Online Test — Excretion and Nervous System
50 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 50
The removal of harmful metabolic wastes from the body is called:
Nutrition
Excretion
Respiration
Digestion
Explanation: Excretion is the removal of harmful wastes produced by life processes.
Question 2 of 50
Plants release waste gases and excess water mainly through tiny pores called:
Villi
Stomata
Nephrons
Alveoli
Explanation: Stomata on the leaves allow gases and water vapour to leave.
Question 3 of 50
Which of these is a way plants remove stored wastes?
Sweating
Leaf fall and bark shedding
Urinating
Breathing through gills
Explanation: Shedding leaves and bark removes wastes stored in them.
Question 4 of 50
The milky fluid stored by some plants, used to make rubber, is:
Resin
Gum
Latex
Tannin
Explanation: Latex (e.g. from the rubber tree) is used to make rubber.
Question 5 of 50
Compared with animals, plants excrete in ways that are generally:
More complex
Simpler and slower
Faster and forced
Identical
Explanation: Plants use simpler, slower methods and have no special excretory organs.
Question 6 of 50
The main nitrogen-containing waste removed in human urine is:
Glucose
Urea
Oxygen
Protein
Explanation: Urea, from the breakdown of extra proteins, is the main waste.
Question 7 of 50
The bean-shaped organs that filter the blood are the:
Lungs
Kidneys
Liver lobes
Bladders
Explanation: The kidneys filter the blood and produce urine.
Question 8 of 50
Urine is carried from the kidneys to the bladder by the:
Urethra
Ureters
Trachea
Veins
Explanation: The ureters carry urine from the kidneys to the bladder.
Question 9 of 50
The organ that stores urine until it is released is the:
Kidney
Ureter
Urinary bladder
Urethra
Explanation: The urinary bladder stores urine until urination.
Question 10 of 50
The functional (filtering) unit of the kidney is the:
Alveolus
Nephron
Neuron
Villus
Explanation: The nephron is the kidney's functional unit; each kidney has about a million.
Question 11 of 50
Urine is formed in the nephron in how many main stages?
One
Two
Three
Five
Explanation: Urine forms in three stages: filtration, reabsorption, and secretion.
Question 12 of 50
During filtration, which of these stays behind in the blood?
Water
Glucose
Proteins
Salts
Explanation: Large proteins (and blood cells) are too big to be filtered out.
Question 13 of 50
The stage in which useful substances like glucose are taken back into the blood is:
Filtration
Reabsorption
Secretion
Excretion
Explanation: Reabsorption returns useful substances (e.g. glucose) to the blood.
Question 14 of 50
The main waste substance dissolved in urine is:
Glucose
Urea
Protein
Starch
Explanation: Urea is the main nitrogen waste present in urine.
Question 15 of 50
The presence of glucose in urine may indicate the disease:
Common cold
Diabetes
Malaria
Anaemia
Explanation: Glucose in urine can be a sign of diabetes (high blood glucose).
Question 16 of 50
The skin excretes wastes in the form of:
Urine
Sweat
Bile
Saliva
Explanation: The skin removes wastes as sweat through sweat glands.
Question 17 of 50
Sweat is mostly made of:
Salts
Water
Urea
Glucose
Explanation: Sweat is mostly water, with some salts and a little urea.
Question 18 of 50
The control of the body's temperature is called:
Excretion
Thermoregulation
Digestion
Respiration
Explanation: Thermoregulation is the control of body temperature.
Question 19 of 50
The evaporation of sweat helps the body by:
Adding heat
Removing heat (cooling)
Making urine
Storing water
Explanation: Evaporating sweat takes heat from the body, cooling it.
Question 20 of 50
When the body is too hot, the blood vessels near the skin:
Widen to lose heat
Narrow to keep heat
Disappear
Stop carrying blood
Explanation: When hot, skin blood vessels widen so heat is lost to the air.
Question 21 of 50
The basic structural and functional unit of the nervous system is the:
Nephron
Neuron
Alveolus
Villus
Explanation: The neuron (nerve cell) is the unit of the nervous system.
Question 22 of 50
The short branching parts of a neuron that receive impulses are the:
Axon
Dendrites
Myelin sheath
Synapse
Explanation: Dendrites receive impulses and carry them to the cell body.
Question 23 of 50
The long fibre that carries the impulse away from the cell body is the:
Dendrite
Axon
Cell body
Pore
Explanation: The axon carries the impulse away from the cell body.
Question 24 of 50
The fatty covering that insulates the axon and speeds up the impulse is the:
Myelin sheath
Nucleus
Cyton
Synapse
Explanation: The myelin sheath insulates the axon and speeds the impulse.
Question 25 of 50
The tiny gap between two neurons is called a:
Pore
Synapse
Valve
Lumen
Explanation: A synapse is the gap across which impulses pass between neurons.
Question 26 of 50
Neurons that carry impulses from sense organs to the brain or spinal cord are:
Motor neurons
Sensory neurons
Interneurons
Relay only
Explanation: Sensory (afferent) neurons carry impulses from receptors to the CNS.
