bio topic 6

Question 1

What is secreted by the pancreas for digestion in the small intestine?
A. Lipase to break bond between phosphate and fatty acid
B. Insulin to digest glycogen to glucose
C. Amylopectin to digest starch to maltose
D. Endopeptidase to digest proteins to peptides

Answer 1

D

Question 2

A fluid sample is taken from the digestive tract of a mammal. The sample is basic (alkaline) and able to digest starch and proteins. From which part of the digestive tract was the fluid taken?
A. Mouth
B. Stomach
C. Small intestine
D. Gall bladder

Answer 2

C

Question 3

Bacteria from chicken feces can cause a loss of intestinal villi in small children who happen to eat dirt in rural villages. Which effect could be expected from such a loss of villi?
A. Insufficient absorption of starch
B. Failure to digest dietary fibre
C. Malnutrition
D. An increase in microvilli

Answer 3

C

Question 4

Where is absorption of digested food carried out?
I. Villi
II. Pancreas
III. Small intestine
A. I only
B. I and II only
C. I and III only
D. I, II and III

Answer 4

C

Question 5

Where are lipids digested/broken donw in the human digestive system?

Answer 5

The small intestine

Question 6

What does amylase do?

Answer 6

Amylases digest starch into smaller molecules, ultimately yielding maltose, which in turn is cleaved into two glucose molecules by maltase.

Question 7

What does maltase do?

Answer 7

Maltase is an economically valuable enzyme that is used to catalyze the hydrolytic process of maltose and yields d-glucose as a product.

Question 8

What is glucosidase?

Answer 8

Glucosidases are the enzymes that are responsible for the hydrolytic breakdown of carbohydrates (starch, glycogen, and their disaccharides derivatives) into monomers.

Question 9

What does sucrase do?

Answer 9

Sucrase is an enzyme that hydrolyzes sucrose into its two component monosaccharides, glucose, and fructose.

Question 10

Where does digestion of polypeptides start in humans?

Answer 10

Stomach

Question 11

Which organ in the human body secretes lipase, amylase, ad protease?

Answer 11

Pancreas

Question 12

Glucose is absorbed through protein channels in the plasma membrane of epithelium cells in the small intestine. Which characteristics of glucose prevent its diffusion through the phospholipid bilayer?
A. It is non-polar and therefore hydrophobic.
B. Its hydrogen bonds link with amino acids in the protein channel.
C. It is polar and therefore hydrophilic.
D. Its covalent bonds interact with the phospholipids.

Answer 12

C

Question 13

In which process is “surface area” of key importance for humans?
A. Reabsorption of glucose in the proximal convoluted tubule
B. Release of surfactants by type I pneumocytes
C. Display of antibodies by red blood cells
D. Secretion of enzymes by villi of the small intestine

Answer 13

A

Question 14

What happens to starch in the small intestine?
A. Endopeptidase secreted by the liver digests starch to enable absorption by the villi.
B. Contraction of intestinal muscle mixes starch with enzymes to accelerate its conversion into amylose.
C. Glycogen secreted by the pancreas hydrolyses starch into glucose, which is eventually transported to the liver.
D. Amylase secreted by the pancreas digests starch to enable absorption by the villi.

Answer 14

D

Question 15

What are the functions of stomach, small intestine and large intestine?

Answer 15

Digest proteins, absorb glucose, absorb water

Question 16

What structure in the small intestine transport most fats?

Answer 16

Lacteals

Question 17

What are the source, substrate, and products of amylase?

Answer 17

Pancreas, starch, maltose

Question 18

Enzymes produced by the pancreas could pass out of the body via the anus. Which route would these enzymes take to do this?

Answer 18

pancreas -> small intestine -> large intestine -> anus

Question 19

Why do nutrient molecules enter the blood?

Answer 19

Blood carries the nutrients to cells

Question 20

What are features of amylase?

Answer 20

substrate is starch, source is salivary glands and optimum pH is 7

Question 21

Celiac disease causes the destruction of the villi cells. Which of the following is most likely to happen to people with celiac disease?
A. Incomplete digestion of fats
B. Poor absorption of calcium
C. Increased levels of glucose in blood
D. Damage in the esophagus caused by increase in acid content of the stomach

Answer 21

B

Question 22

What is an important function of lacteal?

Answer 22

Transport of fats

Question 23

Which parts of the digestive system secrete proteases?

Answer 23

Stomach and small intestine

Question 24

Where does most assimilation take place?
A. In cells
B. In the mouth
C. In the small intestine
D. In the large intestine

Answer 24

A

Question 25

Which characteristic of the subclavian vein distinguishes it from the subclavian artery? A. Larger lumen B. Absence of valves C. Presence of pores D. Two layers of muscle

Answer 25

A

Question 26

What happens during blood clotting? A. A chain reaction causes platelets to release antibodies to avoid infections. B. Thrombin is converted into fibrinogen after a series of chemical reactions. C. Sealing of wounds by fibrinogen makes platelets release antibodies for clotting. D. Chemical reactions cause wounds to seal after platelets release clotting factors.

