss of function?

	a. There is a much greater hydrogen ion concentration in the stomach.
	b. The stomach has a much higher temperature, because it is deep into the superficial blood vessels.
	c. The concentration of substrate is less in the stomach.
	d. There is more salt in the stomach due to dietary intake.

.

Candice has a low libido and her doctor mentions low hormone levels. Which of the following is most likely decreased in Candice, causing this problem?

	a. Estrogen
	b. Progesterone
	c. FSH
	d. Testosterone

.

Carol is concerned that her menstrual cycle is too short, because she gets her period every 15 days. Are Carol's concerns valid? Why, or why not?

	a. No, her concerns are not valid, because the average length of a menstrual cycle is 12 days.
	b. No, her concerns are not valid, because the average length of a menstrual cycle is 5 days.
	c. No, her concerns are not valid, because her menstrual cycle is close to the average of 14 days.
	d. Yes, her concerns are valid, because her cycle falls short of the average 28 days.

.

Cellular respiration occurs in which of the following orders?

	a. Glycolysis, Krebs cycle, and electron transport chain
	b. Glycogenolysis, Krebs cycle, and electron transport chain
	c. Glycolysis, photosynthesis, and electron transport chain
	d. Glycogenolysis, electron transport chain, and Krebs cycle

.

Choose the best answer to fill in the blanks. A scientist designs a study to investigate the relationship between heart rate and physical activity in 25 subjects. The results indicate that heart rate increased significantly following 20 minutes of physical activity. In this experiment, the dependent variable is ______________ and the independent variable is _______________.

	a. heart rate, physical activity
	b. physical activity, heart rate
	c. heart rate, time
	d. subjects, heart rate

.

Donna has iron deficiency anemia and because of this has difficulty transporting oxygen. What cells are involved?

	a. Dust cells in the lungs
	b. Islet cells in the pancreas
	c. Epithelial cells in the skin
	d. Erythrocytes in the blood

.

Fill in the blanks. During a skeletal muscle contraction, ______________ released from the ______________ binds to troponin on the myofibrils, causing a conformational change allowing actin and myosin to indirectly bind and the muscle to contract.

	a. energy, mitochondria
	b. protein, Golgi apparatus
	c. calcium, sarcoplasmic reticulum
	d. acetylcholine, motor neuron

.

Gustatory receptors have been stimulated. What most likely caused this to happen?

	a. The smell of blooming flowers
	b. Tasty bacon
	c. A ringing phone
	d. The warmth of the sun

.

How are sperm cells carried from the ejaculatory duct to the urethra?

	a. Sperm cells are carried from the ejaculatory duct to the urethra by vas deferens.
	b. Sperm cells are not carried; instead, they move through the urethra by flagella.
	c. Sperm cells are carried by the secretion of a hormone from the prostate glands.
	d. Both B and C

.

How are type I diabetics different from type II diabetics?

	a. Type I diabetics produce insulin, and Type II diabetics do not.
	b. Type II diabetics have insulin resistant cells, but typically produce insulin.
	c. Type I diabetics have insulin resistant cells and do not produce insulin.
	d. Type II diabetics are always adults, whereas Type I diabetics are only children.

.

How do neutrophils destroy microorganisms?

	a. Phagocytosis of bacteria
	b. Destruction of virus infected cell
	c. Release of histamine granules
	d. Production of antibodies

.

How do smooth muscle contractions differ from those of skeletal muscle?

	a. Smooth muscle fatigues more quickly.
	b. Skeletal muscles contract slowly.
	c. Smooth muscles have long contractions.
	d. Skeletal muscle contractions are involuntary.

.

How does a sodium atom become charged?

	a. It loses an electron.
	b. It gains a proton.
	c. It gains an electron.
	d. It loses a proton.

.

How does HIV impact immune function?

	a. Cytotoxic T cells are infected and perform targeted killing.
	b. Helper T cells are infected and cannot stimulate immune response.
	c. B cells are infected and cannot produce antibodies.
	d. Neutrophils are infected and cannot engulf virus.

.

How does insulin work with glucagon to regulate blood glucose levels?

	a. Both are released to bring down elevated blood glucose.
	b. Glucagon regulates elevated blood glucose and insulin regulates low blood glucose.
	c. Insulin is released in response to elevated blood glucose and glucagon low blood glucose.
	d. Glucagon stimulates the liver to store blood glucose and insulin to use stored glucose.

