The Ultimate Year 12 Biology Test
Why did I make this? I don't know. The only thing I know is you should take the test. Good luck and have fun.
- 1.
List all the components of a negative feedback system (in the order of process)
- 2.
Explain why hyperventilation can result in alkalosis (insufficient CO2)
- 3.
Explain the significance of reversible binding reactions of haemoglobin.
- 4.
Describe blood glucose regulation with reference to the role of hormones.
- 5.
Explain how the following parts of the nerve increases transmission of an impulse: Myelin sheath, Nodes of Ranvier, Dendrites
- 6.
Explain the role of ion pumps during nerve impulses.
- 7.
What is homeostasis?
- A.
The body’s ability to regulate its internal environment despite external changes.
- B.
The functions required for organisms to sustain life.
- C.
The body's ability to control movement through a body system.
- D.
The process of which the body absorbs nutrients.
Correct Answer
A. The body’s ability to regulate its internal environment despite external changes.Explanation
Homeostasis refers to the body's ability to maintain a stable internal environment despite external fluctuations. This includes regulating temperature, pH levels, and other physiological variables within a narrow range. It is crucial for the proper functioning of cells, tissues, and organs. The body achieves homeostasis through various mechanisms, such as feedback loops and hormonal control, which help to restore balance and ensure optimal conditions for the body's cells to function properly.Rate this question:
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- 8.
Which one of these are true?
- A.
Negative feedback takes in stimulus to reinforce a process until it reaches an end point. Positive feedback draws on stimulus to alter the process until it falls back into normal limits.
- B.
Positive feedback takes in stimulus to reinforce a process until it reaches an end point. Negative feedback draws on stimulus to alter the process until it falls back into normal limits.
Correct Answer
B. Positive feedback takes in stimulus to reinforce a process until it reaches an end point. Negative feedback draws on stimulus to alter the process until it falls back into normal limits.Explanation
Positive feedback takes in stimulus to reinforce a process until it reaches an end point. This means that when a certain stimulus is received, it leads to an amplification or increase in the process, pushing it towards completion or an endpoint. On the other hand, negative feedback draws on stimulus to alter the process until it falls back into normal limits. This means that when a certain stimulus is received, it leads to a response that counteracts the stimulus, bringing the process back to its normal range or limits.Rate this question:
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- 9.
Which one of these are an accurate metaphor for a negative feedback system?
- A.
The effect of fruit ripening on adjacent fruit
- B.
Driving a car while observing speed limit
- C.
Your dad patting your back and saying "well done son"
- D.
Correlation of population growth vs births per year
Correct Answer
B. Driving a car while observing speed limitExplanation
When you drive, you must step on the gas pedal to accelerate your car to near the appropriate speed limit. If your speed exceeds it however, you would let go of the gas pedal to allow the car to slow down. Once you're beginning to be too slow, you start it again. This is an example of negative feedback.Rate this question:
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- 10.
What is the role of the hypothalamus and pituitary gland?
- A.
The pituitary gland detects changes in the body and sends a response to the hypothalamus
- B.
The hypothalamus is in charge of the endocrine system and the pituitary gland is in charge of the nervous system
- C.
The pituitary gland is in charge of the endocrine system and the hypothalamus is in charge of the nervous system
- D.
The hypothalamus detects changes in the body and sends a response to the pituitary gland
Correct Answer
D. The hypothalamus detects changes in the body and sends a response to the pituitary glandExplanation
In the endocrine system, the hypothalamus detects changes all around the body. This means that it is very important in maintaining various functions around the body. Once it detects something is off, it sends a message to the pituitary gland. The pituitary gland sends out many different types of hormones that are needed in body regulation.Rate this question:
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- 11.
Which of these are the characteristics of the nervous system and NOT the endocrine system?
- A.
Fast-acting
- B.
Slow-acting
- C.
Uses electro-chemical signals
- D.
Uses chemical signals
- E.
Involves the use of glands
- F.
Travels through nerves
- G.
Travels through the blood stream
- H.
Regulates smooth muscle movement
- I.
Has rapid effects
- J.
Has long-lasting effects
Correct Answer(s)
A. Fast-acting
C. Uses electro-chemical signals
F. Travels through nerves
H. Regulates smooth muscle movement
I. Has rapid effectsExplanation
The nervous system sends electric messages through nerves that run along the body. They're rapid, just like electricity cables in the city. As soon as you turn the TV on, it instantly turns on. The endocrine system is more like city piping, where it's fast, but not as fast. The endocrine system's hormones travel through the blood stream.Rate this question:
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- 12.
List the components of the respiratory system
- A.
Nostrils
- B.
Lungs
- C.
