Transcript Document

INTERACTIVE
MULTIPLE-CHOICE
QUESTIONS
Human Physiology
The answers are provided.
Explanations of why the alternatives
are unsatisfactory are also offered
© D.G. Mackean
These multiple choice questions are similar to the ones set
by the GCSE and IGCSE Examination Boards except that,
in some cases, there may be more than one acceptable
answer.
For this reason, even if you select a correct answer at your
first attempt, it is worth looking at all the alternatives
(a) to see if there is a better answer and
(b) to see why some of the alternatives are
unacceptable
Question 1
Question 1
Iron is an important component of a balanced
diet because it is needed mainly by …
(a) the blood
(b) the bones
(c) the brain
(d) the nerves
Question 2
Yes
Iron is an important component of haemoglobin,
the red pigment which combines with oxygen in
the red blood cells
No
Iron is not specifically needed by the bones
No
Iron is not specifically needed by the nerves
No
Iron is not specifically needed by the brain
Question 2
Shortage of vitamin D in the diet of children can
lead to …
(a) poor night vision
(b) anaemia
(c) deformed bones
(d) bleeding gums
Question 3
No
It is shortage of vitamin A (retinol) which is a cause
of poor night vision, as well as reduced resistance
to disease
No
A shortage of iron can be one cause of anaemia
Yes
A shortage of vitamin D (calciferol) causes defective
incorporation of calcium into the bones, which therefore
remain soft and are easily deformed. This condition is
known as ‘rickets’
No
A shortage of vitamin C (calciferol) can be one cause
of bleeding gums
Question 3
The final digestion products of proteins are …
(a) sugars
(b) glycerols
(c) fatty acids
(d) amino acids
Question 4
No
Sugars (e.g. glucose and fructose) are the final digestion
products of carbohydrates, such as starch
No
Glycerol is one of the products of fat digestion
No
Fatty acids are one of the products of digestion of fats
Yes
The final digestion products of proteins are amino acids
Question 4
In the small intestine, the villi …
(a) speed up digestion
(b) propel food through the intestine
(c) increase the absorptive surface
(d) secrete digestive enzymes
Question 5
No
The villi speed up absorption
No
Food is propelled through the alimentary canal by a
muscular process called peristalsis
Yes
The numerous, finger-like processes called villi, greatly
increase the absorptive surface of the small intestine
Section of small
intestine opened
to show villi
No
The villi contain enzymes but they do not secrete them
into the intestine
Question 5
When the ventricles contract, blood is forced into …
(a) the aorta
(b) the vena cava
(c) the pulmonary artery and the aorta
(d) the pulmonary artery
Question 6
Yes but …
Contraction of the left ventricle forces blood into the aorta,
but the right ventricle is contracting at the same time
No
The vena cava brings blood to the right ventricle
Yes
Contraction of the left ventricle forces blood into the
aorta. Contraction of the right ventricle forces blood
into the pulmonary artery
Yes but …
Contraction of the right ventricle forces blood into the
pulmonary artery but remember that the left ventricle is
also contracting.
Question 6
In the lungs, gaseous exchange takes place in …
(a) the alveoli
(b) the bronchioles
(c) the bronchi
(d) the trachea
Question 7
Yes
The alveoli are tiny air pockets at the ends
of the bronchioles. Oxygen from the air
diffuses into the blood capillaries in their
walls and carbon dioxide diffuses out
trachea
alveoli
bronchiole
bronchi
lung
No
The bronchioles are the fine tubes which carry air to the
alveoli but significant gaseous exchange does not take
place here
No
The bronchi are the wide tubes which branch repeatedly
to form the bronchioles. No significant gaseous
exchange takes place here.
No
The trachea is the wide tube leading from the
back of the mouth and dividing into bronchi. No
significant gaseous exchange takes place here
Question 7
Which of the following are excretory organs?
(a) The lungs
(b) The skin
(c) The kidneys
(d) The large intestine
Question 8
Yes
The lungs excrete carbon dioxide which is a waste
product of cellular respiration.
They also expel water vapour some of which could be a
waste product of respiration, but this is incidental to
their main function and an inevitable consequence of the
moist lining of the alveoli
No
Sweat, from the sweat glands in the skin, contains salt
(sodium chloride) but this is incidental to the main function
of sweat production (cooling the body). The sweat glands do
not produce sweat in response to an increase in sodium
chloride in the blood and are not, therefore, organs of
excretion.
In fact, loss of salt which results from prolonged sweating
can be harmful.
Yes
The kidneys excrete, urea, uric acid, excess salts and the
breakdown products of hormones or drugs. These
substances are all waste products of the body’s
metabolism.
The kidneys also excrete excess water, some of which has
been produced in the process of respiration.
No
The contents of the large intestine are largely made up of
undigested vegetable matter (fibre), bacteria and water.
These have not been incorporated into the body or
taken part in chemical changes in the body so they are
not excretory products.