.

How does the insulin receptor work to trigger a cell to take up glucose?

	a. It modifies the pH value of the plasma surrounding a cell.
	b. It carries glucose into the cell.
	c. It transfers a signal from outside to inside the cell but does not allow insulin to enter.
	d. It allows insulin to enter into the cell to signal to the cell.

.

How does the respiratory system affect the pH of blood?

	a. It does not affect the pH.
	b. It regulates the pH by allowing oxygen into the blood, which has a neutralizing effect.
	c. Increased breathing rate allows blood to pump through the heart faster.
	d. Carbon dioxide in the blood acts as one part of a buffering system and lowers the pH as needed.

.

How is a change in equilibrium detected by the ear?

	a. Cerumen moves to accommodate the change in position.
	b. Otoliths shift with positional changes.
	c. The stapes and anvil transmit vibrations.
	d. Fluid builds up behind the tympanic membrane.

.

Individuals living in third world countries often have an enlargement of the thyroid gland known as a goiter. What mineral is missing from their diet that leads to this enlargement? Hint: This mineral is required to make thyroxine.

	a. Tyrosine
	b. Iodine
	c. Cortisol
	d. Magnesium

.

Jack and Jill really want a daughter. They know that the sperm determines the sex of a baby. What chromosome must Jack's sperm contain for the offspring to be female?

	a. A
	b. Y
	c. X
	d. B

.

Jack is lactose intolerant, which means he cannot break down the milk sugar lactose into the simple sugars glucose and galactose to be absorbed. Where in the gastrointestinal track would glucose and galactose normally be absorbed?

	a. Stomach
	b. Saliva
	c. Small intestine
	d. Large intestine

.

Jan is going on a trip outside the country next week and wants to ensure that she will not get sick from her travels. Her doctor suggests passive immunity. How will Jan get passive immunity?

	a. Exposure to pathogen and subsequent creation of antibodies
	b. Vaccinations
	c. Injection of antibodies created by another human or animal
	d. Inhalation of pathogens

.

Lucy, an adult female, has her blood pressure checked and learns that it is 80/80 mmHg. Which of the following is true of Lucy's blood pressure?

	a. She has high systolic pressure.
	b. She has high diastolic pressure.
	c. She has low systolic pressure.
	d. She has low diastolic pressure.

.

Most cells contain a nucleus, cytoplasm, and a cell membrane. Which of the following cell types do not contain a nucleus?

	a. Neurons
	b. Skeletal muscle cells
	c. Cuboidal cells
	d. Mature red blood cells

.

Myrtle is told that she has a small bladder. What does this mean for Myrtle?

	a. She is not able to produce enough blood.
	b. She is able to store a lot of urine in her body.
	c. She can easily lose weight.
	d. She is not able to store a lot of urine in her body.

.

Nancy thinks that she is pregnant. What is the name of the hormone that is detected in pregnancy tests that is released from the placenta?

	a. Oxytocin
	b. FSH
	c. LH
	d. HCG

.

Nita had her gallbladder removed. Why must she avoid certain foods?

	a. She does not produce enough bile to absorb large quantities of lipid.
	b. She does not produce enough insulin to take up glucose from her blood.
	c. She does not produce lactase to digest milk products.
	d. She does not produce enough saliva to emulsify her food completely.

.

Ovulation is stimulated by a mid-cycle hormone surge. Which hormone is elevated to trigger egg release?

	a. FSH
	b. Estrogen
	c. LH
	d. Progesterone

.

Patients with chronic obstructive pulmonary disorder (COPD) often have difficulty breathing and may become hypoxic. What does this mean?

	a. High carbon dioxide concentration
	b. Low oxygen concentration
	c. High oxygen concentration
	d. Low carbon dioxide concentration

.

Sally is having difficulty losing weight. She has noticed that her skin is dry, and she is tired all the time. Her doctor suspects that her thyroxine levels are low and is going to run a screening test for the hormone released from the pituitary that stimulates the thyroid gland to make thyroxine. What test will Sally's doctor order?

	a. ADH
	b. TSH
	c. LH
	d. ACTH

.

Sandy has difficult with constipation. Where in the gastrointestinal track is water reabsorbed from solid waste, making her constipation worse?

	a. Stomach
	b. Jejunum
	c. Small intestine
	d. Large intestine

.

