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LIVE: PAPER 1 EXAM QUESTIONS 29 OCTOBER 2014

Lesson Description

In this lesson we:

Revise various questions related to topics in tested in the various QUESTIONS in Paper 1

Challenge Question

Question 1

Explain how the functioning of the kidney will be affected if the ureter is blocked by a large kidney stone.

Question 2

Explain how the body responds to dehydration on a very hot day or when one is involved in strenuous exercise.

Test Yourself

Select the most correct answer from the options given. Write down only the correct letter

Question 1

The chemical substance that is used to indicate the presence of starch in leaves is …

A Benedict's solution.

B iodine solution.

C clear lime water.

D methylated spirits.

Question 2

Which substance is usually used to extract chlorophyll from leaves?

A Iodine solution

B Benedict's solution/Fehling's solutions A and B

C Alcohol

D Millon's reagent

Question 3

Which ONE of the following statements is TRUE about the relationship between a predator and its prey?

A There is intraspecific competition.

B The size of the predator population is density dependent and is controlled by the size of the prey population.

C An increased number of predators causes an increased number of prey.

D A decreased number of predators causes a decreased number of prey.

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Question 4

In humans, inhalation and exhalation are caused by movements of the …

A larynx and trachea.

B diaphragm and lung muscles.

C intercostal muscles and trachea.

D diaphragm and intercostal muscles.

Question 5

The graph below indicates the number of impala in a certain area over a specific time. The following factors could possibly be the reason for the shape of the graph:

(i) Absence of predators (ii) Individuals acclimatise to the environment (iii) Floods destroyed the habitat

Which ONE of the following combinations of factors indicate the correct sequence of events that were probably responsible for the change in numbers during the period indicated in the graph?

A (iii) (ii) (i)

B (ii) (i) (iii)

C (ii) (iii) (i)

D (i) (iii) (ii)

Question 6

Give the correct biological term for each of the following descriptions. Write only the term next to the relevant question number.

1. The phase during population growth where animals become accustomed to their new environment

2. The cell organelle concerned with the production of carbohydrates

3. The final acceptor of hydrogen during cellular respiration

4. The mesophyll tissue of the leaf where photosynthesis mainly takes place

5. Direct technique to determine population size

6. The product formed in the mouth after the enzyme has broken down cooked starch

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7. Little bones in the nasal cavity that slow down inhaled air

Question 7

Indicate whether each of the statements in COLUMN I applies to A only, B only, both A and B or none of the items in COLUMN II. Write A only, B only, both A and B or none next to the question number.

COLUMN I COLUMN II

1 The digestive juice/s that enter/s the duodenum

A: Pancreatic juice

B: Bile

2 Transports both oxygen and carbon dioxide in blood

A: Haemoglobin

B: Bicarbonate ions

3 The type of epithelium that lines the

alveolus

A: Squamous epithelial

B: Ciliated epithelial

4. Carbohydrate that is stored in the

mammalian muscle and liver

A: Glucagon

B: Glycogen

5. The acid that accumulates in muscle cells during strenuous

exercise

A: Lactic acid

B: Alcohol

Exam Questions

Question 1

(Adapted from paper 1 SG nated prep 2010)

The apparatus below was set up by a learner. She made sure that the test tube was initially completely full of water.

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1.1 What is the AIM of this investigation? (1)

1.2 Why was the test tube filled with water? (2)

1.3 Why was it necessary to leave the apparatus near a warm, sunny window? (1)

1.4 Name the gas that is present in the bubbles. (2)

1.5 Describe ONE way in which you would test for the gas named in QUESTION 1.4. (1)

Question 2

(Adapted P1 SG nated 2010)

The diagram below illustrates the internal structure of a leaf. Answer the questions based on it.

2.1 Identify parts A, B and E, as well as cells C and F. (5)

2.2 State the role of each of the following for the process of photosynthesis:

(i) B

(ii) D

(iii) E (3)

2.3 Tabulate TWO differences between cells C and F. (1)

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Question 3

(Adapted from paper 1 sg 2010 nated)

3.1 Study the diagram below and then answer the questions that follow.

3.1.1 Give labels for parts A, B, and C respectively. (3)

3.1.2 Describe ONE major difference between the composition of the blood in vessel D and vessel E. (3)

3.1.3 Name TWO features of the structure shown in the drawing which makes it efficient for gaseous exchange in humans. (1)

3.1.4 Describe the mechanism of exhalation. (2)

3.2 The graph below represents the results of an investigation using a spirometer. A spirometer is an instrument used to measure the amount of air that enters and leaves the lungs during breathing.