Answer 26

D

Question 27

An individual was presented with a stimulus resulting in the release of epinephrine. What was the most likely nature of the stimulus? A. Sunset and the onset of darkness B. An image of a close friend C. The intake of glucose D. A coach shouting to begin physical activity

Answer 27

D

Question 28

When intense physical activity is anticipated, which factor in the blood will increase the frequency of sinoatrial signals to heart muscle? A. pH B. Oxygen level C. Thyroxin D. Epinephrine

Answer 28

D

Question 29

What happens in the heart when epinephrine is secreted into the blood? I. Pressure in the heart falls. II. The pulmonary artery transports oxygenated blood at a faster rate. III. The sinoatrial node increases the rate of electrical signals.

Answer 29

III only

Question 30

How are fats and cholesterol transported in the blood? A. As groups of molecules inside vesicles B. As individual molecules coated in phospholipids C. As individual molecules bound to a protein D. As groups of molecules in lipoprotein complexes

Answer 30

D

Question 31

What observation did William Harvey use as evidence for the circulation of blood?

Answer 31

Valves ensure unidirectional flow of blood

Question 32

What causes atrioventricular valves to close during a heartbeat?

Answer 32

Pressure in the atria is lower than in the ventricles

Question 33

What is a property of arteries?

Answer 33

Arteries have elastic walls

Question 34

What is a valid comparison between arteries and veins?

Answer 34

In arteries blood flows at high pressure, while in veins blood flows at lower pressure

Question 35

Which discovery was an indicator that the heart pumps blood to the body through arteries?

Answer 35

The heart swelled up when the arteries were tied in an animal experiment

Question 36

What is a feature of the human circulatory system? A. The wall of the right ventricle of the heart is the thickest of the four chambers. B. The pulmonary artery and vena cava both carry deoxygenated blood. C. Valves are found in arteries and veins but not capillaries. D. Epinephrine acts on the pacemaker to reduce heart rate.

Answer 36

B

Question 37

What is a role of the coronary arteries?

Answer 37

TO supply the heart muscle with nutrients and oxygen

Question 38

What causes heart ventricles to fill with blood?

Answer 38

The atrial contraction

Question 39

What are the conditions of blood travelling through the pulmonary vein?

Answer 39

Oxygen level: high, CO2 level: low, pressure: low

Question 40

What causes the heart rate increase or decrease?

Answer 40

Nerve impulses from the brain

Question 41

What is the function of thrombin in the process of blood clotting?

Answer 41

It acts as a catalyst

Question 42

What is a role of the pacemaker or sinoatrial node (SAN)? A. To initiate contraction of the ventricle B. To pass the excitation through Purkinje fibres C. To originate excitation in myogenic muscle D. To cause the relaxation of the atria

Answer 42

C

Question 43

In 1940, Florey and Chain tested penicillin on bacterial infections in eight mice, before treating a sick patient. Currently, what is the correct order for testing the effectiveness of an antibiotic or other drug? A. Affected patients, animals, healthy people B. Animals, healthy people, affected patients C. Healthy people, animals, affected patients D. Animals, affected patients, healthy people

Answer 43

B

Question 44

Some vaccinations, such as the smallpox vaccine, provide lifelong immunity against the disease. For others, such as tetanus, this immunity lasts for a shorter period of time. Why is a tetanus booster vaccination recommended every 10 years?

Answer 44

Memory cells gradually decline over 10 years

Question 45

Blood clotting involves a cascade of reactions. Which statement describes the blood-clotting process?

Answer 45

Fibrin forms a mesh that traps platelets and blood cells.

Question 46

Which statement applies to HIV?

Answer 46

HIV causes a reduction in production of antibodies

Question 47

How does HIV affect the immune system adversely?

Answer 47

Progressive reduction in number of active lymphocytes

Question 48

What is the role of antibiotics produced by fungi?

Answer 48

Inhibition of the growth of prokaryotes

Question 49

What are antibodies?

Answer 49

Antibodies are polypeptides

Question 50

Why are antibiotics effective against bacteria but not viruses? A. Viruses can hide inside host cells. B. Bacteria are recognized as pathogens but viruses are not. C. The enzymes of bacteria can be inhibited by antibiotics. D. Viruses are resistant to antibiotics.

Answer 50

C

Question 51

What prevents antibiotics from being effective against viruses?

Answer 51

Viruses have no metabolism

Question 52

Which statement is true for the antibiotic penicillin? A. Watson and Crick developed the usage of penicillin. B. Penicillin blocks processes unique to eukaryotic cells. C. Viruses lack metabolism and penicillin has no effect on them. D. Florey and Chain sequenced the genome of Penicillium notatum.

Answer 52

C

Question 53

What is a function of type I alveolar pneumocyte?

Answer 53

Carry out gas exchange

Question 54

What is the function of type II pneumocyte?

Answer 54

Produce surfactant

Question 55

Which process results in the exchange of gases across the membrane of pneumocytes?

Answer 55

Simple diffusion

Question 56

What muscle actions cause air to be expelled from the lungs?