Smooth muscle lining the gastrointestinal track propels foodstuff forward. What is this movement called?

	a. Absorption
	b. Excretion
	c. Reabsorption
	d. Peristalsis

.

Susana drank a lot of coffee this morning and blames the caffeine in it for her frequent trips to the bathroom. What hormone, which controls water excretion in the kidneys, does caffeine block?

	a. Oxytocin
	b. Prolactin
	c. ACTH
	d. ADH

.

The carbon and hydrogen atoms in a glucose molecule are covalently bonded. What does this mean?

	a. Electrons are shared between carbon and hydrogen.
	b. Electrons are transferred between carbon and hydrogen.
	c. Protons are shared between carbon and hydrogen.
	d. Protons are transferred between carbon and hydrogen.

.

The dendrites send graded potentials to the soma. What happens to the resting membrane potential (-70 mVolts) in the cell as a result of these graded potentials?

	a. The cell goes from -70 mVolts to less negative.
	b. The cell goes from -70 mVolts to positive.
	c. The cell goes from +30 mVolts to 0 mVolts.
	d. The cell goes from +30 mVolts to +70 mVolts.

.

The Periodic Table of Elements is used to find information to describe atomic structure, which is important to know to describe atomic interactions in physiology. If you were going to describe the structure of potassium, what atomic symbol would you find it listed under on the table?

	a. K
	b. P
	c. C
	d. Na

.

Waste products have built up in the blood, resulting from a loss of homeostasis due to organ failure. Which of the following systems is most likely involved in this example?

	a. Respiratory
	b. Digestive
	c. Endocrine
	d. Urinary

.

What are the products of cellular respiration?

	a. Glucose and water
	b. Carbon dioxide and water
	c. Glucose and carbon dioxide
	d. Water and oxygen

.

What division of the nervous system includes the autonomic nervous system involved in involuntary activity?

	a. Central
	b. Somatic
	c. Sensory
	d. Peripheral

.

What happens during an isometric muscle contraction?

	a. Tension stays the same, but the muscle shortens.
	b. Tension increases, and the muscle elongates.
	c. Tension increases, but the muscle does not shorten.
	d. Tension stays the same, and muscle length stays the same.

.

What happens during the depolarization phase of an action potential?

	a. During the depolarization phase, there is a release of calcium ions.
	b. During the depolarization phase, there is an inflow of sodium ions.
	c. During the depolarization phase, the potassium channels close.
	d. During the depolarization phase, there is an inflow of potassium ions.

.

What is a key difference between pre-mRNA and mRNA used to make proteins?

	a. pre-mRNA has been spliced, whereas mRNA has not been spliced.
	b. mRNA contains both introns and exons, whereas pre-mRNA does not have introns and exons.
	c. mRNA has extra coding regions, whereas pre-mRNA does not have these extra coding regions.
	d. mRNA has had its introns removed, whereas pre-mRNA has introns.

.

What is an advantage of the Nodes of Ranvier?

	a. Less energy is required to repolarize after the action potential.
	b. Signaling in the neuron slows down and becomes more focused.
	c. Myelin insulates the area preventing signal loss.
	d. Only one Node is required per neuron.

.

What is the function of an erythrocyte?

	a. To fight infection
	b. To stop bleeding
	c. To carry oxygen
	d. To transport hormones

.

What is the main function of proximal tubule?

	a. Reabsorption
	b. Excretion
	c. Secretion
	d. Filtration

.

What is the name of the hormone that controls sodium reabsorption and potassium secretion?

	a. Oxytocin
	b. Prolactin
	c. ACTH
	d. Aldosterone

.

What is the role of the pancreas in digestion?

	a. To secrete bile
	b. To secrete digestive enzymes, principally to digest lipids and protein
	c. To balance the pH in the blood
	d. To serve as a shelter for intestinal microflora and bacteria

.

What is the vital capacity of the lungs?

	a. The amount of air moved in and out of the lungs during normal breathing
	b. The total of tidal, inspiratory reserve, and expiratory reserve capacities
	c. The amount of air moved in and out of the lungs during deep breathing
	d. The excess air in the lungs

.

What is true of the hormones secreted from the adrenal gland?

	a. They stimulate inflammation.
	b. They stimulate the kidneys to dump sodium.
	c. They stimulate the blood vessels to constrict.
	d. They have a major role in reproductive function.