Question 27 of 50
Motor neurons carry impulses from the central nervous system to the:
Sense organs
Effectors (muscles and glands)
Skin only
Eyes only
Explanation: Motor (efferent) neurons carry impulses to the muscles and glands.
Question 28 of 50
Neurons that connect sensory and motor neurons within the CNS are:
Sensory neurons
Motor neurons
Interneurons
Receptors
Explanation: Interneurons (relay neurons) link sensory to motor neurons.
Question 29 of 50
A muscle or gland that carries out a response is called a(n):
Receptor
Effector
Stimulus
Synapse
Explanation: An effector (muscle or gland) carries out the response.
Question 30 of 50
Sensory neurons are also known as ______ neurons.
Efferent
Afferent
Relay
Motor
Explanation: Sensory neurons carry impulses toward the CNS, so they are afferent.
Question 31 of 50
A nerve impulse is best described as a tiny:
Sound wave
Electrical signal
Drop of blood
Muscle
Explanation: A nerve impulse is an electrical signal travelling along a neuron.
Question 32 of 50
In a resting neuron, the inside is ______ compared with the outside.
Slightly positive
Slightly negative
Exactly equal
Has no charge
Explanation: At rest (resting potential), the inside is slightly negative.
Question 33 of 50
The brief flip in which the inside of the neuron becomes positive is the:
Resting potential
Action potential
Synapse
Reflex
Explanation: The action potential is the impulse, when the inside briefly becomes positive.
Question 34 of 50
The impulse is passed across the synapse by:
Electricity jumping the gap
Chemical neurotransmitters
Blood
Bones
Explanation: Neurotransmitters cross the synaptic gap to the next neuron.
Question 35 of 50
After an action potential passes, the neuron:
Dies
Returns to its resting state
Stays positive forever
Splits in two
Explanation: The neuron quickly returns to resting potential, ready to fire again.
Question 36 of 50
The two main divisions of the nervous system are the CNS and the:
RBC
PNS
DNA
ATP
Explanation: The nervous system has the central (CNS) and peripheral (PNS) divisions.
Question 37 of 50
The central nervous system is made up of the brain and the:
Heart
Spinal cord
Lungs
Kidneys
Explanation: The CNS consists of the brain and the spinal cord.
Question 38 of 50
The network of nerves connecting the CNS to the whole body is the:
Peripheral nervous system
Autonomic only
Skeleton
Circulatory system
Explanation: The PNS is the network of nerves linking the CNS to the body.
Question 39 of 50
The brain is protected inside the:
Backbone
Skull
Ribcage
Pelvis
Explanation: The brain is enclosed and protected by the skull.
Question 40 of 50
Automatic activities such as heartbeat and digestion are controlled by the:
Autonomic nervous system
Bones
Skin
Eyes
Explanation: The autonomic nervous system controls involuntary, automatic activities.
Question 41 of 50
The largest part of the brain, responsible for thinking and memory, is the:
Cerebellum
Cerebrum
Medulla oblongata
Spinal cord
Explanation: The cerebrum is the largest part and the centre of thought and memory.
Question 42 of 50
Which part of the brain controls balance, posture, and coordination of movement?
Cerebrum
Cerebellum
Medulla oblongata
Skull
Explanation: The cerebellum maintains balance and coordinates movements.
Question 43 of 50
Involuntary actions such as heartbeat and breathing are controlled by the:
Cerebrum
Cerebellum
Medulla oblongata
Dendrites
Explanation: The medulla oblongata controls vital involuntary actions.
Question 44 of 50
Voluntary actions, such as writing, are controlled mainly by the:
Cerebrum
Cerebellum
Medulla oblongata
Spinal cord
Explanation: The cerebrum controls voluntary (deliberate) actions.
Question 45 of 50
The brain is protected and cushioned inside the:
Backbone
Skull
Ribcage
Pelvis
Explanation: The brain is housed and protected within the skull.
Question 46 of 50
A sudden, automatic, quick response to a stimulus is called a:
Voluntary action
Reflex action
Habit
Thought
Explanation: A reflex action is a sudden, automatic, quick response to a stimulus.
Question 47 of 50
The pathway followed by a reflex action is called the:
Nerve net
Reflex arc
Synapse
Axon
Explanation: The reflex arc is the pathway of a reflex action.
Question 48 of 50
Reflex actions are controlled mainly by the:
Cerebrum
Spinal cord
Cerebellum
Skin
Explanation: Reflexes are controlled mainly by the spinal cord, making them fast.
Question 49 of 50
Which of these is an example of a reflex action?
Writing a letter
Knee-jerk when tapped
Singing a song
Reading aloud
Explanation: The knee-jerk is a classic reflex; the others are voluntary actions.
Question 50 of 50
Reflex actions are fast because the impulse:
Travels to the brain and back
Does not need to reach the brain first
Stops at the skin
Moves very slowly
Explanation: The impulse goes only to the spinal cord, not the brain, so it is fast.