Answer 56

Internal intercostal muscles contract and abdominal wall muscles contract

Question 57

Which muscle action is associated with an increase in the volume of the thoracic cavity when breathing in?

Answer 57

The diaphragm contracts

Question 58

What occurs during the establishment of a resting membrane potential of a neuron?

Answer 58

Sodium ions are pumped out while potassium ions are pumped into the neuron.

Question 59

If schizophrenia is caused by an overabundance of the neurotransmitters dopamine and serotonin in the synapses of some areas of the brain, which drug action could work in treating the symptoms?

Answer 59

Increased re-uptake of dopamine and serotonin by presynaptic neurons

Question 60

Which statement applies to an axon at rest?

Answer 60

The external surface of the plasma membrane is positive relative to the internal surface.

Question 61

What is saltatory conduction?

Answer 61

The propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials.

Question 62

Neurons transmit electrical impulses. Which statement describes part of this process?

Answer 62

Ion channels let Na+ diffuse into the cell to depolarize the membrane.

Question 63

What is the effect of atropine binding in synapses?

Answer 63

Prevents binding of acetylcholine at the postsynaptic membrane

Question 64

What is the fate of acetylcholine immediately after binding to the receptor?

Answer 64

It is broken down in the synaptic cleft.

Question 65

What is the change in membrane potential from resting potential to complete depolarization?

Answer 65

110 mV

Question 66

What happens when an action potential reaches motor end plates?

Answer 66

Neurotransmitter is released.

Question 67

What is the mechanism of sodium-potassium pumps in neurons that generates a resting potential by active transport?

Answer 67

Na+ from cytoplasm binds to the pump and stimulates its phosphorylation by ATP.

Question 68

What is a feature of neurons?

Answer 68

The cell body of a motor neuron is in the CNS.

Question 69

What happens first when a neurotransmitter binds to a postsynaptic neuron?

Answer 69

Ions diffuse

Question 70

Immediately after an action potential, which event causes the neuron membrane to repolarize?

Answer 70

Voltage-gated potassium channels open.

Question 71

What initiates an action potential along a neuron?

Answer 71

Neurotransmitters cause depolarization of membrane.

Question 72

Which response takes place when blood glucose levels are low?

Answer 72

Glucagon is released from the α cells of the pancreatic islets.

Question 73

During the menstrual cycle, what occurs in response to a fall in the progesterone level?

Answer 73

Menstruation

Question 74

For what reason are daily FSH injections given during IVF treatment?

Answer 74

To induce the ovary to produce more eggs than normal

Question 75

What is used in a pregnancy test kit?

Answer 75

Monoclonal antibodies produced by hybridoma cells against HCG

Question 76

What causes gonads to develop as testes in humans?

Answer 76

Activation and transcription of a gene on the Y chromosome

Question 77

The hormones insulin, glucagon, thyroxin and leptin can all affect energy storage in the body. Which hormone increases the rate of energy release and use?

Answer 77

Thyroxin

Question 78

What releases leptin?

Answer 78

Adipose tissue

Question 79

What is an example o negative feedback in the menstruation cycle?

Answer 79

High levels of estrogen inhibit FSH secretion

Question 80

What is the role of hormone leptin?

Answer 80

To inhibit appetite

Question 81

What do beta cells of pancreas release?

Answer 81

Insulin

Question 82

What do alpha cell of the pancreas release?

Answer 82

Glucagon

Question 83

Which hormone shows the greatest fall in blood concentration just before menstruation?

Answer 83

Progesterone

Question 84

What happens when human body temperature rises during exercise?

Answer 84

The water from sweat evaporates to cool the body

Question 85

What characterizes type I diabetes?

Answer 85

The beta cells of the pancreas are destroyed, usually during childhood

Question 86

How does the hypothalamus respond to a very high body temperatre?

Answer 86

Causes dilation of skin arterioles

Question 87

What is a characteristic of type II diabetes?

Answer 87

Liver cells are less sensitive to insulin

Question 88

What is the function of LH (luteinizing hormone) in the menstrual cycle?

Answer 88

Stimulation of ovulation

Question 89

Why does shivering occur?

Answer 89

Shivering generates heat and raises body temperature

Question 90

Where is follicle stimulating hormone (FSH) produced in females and what is its function?

Answer 90

Produced by the pituitary gland and stimulates the growth of follicles

Question 91

What will be happening in a person after eight hours of sleep?

Answer 91

Alpha cells in the pancreas will be producing glucagon

Question 92

Glucose turns into...

Answer 92

Glycogen

Question 93

Glucagon and insulin are...

Answer 93

Hormones

Question 94

Which of the following are controlled by homeostasis? I. Blood pH II. Water balance III. Blood glucose concentration

Answer 94

I, II, III

Question 95

What are the roles of testosterone in males?

Answer 95

Pre-natal development of genitalia and development of secondary sexual characteristics

Question 96

What is the consequence of insufficient secretion of FSH in women?

Answer 96

Mature eggs (oocytes) are not produced.

Question 97

The concentration of which hormone peaks sharply triggering ovulation?

Answer 97

LH (luteinizing hormone)