.

What is unique about cardiac muscle?

	a. Individual spindle shape cells contract in long rhythmic contractions.
	b. Cells connect to one another to contract together as a single unit.
	c. Long cells have multiple nuclei that regulate contraction.
	d. Voluntary stimulation is necessary to facilitate contraction.

.

What role do lymph nodes play in immune function?

	a. Lymph nodes produce white blood cells.
	b. All white blood cells must go to the lymph nodes to be activated.
	c. Lymph nodes filter lymph fluid to remove microorganisms from lymphatic circulation.
	d. Lymph nodes route white blood cells through the body.

.

When odorants enter the nose, what happens to them?

	a. They combine with mucous.
	b. They bind to receptors.
	c. They get exhaled.
	d. They are destroyed.

.

Where does Krebs cycle occur?

	a. Mitochondria
	b. Rough ER
	c. Smooth ER
	d. Nucleus

.

Which of the following are the main parts of the peripheral nervous system involved in input and output with the central nervous system?

	a. Afferent and efferent divisions
	b. Sympathetic and parasympathetic nervous systems
	c. Efferent division and central nervous system
	d. Brain and the spinal cord

.

Which of the following best describes active labor?

	a. The baby moves through the birth canal.
	b. Contractions are mild and not necessarily regular.
	c. The bag of waters break.
	d. The urge to push is present.

.

Which of the following best describes digestion?

	a. Absorption through small intestine
	b. Excretion from the colon
	c. Enzymatic and chemical breakdown of food
	d. Mixing of the food

.

Which of the following best describes how signals from the limbs are consciously identified?

	a. Sensory neurons route directly from the limb to the cortex.
	b. Sensory neurons route through spinal cord ascending tracts to the thalamus and then cortex.
	c. Sensory neurons route directly to the thalamus from the limb.
	d. Sensory neurons route through spinal cord ascending tracts to the cortex and then the thalamus.

.

Which of the following best describes systolic pressure of the blood?

	a. Peak pressure of the blood on the walls of the arteries during the cardiac cycle
	b. Lowest pressure of the blood on the walls of the arteries during the cardiac cycle
	c. The response pressure of the blood to a stimulus
	d. The pressure of the blood against the capillaries during the cardiac cycle

.

Which of the following describes active transport?

	a. Sucrose dissolving in hot coffee
	b. Sodium moving through a sodium channel
	c. Water moving across a cell membrane
	d. Potassium being pumped into a cell

.

Which of the following describes paracrine activity?

	a. Factors must travel through the blood to find target receptors.
	b. Factors produced in a cell act on that cell.
	c. Factors released from a cell act on adjacent cells.
	d. None of these answers

.

Which of the following describes the anabolism of a macromolecule carried out by body cells?

	a. Polypeptides undergo hydration to generate amino acids.
	b. Glycogen breaks down to release glucose.
	c. Fats are digested by lipase into constituent fatty acids.
	d. Nucleotides undergo dehydration synthesis to produce DNA.

.

Which of the following describes the central nervous system's role in the coordination of skeletal muscle movements?

	a. The cerebellum compares information received from sensory inputs to that received from the cerebral cortex.
	b. The medulla oblongata uses reflex activity to regulate regular muscle activity.
	c. The thalamus routes all muscle activity through the pituitary gland.
	d. The hypothalamus senses changes in muscle movement.

.

Which of the following is an autoimmune disease where the pancreas is unable to produce insulin?

	a. Acromegaly
	b. Fibromyalgia
	c. Diabetes insipidus
	d. Type I Diabetes mellitus

.

Which of the following is an example of a peptide bond?

	a. Sodium and chloride are attracted to one another because of opposite charge.
	b. Water molecules are attracted to one another because of charged ends.
	c. Lysine and arginine bond to one another through carboxyl and amino groups.
	d. Carbon and hydrogen bond to one another to create methane.

.

Which of the following is an example of exocytosis?

	a. Water moving across the cell membrane
	b. Hormones leaving the cell via vesicle fusion with the membrane
	c. Potassium transportation using a pump
	d. Glucose entry into the cell as a result of insulin

.

Which of the following is NOT a function of the kidneys?

	a. To respond to changing water levels in the body
	b. To regulate sodium levels in the blood
	c. To produce cortisol
	d. To remove urea from the blood

.