Pharynx
- D.
Trachea
- E.
Duodenum
- F.
Larynx
- G.
Oesophagus
- H.
Alveoli
- I.
Stomach
- J.
Tongue
- K.
Diaphragm
- L.
Bronchus
Correct Answer(s)
A. Nostrils
B. Lungs
D. Trachea
F. Larynx
H. Alveoli
K. Diaphragm
L. BronchusExplanation
The upper respiratory tract consists of the nose (and also the oral cavity, cause you can breathe in through your mouth too), larynx (aka voice box) and then the trachea. The lower respiratory tract consists of the lungs, which are joined by bronchus, that split smaller and smaller till it reaches the alveoli. The diaphragm sits below the lungs.Rate this question:
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- 13.
Which of these statements are correct?
- A.
The diaphragm contracts during inhalation to increase lung volume
- B.
The diaphragm relaxes during inhalation to decrease lung volume
- C.
The diaphragm contracts during inhalation to decrease lung volume
- D.
The diaphragm relaxes during inhalation to increase lung volume
- E.
The diaphragm doesn't move during inhalation
Correct Answer
A. The diaphragm contracts during inhalation to increase lung volumeExplanation
When you breathe in, the diaphragm contracts and moves down. This expands the volume of the lungs.Rate this question:
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- 14.
What allows inhalation/inspiration?
- A.
Air entering the lungs, which has a lower volume than outside
- B.
Air entering the lungs, which has a higher volume than outside
- C.
The nose sucking in air particles
- D.
The lungs pumping in air
Correct Answer
B. Air entering the lungs, which has a higher volume than outsideExplanation
Despite what it feels like, breathing isn't a matter of sucking air in or blowing it out. The air flow is manipulated through pressure differences. Increasing the volume of the lungs makes them have lower air pressure. Because air will travel from places with high pressure to places with low pressure, the air will invite itself into your lungs. The opposite happens when you exhale, where you squeeze your lungs smaller so the air leaves.Rate this question:
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- 15.
How is oxygen and carbon dioxide transported?
- A.
Passively diffused across all cells
- B.
Through air pipes around the body
- C.
Dissolved into lymphatic system
- D.
Dissolved into the blood stream
Correct Answer
D. Dissolved into the blood streamExplanation
More specifically, the gases are carried by red blood cells which are DISSOLVED into the blood.Rate this question:
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- 16.
What is blood pH determined by?
- A.
Whatever the pH tester says, I guess
- B.
Presence of oxygen
- C.
Presence of carbon dioxide
- D.
Presence of hydrochloric acid
Correct Answer
C. Presence of carbon dioxideExplanation
Carbon dioxide reacts with water to make carbonic acid. This stuff is of course in the blood stream and therefore makes blood acidic.Rate this question:
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- 17.
Check all the actions that the blood pH regulation loop performs in the case of excessive CO2 (acidosis)
- A.
Vasodilation
- B.
Increased respiration
- C.
Vasoconstriction
- D.
Decreased respiration
- E.
Decreased heart rate
- F.
Increased heart rate
Correct Answer(s)
A. Vasodilation
B. Increased respiration
F. Increased heart rateExplanation
All the following actions enable the body to increase the rate of gas exchange, which will remove carbon dioxide from the body faster.Rate this question:
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- 18.
What is the role of the heart and lungs in gas regulation?
- A.
The heart provide oxygenated blood and the lungs pump it around the body
- B.
The lungs provide oxygenated blood and the heart pumps it around the body
- C.
The heart pumps in oxygen and the lungs pump out carbon dioxide
- D.
The heart pumps in carbon dioxide and the lungs pump out oxygen
Correct Answer
B. The lungs provide oxygenated blood and the heart pumps it around the bodyExplanation
Honestly if you didn't get this one, I'd like to ask how you even passed the last two terms of year 12 biology.Rate this question:
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- 19.
What is the correlation between oxygen saturation in RBC's and oxygen level in blood?
- A.
Higher oxygen levels in the blood increase PO2, causing oxygen to bind with haemoglobin.
- B.
Lower oxygen levels in the blood decrease PO2, causing oxygen to bind with haemoglobin.
- C.
Higher oxygen levels in the blood increase PO2, causing oxygen to bind less with haemoglobin.
- D.
Lower oxygen levels in the blood decrease PO2, causing oxygen to bind more with haemoglobin.
Correct Answer
A. Higher oxygen levels in the blood increase PO2, causing oxygen to bind with haemoglobin.Explanation
Just like being cramped in the hall, once the door opens, people would be more inclined to rush out into the open area.Rate this question:
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- 20.
Which of the following is FALSE?
- A.
Both veins and arteries have endothelial cells.