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3.2.1 How much air is taken into the lungs in one breath during deep breathing? (2)

3.2.2 How many breaths did the person take in the first 60 seconds? (2)

3.2.3 Name

(i) TWO muscles in the human body which are actively involved in normal inhalation. (2)

(ii) the part of the human brain responsible for regulating the breathing rate. (1)

Question 4

(Adapted from Biology P2 hg 2011)

4.1 Study the diagram below of a longitudinal section through a human kidney and answer the questions that follow.

4.1.1 Identify parts D, E and F. (3)

4.1.2 Why, in an actual specimen, is region B darker in colour compared to region C? (2)

4.1.3 Identify part A and state ONE function of it. (2)

(Adapted from Biology P2 hg 2010)

4.2 The following graph indicates the concentrations of certain substances as they move through the various regions of the nephron. Study the graph and answer the questions that follow.

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4.2.1 Name the regions indicated by A and B. (2)

4.2.2 Which of the substances indicated on the graph is not excreted as part of urine? (1)

4.2.3 Which product, according to the graph, occurs in a higher concentration in urine than in the blood entering the kidney? (1)

4.2.4 Explain the changes in the glucose concentration during its movement through region B. (5)

4.2.5 Explain the mechanism that leads to a decrease in water concentration in the distal convoluted tubule. (6)

Question 5

(Adapted from paper 1 prep Gauteng 2014)

5.1 A normal blood glucose level is 1,0 mg/cm3 and a normal insulin level is 0,5 mg/cm3. A group of people with normal levels of blood glucose and blood insulin were tested over a period of 5 hours.

The average values were calculated and are indicated in the graph below.

Study the graph and answer the questions that follow.

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5.1.1 What is the glucose level at 3 hours after the start of the investigation? (2)

5.1.2 Explain the relationship between insulin and blood glucose by referring to the graphs. (3)

5.1.3 Name the organ in the body which produces insulin.

5.1.4. Explain the homeostatic mechanism that controls the glucose levels in the body.

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(Adapted from hg p1 2010)

5.2 The diagram below shows parts of the human digestive system and its associated organs. Study the diagram and answer the questions that follow.

5.2.1 Give the LETTER and NAME of the part where

(a) bile is temporarily stored.

(b) the hormones that control the blood glucose level are secreted. (4)

5.2.2 Name any TWO types of enzymes that are found in D and briefly describe the role of each. (4)

5.3 List

(a) TWO functions of bile.

(b) THREE functions of water in the movement of food along the digestive system.

5.4 Name TWO substances that can be converted into other substances inside the organ marked A. (2)

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Question 6

(Adapted from HG biology P1 2008)

The schematic representation below shows the relationship between two biological processes in a plant cell.

Answer the questions that follow.

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6.1 Identify organelles X and Y. (2)

6.2 Name the biological process that takes place in the following organelle:

(a) Organelle X

(b) Organelle Y (2)

6.3 The arrows 1 to 4 indicate the movement of gases into and out of the organelles.

Name the gases represented by:

(a) 1

(b) 2

(c) 3

(d) 4

6.4 Name the pigment found in the part labelled B. (1)

6.5 State the function of the pigment named in QUESTION 6.4. (1)

6.6 Name the process that takes place in the part labelled A. (1)

6.7 Describe the biological importance of the process that takes place in organelle Y. (3)

Question 7

(Adapted from Paper Nated sg 2010)

7.1 The table below shows the changes in population size of bacteria grown in a petri dish in a laboratory at 20 °C. Study the table and answer the questions that follow.

7.1.1 Use the data from the table above and draw a line graph to illustrate the growth curve of the bacteria population. (11)

7.1.2 Identify and explain the different phases of the growth curve:

(a) Between 0 and 2 hours

(b) Between 2 and 12 hours

7.1.3 Would you regard competition as a density-dependent factor or a density-independent factor? Give a reason for your answer.