Which of the following is NOT an example of a negative feedback loop?

	a. Blood glucose increases, leading to insulin release and causing blood glucose to decrease.
	b. Body temperature decreases, so muscle cells contract, causing shivering and increasing body temperature.
	c. Uterine contractions continuously increase during pregnancy until delivery.
	d. Thyroid hormones are elevated, leading to a decrease in TSH and in turn a decrease in thyroid hormone release.

.

Which of the following is not an example of a sympathetic response?

	a. Increased blood glucose
	b. Elevated cardiac output
	c. Bronchoconstriction
	d. Blood flow diverted to muscles

.

Which of the following receptor types in the heart is blocked by specific drugs used to prevent hypertension?

	a. Beta
	b. Muscarinic
	c. Nicotinic
	d. Epsilon

.

Which of the following scenarios is an example of endocrine system function?

	a. Erythrocytes carrying oxygen to the tissues
	b. Neutrophils phagocytizing bacteria
	c. Motor neurons signaling to skeletal muscle
	d. Aldosterone stimulating the kidneys to save sodium

.

Which of the following statements best describe the function of veins?

	a. Veins are blood vessels that carry blood out of the heart.
	b. Veins are blood vessels that exchange nutrients.
	c. Veins are blood vessels that always carry oxygenated blood.
	d. Veins are blood vessels that return blood to the heart.

.

Which of the following statements best describes how the sodium-potassium ATPase pump functions?

	a. It moves sodium into a cell and potassium out.
	b. It moves potassium into a cell and sodium out.
	c. It moves both sodium and potassium into a cell.
	d. It moves both sodium and potassium out of a cell.

.

Which of the following statements best describes the function of arteries?

	a. Arteries are blood vessels that carry blood out of the heart.
	b. Arteries are blood vessels that exchange nutrients.
	c. Arteries are blood vessels that always carry oxygenated blood.
	d. Arteries are blood vessels that always carry deoxygenated blood.

.

Which of the following statements is true of the electrons found in the components of table salt that allow it to stay bonded?

	a. Electrons are shared.
	b. Electrons are transferred.
	c. Electrons are destroyed.
	d. Electrons are changed.

.

Which of the following statements is true of the upper respiratory tract?

	a. It increases the amount of air that the lungs can take in.
	b. It only functions to detect odorants and pheromones in the air.
	c. It is a functional preadaptation due to the established form of the head and neck.
	d. It filters dust and pathogens from the air.

.

Which of the following will be impacted if hair cells are damaged?

	a. Balance
	b. Hearing
	c. Sight
	d. Both balance and hearing

.

Which order does the pulmonary blood circulation follow?

	a. Right atrium, right ventricle, pulmonary artery, pulmonary vein, left atrium, and left ventricle
	b. Left atrium, left ventricle, pulmonary artery, pulmonary vein, right atrium, and right ventricle
	c. Left atrium, left ventricle, pulmonary vein, right atrium, and right ventricle
	d. Right atrium, right ventricle, pulmonary artery, left atrium, and left ventricle

.

You are a pharmacologist designing Drug XYZ. You want it to interfere with enzyme activity by interfering with substrate binding. What site will you target?

	a. Active site
	b. Deactivation site
	c. Energy site
	d. Substrate site

.

You are a scientist tasked with testing the effects of the active ingredient in a new drug, known as Drug X. Which of the following groups will serve as a control to best identify whether the effects of Drug X can truly be attributed to the active ingredient in Drug X?

	a. 10 individuals treated once a day with Drug X
	b. 10 individuals treated twice a day with Drug X
	c. 10 individuals treated with a placebo drug
	d. 10 individuals who have not been treated with Drug X or placebo

.

You are walking through the woods and meet a bear. Which of the following is most likely to be released in large quantities in your blood?

	a. GABA
	b. Glutamine
	c. Acetylcholine
	d. Epinephrine

.

Your friend has been having acid reflux and is taking antacids to help with the problem. How does an antacid change the pH of the stomach?

	a. Antacids increase stomach pH.
	b. Antacids decrease stomach pH.
	c. The net effect of antacids is that stomach pH stays the same.
	d. Antacids do not alter stomach pH.

.