- B.
Arteries have elastin on the outside coating while veins do not.
- C.
Both veins and arteries can stretch.
- D.
Veins possess valves while arteries do not.
- E.
Capillaries are one-cell thick.
Correct Answer
B. Arteries have elastin on the outside coating while veins do not.Explanation
Both arteries and veins have elastin, but this is of course thicker in arteries.Rate this question:
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- 21.
List the organs that are part of the excretory system
- A.
Lungs
- B.
Bladder
- C.
Stomach
- D.
Penis
- E.
Kidney
- F.
Large intestine
- G.
Liver
- H.
Anus
- I.
Urethra
Correct Answer(s)
B. Bladder
E. Kidney
F. Large intestine
H. Anus
I. UrethraExplanation
The excretory system includes the lower part of the digestive tract (intestines and downwards), and also the urinary tract, which includes the kidneys, bladder and erethra. Although urine can come out the penis, it technically isn't included into the body system.Rate this question:
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- 22.
What is the function of the ascending and descending limbs in the loop of Henle?
- A.
The descending limb filters out water while the ascending limb filters out salts
- B.
The descending limb filters out salts while the ascending limb filters out water
- C.
Both the descending limb and ascending limb can filter out both
- D.
What limbs?
Correct Answer
A. The descending limb filters out water while the ascending limb filters out saltsExplanation
Because of a concentration gradient, water and salts move passively. In the descending limb, the very salty external environment causes water to be drawn out. As the loop moves up and back into the less salty area (cortex), salt leaves.Rate this question:
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- 23.
How does ADH (Anti-diuretic hormone) work?
- A.
Restricts blood flow into the kidneys
- B.
Decreases the re-absorption of salt
- C.
Increases the re-absorption of water
- D.
Makes urination less frequent
Correct Answer
C. Increases the re-absorption of waterExplanation
ADH increases the permeability of the tubules in the nephron, so water is more easily absorbed back into the blood stream. This creates more concentrated urine. Yes, that also means you pee less, but low amount of urination can be due to other reasons too.Rate this question:
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- 24.
Check the following factors that may trigger ADH to be released
- A.
Sweating a lot on a hot day
- B.
A low blood pressure
- C.
A high blood pressure
- D.
Drinking a large bottle of water in one go
- E.
Not drinking water in a while
Correct Answer(s)
A. Sweating a lot on a hot day
B. A low blood pressure
E. Not drinking water in a whileExplanation
ADH causes the body to retain water, which may happen if the body feels their water level is low. Perspiration causes the body to lose a lot of water. A low blood pressure can result due to low water level in the blood plasma, and not drinking water regularly will cause the body to be unable to replenish fluid levels. Drink up!Rate this question:
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- 25.
Which of the following present the reflex arc in the right order?
- A.
Stimulus, sensory neuron, the brain, motor neuron, response
- B.
Stimulus, receptor, sensory neuron, the brain, motor neuron, effector, response
- C.
Stimulus, receptor, sensory neuron, relay neuron, motor neuron, effector, response
- D.
Stimulus, receptor, effector, response
Correct Answer
B. Stimulus, receptor, sensory neuron, the brain, motor neuron, effector, responseExplanation
A reflex arc happens involuntarily, without conscious thought. During the arc, the message is relayed to the receptor and passes through the sensory neuron, then the relay neuron, then directly to the motor neuron and effector. Of course, the brain will still get a message of what's going on, but it won't be immediately and won't affect the reflex arc because it's already done.Rate this question:
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- 26.
Which of the following are FALSE?
- A.
The CNS consists of the brain and spinal chord while the PNS consists of the rest of the body
- B.
The CNS is in charge of involuntary responses while the PNS controls voluntary responses
- C.
The CNS receives information and coordinates activity, which the PNS can relay to the rest of the body
- D.
The CNS is more protected than the PNS
Correct Answer
B. The CNS is in charge of involuntary responses while the PNS controls voluntary responsesExplanation
The CNS and PNS aren't separated by voluntary and involuntary responses because they both do that. The main difference is just the components that make up the systems.Rate this question:
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- 27.
What differentiates the somatic nervous system (SoNS) and the autonomic nervous system (ANS)?
- A.
The SoNS is part of the PNS while the ANS is part of the CNS
- B.
The SoNS controls involuntary functions while the ANS is for voluntary functions
- C.
The SoNS can be controlled voluntarily while the ANS is below the level of consciousness
- D.
An extra letter in the acronym
Correct Answer
C. The SoNS can be controlled voluntarily while the ANS is below the level of consciousnessExplanation
Both the SoNS and the ANS are under the peripheral nervous system. The SoNS is associated with voluntary functions (like moving your hand) while the ANS is associated with visceral functions (a boner).Rate this question:
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- 28.