7.1.4 What is the possible carrying capacity of the bacteria culture?

7.2 A learner wanted to know how many fish were in a dam. He caught 10 fish and marked them by clipping out a small section of their tail fin. He then released them back into the dam. A few days later he caught 20 fish, of which 5 had been marked.

7.2.1 Calculate the total number of fish in the dam by using the following formula:

P = F x S

M

P = Total number of fish in the population

F = Number of fish caught and marked in the first catch

S = Number of fish caught in the second catch

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M = Number of marked fish in the second catch (3)

7.2.2 Name the method used in QUESTION 7.1.1. (1) 7.2.3 Describe THREE requirements which must be complied with to obtain valid

results in the method mentioned in QUESTION 7.2.2. (3)

7.3 Study the graph below and answer the questions that follow.

7.3.1 Which population-regulating factor is illustrated by this graph? (2)

7.3.2 Is this regulating factor named in QUESTION 7.3.1 a densitydependent or a density-independent factor? Give a reason for your answer. (3)

7.3.3 How many of the following were there in 1966?

(i) Rabbits

(ii) Wild dogs (2)

7.3.4 What is the maximum number of rabbits that have ever survived in this environment? (1)

7.3.5 Will the rabbit population increase or decrease when there is a small number of wild dogs? Explain your answer. (3)

Question 8

(Adapted from Paper 1 hg 2010 nated 2010)

The higher concentration of CO2 created in the cells and tissue fluid as a result of more exercise, causes a drop in the blood pH so that it becomes slightly acidic. This situation is not favourable for the functioning of the organism as a whole. Describe the mechanism by which the breathing system will bring about a homeostatic balance to correct/normalise this situation.

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Answers

Challenge Question

Question 1

Urine will not be able to leave renal pelvis/kidney

causing swelling of the kidney tissue

and an accumulation of fluid in the renal tubules

Renal failure / kidney malfunctioning may result

Infection may also result

May also lead to pain and bleeding

Question 2

When the volume of water in the blood decreases

Osmoreceptors in the hypothalamus are stimulated and the messages are sent to the hypophysis / pitituary gland to secrete more ADH which increases the permeability of the walls of the distal convoluted tubules and collecting ducts

This causes more water to leave the convoluted tubules through osmosis

The amount of water in the blood increases and more concentrated urine is formed and less water is excreted by the body.

Test Yourself 1. B

2. C

3. B

4. D

5. B

6 1. Lag

2. Chloroplast

3. Oxygen

4. Palisade

5. Census

6. Maltose

7. Turbinate

9. a) Both

b) A ONLY

c) A ONLY

d) B ONLY

e) A ONLY

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Exam Questions

Question 1

1.1 To show that oxygen is released during photosynthesis

1.2 To make the apparatus airtight / want to find out whether any gas is produced therefore must not have any gas to start with

1.3 To enable photosynthesis to take place

1.4 oxygen

1.5 - Remove the test tube from the funnel

- Insert a glowing end of a wood splint into the test tube

- Glowing splint would glow brighter or burst into a flame

Question 2

2.1 A Palisade tissue

B Cuticle

E Intercellular air space(s)

C Epidermal cell

F Guard cells

2.2 (i) (Transparent) allows light to pass through /prevents excessive loss of water

(ii) Absorbs sunlight / contain chlorophyll for photosynthesis

(iii) Allows movement of gases / water

2.3

Question 3

3.1.1 A - Bronchiolus

B - Alveolus

C - Blood capillary/arteriole

3.1.2 - Blood in D is deoxygenated while blood in E is oxygenated

OR

- Blood in D contains less oxygen/more CO2 while blood in E contains more oxygen/less CO2

3.1.3 - numerous alveoli/large surface area

- presence of blood capillaries

- thin walls

- moist surface

3.1.4 - diaphragm relaxes and

- becomes dome-shaped/convex

- external intercostal muscles relax

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- internal intercostals muscles contract

- rib cage is lowered

- abdominal muscles contract during vigorous breathing

- total volume of the thoracic cavity decreases and

- pressure on the lungs increases

- Air rich in carbon dioxide is forced out of the lungs

3.2.1 3 litres

3.2.1 6 breaths

3.2.3 (i) intercostals muscles

Diaphragm

(ii) Medulla oblongata

Question 4

4.1.1 D: Renal vein

E: (Renal) pelvis

F: (Renal) calyx

4.1.2 B contains the glomeruli /more capillaries /Malpighian bodies

OR

C contains no glomeruli /Malpighian bodies /fewer capillaries

4.1.3 (Renal) capsule

Protects inner parts of kidney

4.2.1 A - Bowmans capsule

B - Proximal convoluted tubule

4.2.2 Glucose

4.2.3 Urea

4.2.4 - When entering it is in a high concentration

- When leaving it is in a low concentration

- Active reabsorption takes place against a concentration gradient from a low concentration to a high concentration

- The transport mechanism requires energy. This is supplied by the epithelial cells.