Your muscles need to contract and must be stimulated. How will the muscles be signaling to contract?

	a. Acetylcholine will be released from the motor neuron into the synaptic cleft.
	b. Neurons will release calcium into transverse tubules of the muscle fiber.
	c. Stimulatory neurons will create a synapse with the muscle fiber by touching it.
	d. Sensory neurons will touch the end of a muscle fiber causing a synaptic signal.

.

A woman is in labor and is experiencing strong uterine contractions. What hormone is being released and from what gland?

	a. Oxytocin is released from the adrenal glands.
	b. Vasopressin is released from the anterior pituitary.
	c. Oxytocin is released from the posterior pituitary.
	d. Calcitonin is released from the parathyroid glands.

.

Blood pH is 7.30 as a result of hyperventilation. Which of the following mechanisms would the body use to return to homeostasis?

	a. Increased breathing to get more oxygen into the lungs
	b. Shallow breathing to minimize loss of carbon dioxide
	c. Increased urine output of bicarbonate
	d. The saving of hydrogen ion in the kidneys

.

Choose the best answer to fill in the blanks. During respiration, a contraction of the diaphragm causes the muscle to move ______________, and the thoracic cavity to ______________.

	a. upward toward the head, expand
	b. upward toward the head, contract
	c. downward toward the feet, expand
	d. downward toward the feet, contract

.

Complete the following statement. The action potentials that initiate cardiac contraction are generated by specialized cells located in the:

	a. left ventricle.
	b. atrioventricular node.
	c. fibrillator.
	d. sinoatrial node.

.

During ovulation of an egg, how many chromosomes does the egg contain?

	a. 46
	b. 48
	c. 24
	d. 23

.

Frederick has problems with acid reflux and takes antacids to help with his symptoms. He wonders if his stomach should be acidic at all. What is the normal pH of the stomach?

	a. 3
	b. 6.8
	c. 7
	d. 7.4

.

Potassium channels open on a cell membrane. What happens to potassium?

	a. Potassium moves into the cell.
	b. Potassium moves out of the cell.
	c. Potassium stays where it is.
	d. Potassium follows sodium.

.

Stacy has glomerulonephritis (inflammation of the glomerulus). Which of the following will most likely and most directly be impacted?

	a. Nitrogenous waste removal from the blood
	b. Body water regulation
	c. Blood sodium and potassium levels
	d. Bacteria identification and destruction

.

Which of the following best describe catabolism?

	a. Catabolism is the synthesis of large molecules from smaller chemicals.
	b. Catabolism is the breakdown of larger molecules into smaller chemicals.
	c. Catabolism is synonymous with fat metabolism.
	d. Catabolism is synonymous with carbohydrate metabolism.

.

Which of the following best describes the function of interferons?

	a. They create holes in the membranes of foreign bodies.
	b. They engulf foreign bodies.
	c. They create blockades within lymphatic vessels.
	d. They inhibit viral growth and development.

.

Which of the following could happen if metaphase of mitosis was disrupted and not completed before telophase began?

	a. The nuclear envelope would not break down, and DNA would be lost.
	b. Two complete copies of DNA would not be created.
	c. Chromosomes may inappropriately split with one cell having more than the other.
	d. The cytoplasm would not pinch in leading to only one cell being created.

.

Which of the following describes what happens at the neuromuscular junction upon acetylcholine release into the synapse?

	a. Acetylcholine binds to its receptor and sodium ions flow into the muscle fiber.
	b. Acetylcholine binds to its receptor and calcium ions flow into the muscle fiber.
	c. Acetylcholine binds to its receptor and potassium ions flow into the muscle fiber.
	d. Acetylcholine binds to its receptor and chloride ions flow into the muscle fiber.

.

Which of the following is involved in the repolarization phase of an action potential?

	a. Release of calcium ions
	b. Inflow of sodium ions
	c. Closing of potassium channels
	d. Outflow of potassium ions

.

Which of the following is likely to stimulate a nociception?

	a. Applying a heating pad to the skin
	b. Contracting your muscles while lifting a weight
	c. Smelling food cooking
	d. Stepping on a nail

.

Which of the following is NOT an example of enzyme activity?

	a. Breaking down lactose into glucose and galactose using lactase
	b. Carbonic anhydrase converting water and carbon dioxide into bicarbonate
	c. Blocking cyclooxygenase using aspirin
	d. Catalase generating oxygen from peroxide

.