The process of expelling faeces is egestion, not excretion
The break down products of bile pigments, which colour
the faeces, are excretory products but are excreted by the
liver
Question 8
follicle-stimulating
hormone
progesterone
oestrogen
Days
The graphs represent the relative
concentrations of 3 female
hormones in the blood over a 28
day period. In which period is
fertilisation (conception) most
likely to occur?
(a) Days 1 - 5
(b) Days 10 -12
(c) Days 13-16
(d) Days 20 - 24
Question 9
No
This is the period when menstruation is taking place
No
Although the concentration of oestrogen is high, there
is unlikely to be an ovum present in the oviduct at this
stage
Yes
Follicle-stimulating hormone is one of the hormones that
triggers the release of an ovum from the ovary (ovulation).
Assuming the ovum can survive for a day, and sperms can
survive for 2 days this is the fertile period when conception
is most likely
No
The ovum is unlikely to survive into this period. The
increase in progesterone causes the lining of the uterus
to thicken in preparation for the ovum, if it has been
fertilised
Question 9
Which of the following are the likely effects of release of
adrenaline from the adrenal gland into the bloodstream?
(a) The rate and depth of breathing increases
(b) The liver converts glucose in the blood to glycogen
(c) The skeletal muscles relax
(d) The heart rate increases
Question 10
Yes
Adrenaline is the ‘fight or flight’ hormone and prepares
the body for action. An increase in the rate and depth of
breathing gets more oxygen into the blood. This means
that more prolonged activity can occur.
No
Adrenaline causes the liver to convert its glycogen store to
glucose which is released into the bloodstream where it
becomes available for rapid muscular contraction.
No
Adrenaline causes the muscles to tense up in preparation
for ‘flight or fight’
Yes
An increased heart rate helps to supply extra oxygen
and glucose to the muscles for their heightened
activity during ‘flight or fight’
Question 10
Which of the following are reflex actions?
(a) You ‘jump’ in response to a sudden and
unexpected loud noise
(b) You automatically move the handlebars of your
bicycle to steer or to keep your balance
(c) You walk without thinking about it
(d) You blink when a particle of sand blows
into your eye
Question 11
Yes
You have no control over whether you ‘jump’ or not.
This is a reflex action
No
Although this happens without your having to think about it,
it is a ‘learned’ reaction and not a reflex. An acquired skill is
not a reflex
No
Although this happens without your having to think about it,
it is a ‘learned’ reaction and not a reflex. An acquired skill is
not a reflex
Yes
You have no control over whether you blink or not
Question 11
The drawing represents the
skeleton and muscles of the leg.
When the leg straightens to thrust
the body forwards, which of the
following is the correct sequence?
A
B
(a) A contracts, B relaxes,
C relaxes, D contracts
(b) B contracts, A relaxes,
D contracts, C relaxes
C
D
(c) A contracts, B relaxes,
C contracts, D relaxes
(d) A contracts, B contracts,
C relaxes, D relaxes
Question 12
No
If D contracts, it flexes the foot at the ankle. The foot
must be extended if it is to push the body forwards
No
If B contracts, it will flex (bend) the leg at the
knee. This will not help to push the body forward
If D contracts, it flexes the foot at the ankle. The foot
must be extended if it is to push the body forwards
Yes
A contracts and extends
(straightens) the leg at
the knee
C contracts and
extends (straightens)
the foot at the ankle
These two movements
make the leg push
against the ground
and thrust the body
upwards and forwards
B
relaxes
C contracts
A
contracts
D relaxes
B and D must be relaxed to allow
their antagonistic muscles to
contract
No
A and B are antagonistic muscles. If they both try
to contract there will be no movement. However,
the tension in both must be retained in order to
hold the body upright in a standing position
If C and D both relax, there will be nothing to
support the ankle and you will fall flat on your face
Question 12
Which of the following is the best definition of
‘homeostasis’ in mammals?
(a) Keeping the body temperature constant
(b) Maintaining a constant internal environment
(c) Getting rid of the waste products of metabolism
as fast as they accumulate
(d) Maintaining a constant body mass
No
Keeping the body temperature within limits is only one aspect
of homeostasis
Yes
This is the best definition (provided you know what it means)
The ‘internal environment’ refers mainly to the blood, lymph
and tissue fluid. Homeostasis involves all the processes which
keep the temperature and composition of these fluids within
narrow limits
The lungs control the levels of oxygen and carbon dioxide. The
kidneys eliminate excretory products and maintain the
concentration.
The skin helps to regulate the temperature
The liver controls the concentration of glucose
And the brain, nervous system and endocrine system
control them all
No
This is just one aspect of homeostasis. The kidneys get rid
of the waste products of metabolism as fast as they
accumulate and control the amount of water retained in the
body
No
Even in a mature animal, the body mass will fluctuate with
the seasons, the activity and the availability of food.
With an immature animal the body mass will increase
End of questions
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