Download chapter 3 excretion

CHAPTER 3 EXCRETION
SUBJECTIVE QUESTIONS
3.1 Human Excretion
1
Complete the table below by stating the method of excretion
and excretory materials for the following excretory organ.
Excretory organ
(a) Skin
(b) Lungs
(c) Kidneys
2
Method of excretion
Excretory materials
Fill in the blanks with the words given.
skin
toxic
water
excretion
(a) The process of removing waste products, produced
during chemical processes in the cells, is
called ___________________.
(b) If wastes are not removed, _____________ substances
build up and these can damage organs in the body.
(c) The excretory products of humans
are _____________ , carbon dioxide, urea and mineral
salts.
(d) The excretory organs of humans are lungs, _________
and the kidneys.
3.2 The Urinary System in Humans
3
Tick  the statements below that are true.
(a) The kidneys are located at the back of the body and
form the main organs of the urinary system.
(b) The function of the kidney is to remove water and
carbon dioxide.
(c)
4
The kidneys are bean-shaped and roughly the size of a
fist.
Name the parts of the human urinary system based on the
following functions.
Parts of urinary
system in human
(a)
Tube that carries urine from the
kidney to the bladder
Excretory organ that removes
wastes like urea,water and
mineral salts from the blood into
the urine
Tube that carries urine from the
bladder for removal
Temporary storage for the urine
before removal
(b)
(c)
(d)
5
Function
Label the human kidney using the words given.
Cortex
Artery
Ureter
Medulla
Vein
Pelvis of kidney
(a)
(f)
(b)
(c)
(e)
(d)
3.3 Excretion in Plants
6
Underline the correct word in the brackets so that each
sentence becomes a true statement.
(a) Plants excrete water, [urea, mineral salts], oxygen,
carbon dioxide and other nitrogenous wastes.
(b) Plants excrete their waste products by simple diffusion
through the cell [wall, membrane] and through the
stomata.
OBJECTIVE QUESTIONS
3.1 Human Excretion
1
Which of the following excretory products are excreted
through the lungs?
A
Water and urea
B
Water and mineral salts
C
Carbon dioxide and salts
D
Carbon dioxide and water
2
All the following are excretory organs except
A
skin
C lungs
B
heart
D kidneys
3.2 The Urinary System in Humans
3
Which of the following is not a function of the kidneys?
A
It removes urea from the body
B
It controls the pH of the blood
C
It removes excess sugar in the blood
D
It regulates the amount of water and mineral salts in the
body
4
Diagram 1 shows the cross section of the human kidney.
P
Q
S
R
Diagram 1
Which part marked P, Q, R and S carries urine from the
kidney to the urinary bladder?
A
P
C R
B
Q
D S
5
Which of the following are not true?
A
B
C
D
Excretory product
Water
Mineral salts
Urea
Carbon dioxide
Excretory organ
Kidneys
Skin
Lungs
Lungs
3.3 Excretion in Plants
6
Which of the following excretory products from plants can be
used to relieve pain?
A
Latex
C Resin
B
Tannin
D Caffeine
7
Which of the following plants produce latex?
A
Soya
C Rubber tree
B
Coconut tree
D Sunflower plant
REVISION
1
Which of these are excretory organs?
I
II
III
A
B
2
I an II only
I and III only
C II and III only
D I, II and III
Which of the following excretory product does not match?
A
B
C
D
Excretory organs
Kidney
Lungs
Skin
Skin
Excretory product
Mineral salts
Water
Urea
Carbon dioxide
3
Diagram 1 shows the human urinary system.
Vena cava
Right kidney
Aorta
Left kidney
J
K
L
Diagram 1
(a) Name the parts labelled J, K and L.
J : _______________________________
K : _______________________________
L : _______________________________
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(b)
State the function of the kidneys.
__________________________________________
(c)
Describe what happens to the body when both kidneys
fail.
__________________________________________
__________________________________________
(d)
State how kidney failure can be treated.
__________________________________________
__________________________________________
The following information describes the excretion of plants.
(a)
Some of the excretory products in plants
are useful to humans while others are
poisonous.
State three excretory products of plants that are harmful
to humans.
___________________________________________
(b)
___________________________________________
Name the parts of plants that will eliminate the
following excretory products.
(i) Latex
_______________________________________
(ii) Quinine
________________________________________