Confidential Information - This is for official consumption
Life Sciences/ Excretion Grade 11
Vhembe East/ August 2026
Page 1 of 7
Question Paper
VHEMBE EAST DISTRICT
NATIONAL
SENIOR CERTIFICATE
GRADE 11
LIFE SCIENCES INFORMAL TEST
EXCRETION
QUESTION PAPER
27 AUGUST 2026
MARKS: 50
TIME: 1 hour
Copyright reserved
Please, turn over
Confidential Information - This is for official consumption
Life Sciences/ Excretion Grade 11
Vhembe East/ August 2026
Page 2 of 7
Question Paper
This question paper consists of 06 pages including the cover page.
INSTRUCTIONS AND INFORMATION
Read the following instructions carefully before answering the questions.
1.
Answer ALL the questions.
2.
Write ALL the answers in your ANSWER BOOK.
3.
Number the answers correctly according to the numbering system used in this
question paper.
4.
Present your answers according to the instructions of each question.
5.
ALL drawings should be done in pencil and labelled in blue or black ink.
6.
Draw diagrams or flow charts only when asked to do so.
7.
The diagrams in this question paper are NOT necessarily drawn to scale.
8.
Do NOT use graph paper.
9.
You may use a non-programmable calculator, protractor and a compass.
10.
Write neatly and legibly.
Copyright reserved
Please, turn over
Confidential Information - This is for official consumption
Life Sciences/ Excretion Grade 11
Page 3 of 7
Vhembe East/ August 2026
Question Paper
SECTION A
QUESTION 1
1.1.
Various options are provided as possible answers to the following questions.
Choose the correct answer and write only the letter (A to D) next to the question
number (1.1.1. to 1.1.4.) in the ANSWER SHEET. For example, 1.1.5. A.
1.1.1 Which one of the following is not the function of kidney in urinary system
A. Osmoregulation
B. Digestion
C. Excretion
D. Regulation of pH of body fluids
1.1.2 A hormone which is secreted by the cortex of the adrenal gland, which regulates
the concentration of sodium ions and potassium ions in the blood is:
A. Glucagon
B. ADH
C. Aldosterone
D. Insulin
1.1.3 The functional unit of a kidney is
A. Nephron
B. Mlpighian body
C. Urine
D. Glomerulus
1.1.4 The process of keeping the internal body environment constant is ;
A. Osmoregulation
B. Homeostasis
C. Ultrafiltration
D. Reabsorption
(4 x 2) (8)
1.2
Give the correct biological term for each of the following descriptions. Write only
the term next to the question number (2.1.1 to 2.1.5) in your answer sheet.
1.2.1
1.2.2
1.2.3
1.2.4
1.2.5
1.2.6
Specialised cells with filtration slits found lining Bowman’s capsule.
Tube that transport urine from the bladder to outside the body.
Blood vessel that carries purified deoxygenated blood away from the kidney.
The process by which the body eliminates metabolic wastes.
Tubes that transport urine from the kidneys to the urinary bladder.
Hormone that controls the amount of water absorbed by the kidneys and is
responsible for osmoregulation
(6 x 1) (6)
Copyright reserved
Please, turn over
Confidential Information - This is for official consumption
Life Sciences/ Excretion Grade 11
Vhembe East/ August 2026
Page 4 of 7
Question Paper
1.3.
Indicate whether each of the statements in COLUMN I applies to A only, B
Only, A and B or NONE of the items in COLUMN II. Write A only, B only, A and
B or None next to the question number (1.3.1 – 1.3.3.)
COLUMN I
1.3.1 Substances that are able to pass
through the pores on the glomerulus and
podocytes
1.3.2 Thin membrane that covers the
kidney
1.3.3 Excretory organ that produces urea
COLUMN II
A. Amino acids
B. Plasma proteins
A. Renal cortex
B. Renal medulla
A. Liver
B. Lungs
(3 x 2) (6)
TOTAL QUESTION 1: [20]
TOTAL SECTION A: [20]
SECTION B
QUESTION 2
2.1 Study the diagram of a Malpighian body and answer the questions that follow.
2.1.1
Name the network of capillaries labelled C.