Which of the following correctly complete the action potential graph?
- A.
1. Hyperpolarisation 2. Repolarisation 3. Depolarisation
- B.
1. Hyperpolarisation 2. Depolarisation 3. Repolarisation
- C.
1. Repolarisation 2. Depolarisation 3. Hyperpolarisation
- D.
1. Depolarisation 2. Repolarisation 3. Hyperpolarisation
Correct Answer
D. 1. Depolarisation 2. Repolarisation 3. HyperpolarisationExplanation
Once a neuron receives a stimulus, it undergoes depolarisation, which causes the cell to lose its negative charge. After a certain point, the cell repolarises and falls back to a negative charge again. However, it typically overshoots, resulting in a hyperpolarisation. This is a temporary period of time where the nerve isn't ready to receive another signal. The charge then returns back to its normal level.Rate this question:
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- 29.
What are the correct charges for each stage?
- A.
+70V for resting, +55V for threshold, -40V for depolarisation
- B.
-40V for resting, -55V for threshold, +70V for depolarisation
- C.
-60V for resting, -50V for threshold, +35V for depolarisation
- D.
-70V for resting, -55V for threshold, +40V for depolarisation
Correct Answer
D. -70V for resting, -55V for threshold, +40V for depolarisation -
- 30.
How are action potentials transmitted between neurons across chemical synapses?
- A.
Post-synaptic terminal -> Receptor Region -> Synaptic Cleft -> Synaptic Vesicle -> Pre-synaptic terminal
- B.
Pre-synaptic terminal -> Receptor Region -> Synaptic Cleft -> Synaptic Vesicle -> Post-synaptic terminal
- C.
Post-synaptic terminal -> Synaptic Vesicle -> Synaptic Cleft -> Receptor Region -> Pre-synaptic terminal
- D.
Pre-synaptic terminal -> Synaptic Vesicle -> Synaptic Cleft -> Receptor Region -> Post-synaptic terminal
Correct Answer
D. Pre-synaptic terminal -> Synaptic Vesicle -> Synaptic Cleft -> Receptor Region -> Post-synaptic terminalExplanation
The presynaptic terminal is the end of the first neuron. The impulse travels down the axon and into the synaptic vesicle, where neurotransmitters transmit the message in chemical form. Passing a gap called a synaptic cleft, the chemical message reaches the receptor region, which converts the message back into electric form. This then moves along the axon and reaches the post-synaptic terminal and it starts again.Rate this question:
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- 31.
Why are neurotransmitters deactivated soon after release?
- A.
So the signal can be controlled to stop after it is transmitted
- B.
So the signal can be transmitted faster
- C.
Neurotransmitters don't get deactivated
- D.
So that the neurotransmitters can reach more cells at once
Correct Answer
A. So the signal can be controlled to stop after it is transmittedExplanation
Neurotransmitters are deactivated soon after release to ensure that the signal can be controlled and stopped after it is transmitted. This allows for precise regulation of neuronal communication and prevents continuous stimulation or overexcitation of the receiving cells. By deactivating neurotransmitters, the nervous system can maintain proper signaling and prevent excessive or prolonged activation, which could lead to detrimental effects on the body.Rate this question:
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- 32.
The alveoli are sacs where gas exchange occurs. Oxygen and carbon dioxide ________ between the ducts and capillaries.
- A.
Is pumped
- B.
Diffuses
- C.
Appears
- D.
Is generated
Correct Answer
B. DiffusesExplanation
Oxygen and carbon dioxide is exchanged through diffusion between the one-cell thick ducts and capillaries.Rate this question:
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- 33.
Oxygen is carried in the blood stream by a protein called haemoglobin. It can carry up to _______ oxygen molecules.
- A.
5
- B.
1
- C.
2
- D.
4
Correct Answer
D. 4Explanation
Haemoglobin has a quaternary structure. It can carry up to 4 oxygen molecules at once.Rate this question:
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- 34.
A _______ is a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.
- A.
Channel
- B.
Synapse
- C.
Neuron
- D.
Nerve
Correct Answer
B. SynapseExplanation
self-explanatoryRate this question:
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- 35.
When an impulse arrives to the axon terminals, they depolarise. This causes the Ca2+ gates to open. The influx of calcium ions trigger vesicles to ________ neurotransmitters.
- A.
Duplicate
- B.
Withdraw
- C.
Release
- D.
Absorb
Correct Answer
C. ReleaseExplanation
Ca2+ channels play a vital role in nerve relays because the influx of calcium ions allow neurotransmitters to do their job.Rate this question:
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