- Some of the glucose is used by the nephrons to supply energy

4.2.5 - The volume of water in the blood decreases

- Osmoreceptors in the hypothalamus are stimulated and the messages are sent to the hypophysis / pitituary gland to secrete more ADH which increases the permeability of the walls of the distal convoluted tubules and collecting ducts

- This causes more water to leave the convoluted tubules through osmosis

- The amount of water in the blood increases and more concentrated urine is formed and less water is excreted by the body.

Question 5

5.1.1 1,4mg/cm3

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5.1.2 An increase in glucose level results in an increase in the level of insulin, while an increase in insulin causes glucose levels to decrease

5.1.3 Pancreas

5.1.4 - When abnormal levels of glucose are detected

- by the pancreas,

- the Islets of Langerhans secretes hormones

- into the bloodstream

When blood glucose level rises

- Insulin is secreted

- to decrease the blood glucose level

- back to normal

- insulin secretion is then inhibited

When blood glucose level falls

- Glucagon is secreted

- to increase the blood glucose level

- back to normal

glucagon secretion is then inhibited

5.2.1 (a) B – gall bladder

(b) C - pancreas

5.2.2 Carbohydrases, proteases and lipases

5.3 (a) Emulsifies fat; fluidity; alkalinity; assists in the absorption of the fat soluble vitamins A, D, E and K

(b) - acts as a lubricant

- allows for peristaltic movement

- keeps tissue moist, soft and pliable

- is a fluid and allows easy movement of food

5.4 - glucose

- amino acids

- fats

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Question 6

6.1 X – Mitochondria Y – chloroplast/plastid

6.2 (a) Cellular respiration

(b) photosynthesis

6.3

6.4 Chlorophyll

6.5 Traps radiant energy

6.6 Dark phase of photosynthesis

6.7 release of oxygen,

uptake of carbon dioxide from atmosphere, food

production (trapping energy)

Question 7

7.1.1

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7.1.2 (a) Lag phase/ establishment phase

Bacteria acclimitasing to environment / not enough mating partners

(b) Geometric phase / logarithmic / exponential/accelerating growth phase

Bacteria population increase rapidly/ there is no limitation

on mating partners / little or no environmental resistance

7.1.3 Density-dependent factor – since size of population depends on competition for the same source

7.1.4 985 bacteria

7.2.1 10 X 20

5

= 40 fish

7.2.2 mark-recapture/indirect method

7.2.3 - the mark must last throughout the period of the investigation

- the mark must not affect the animal’s behaviour

- the population must remain constant

- animals must mix completely with the entire population

- animals must not be trap-shy or trap-addicted

- chances of animal being trapped must not change with age

7.3.1 predation/ predator-prey

7.3.2 density-dependent

the number of prey depends on the number of predators

7.3.3 (i) 50

(ii) 200

7.3.4 500

7.3.5 Increase because there are less wild dogs to prey on the rabbits

Question 8

The chemoreceptors in the walls of the aorta and the carotid

Vessels and in the medulla oblongata are able to sense changes in the level of CO2 (and not oxygen).

Nerve impulses are then sent to the brain/the medulla oblongata which sends feedback impulses to:

the breathing muscles/ intercostals muscles/diaphragm

and abdominal muscles so they can rapidly contract to

speed up the rate/faster and deeper breathing as a

result of this, more oxygen is taken in from the

atmosphere and CO2 is released to the atmosphere

the heart beat increases

in order to accelerate the transport of CO2 to the lungs

where it will be expelled to the atmosphere

more oxygen from the lungs is taken into the blood

The pH / from acidic of the blood changes back to normal

This is why even long after an exercise, one still breathes heavily