(1)
2.1.2
Describe TWO structural features of part C that allow ultrafiltration to occur.
(2)
2.1.3 Supply labels for parts D and E
(2)
2.1.4. Explain the significance of the differences in diameter between structure A and structure B. (3)
Copyright reserved
Please, turn over
Confidential Information - This is for official consumption
Life Sciences/ Excretion Grade 11
Page 5 of 7
Vhembe East/ August 2026
Question Paper
2.1.5 Describe THREE functions of the kidneys. (3)
2.1.6. Describe the osmoregulation when the water level in the blood is below normal.
(5)
TOTAL QUESTION 2: [16]
QUESTION 3
Study the following information:
ADH is a chemical produced in the brain that causes the kidneys to release less water,
decreasing the amount of urine produced. A high ADH level causes the body to produce
less urine. Normally the amount of ADH in the body is higher during the night. It is normal
to urinate 1 to 2 times per night, but more frequent trips to the bathroom should send
some warning signals. Normal values for ADH ranges from between 1 to 5 µg/ml.
A higher-than-normal level may occur when too much ADH is released, either from the
brain where it is made, or from somewhere else in the body. This is called syndrome of
inappropriate ADH (SIADH). SIADH can be caused by brain injury, brain tumours, infection
in the lungs or a stroke amongst many. A lower-than normal level may indicate damage to
the hypothalamus, diabetes insipidus, excessive thirst or too much fluid in the blood
vessels.
A team of scientists decided that they want to research a group of people in the A ward of
the hospital and see how their ADH levels differ and provide explanations to why this is
possibly happening.
The population information is as follows:
•
•
•
•
10 men and 10 women
They received the same amount of water, meals and hours of sleep.
None of them could exercise to prevent excessive sweating.
All of them were monitored at a facility for 24 hours to see when they are using
the bathroom and how much urine they are producing.
The following results were obtained.
Copyright reserved
Please, turn over
Confidential Information - This is for official consumption
Life Sciences/ Excretion Grade 11
Vhembe East/ August 2026
Page 6 of 7
Question Paper
Patient
nr.
1
2
3
4
5
6
7
8
9
10
Males
ADH
Urinating frequency
levels
at night
(µg/ml)
2.4
3.3
6.2
2.5
6.9
0.5
1.2
2.2
0.43
2.8
Patient
nr.
Females
ADH levels
(µg/ml)
11
12
13
14
15
16
17
18
19
20
5.6
7.9
1.6
2.3
2.45
0.69
4.8
3.5
2.12
2.3
1
2
0
1
0
5
2
1
4
2
Urinating
frequency at
night
1
0
2
1
1
4
2
2
1
1
3.1. Provide an aim for the investigation. (2)
3.2. Identify the
3.2.1. independent variable
(1)
3.2.2. Dependent variable
(1)
3.2.3. Controlled variable
(1)
3.3. State two ways in which the scientists ensured the reliability of the results (2)
3.5 Calculate the percentage of this population group that is healthy.
(3)
3.6. Knowing the salt level in the blood of humans can provide information on their health and
lifestyle. The normal salt level in the blood is between 136 mmol/ℓ and 145 mmol/ℓ. Salt levels in
the blood below 136 mmol/ℓ are an indication of hyponatremia, and salt levels in the blood
higher than 145 mmol/ℓ are an indication of hypernatremia.
A group of people with the same diet had their blood salt levels tested.
Copyright reserved
Please, turn over
Confidential Information - This is for official consumption
Life Sciences/ Excretion Grade 11
Page 7 of 7
Vhembe East/ August 2026
Question Paper
The table below shows the results.
SALT LEVELS IN THE BLOOD (mmol/ℓ)
NUMBER OF PEOPLE
Lower than 136
5
136 to 140
15
141 to 145
21
Higher than 145
4
Draw a histogram to show the results in the table. (6)
TOTAL QUESTION 3: [14]
TOTAL SECTION B: [30]
GRAND TOTAL: [50]
Copyright reserved
Please, turn over