instructions and information - grey college

Life Sciences P1/Grade 12 2 September 2019

Copyright reserved Please turn over

INSTRUCTIONS AND INFORMATION Read the following instructions carefully before answering the questions. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Answer ALL the questions. Write ALL the answers in the ANSWER BOOK. Start the answers to EACH question at the top of a NEW page. Number the answers correctly according to the numbering system used in this question paper. Present your answers according to the instructions of each question. Do ALL drawings in pencil and label them in blue or black ink. Draw diagrams, tables or flow charts only when asked to do so. The diagrams in this question paper are NOT necessarily drawn to scale. Do NOT use graph paper. You must use a non-programmable calculator, protractor and a compass where necessary. Write neatly and legibly.



SECTION A QUESTION 1 1.1 Various possible options are provided as answers to the following questions.

Choose the answer and write only the letter (A to D) next to the question number (1.1.1 to 1.1.10) in the ANSWER BOOK, for example 1.1.11 D.

1.1.1 In which part of the female reproductive system does implantation

take place? A Ovary B Fallopian tube C Endometrium D Cervix

1.1.2 The graph below shows the concentration of dissolved oxygen at

different points along a river.

At which point on the graph was sewage most likely to have been

poured into the river? A 1 B 2

C 3

D 4

Co

nc

en

tra

tio

n o

f

dis

so

lve

d o

xy

ge

n

Distance along the river



1.1.3 Below is a list of events that occur during hearing:

(i) Tympanic membrane and ossicles vibrate (ii) Pinna collects sound waves

(iii) Organ of Corti is stimulated (iv) Auditory nerve transmits impulses to the brain

1.1.4 Eutrophication reduces the quality of water because it …

A promotes an increase in decomposers in aquatic food webs.

B causes dams, rivers and lakes to dry up. C promotes a sustained population growth of insect larvae.

D causes a decrease in the temperature of the water. 1.1.5 The list below refers to changes that occur in the human body:

(i) Growth of hair in the armpits

(ii) Widening of the hips (iii) Sharpening of the voice

(iv) Broadening of chest and shoulders

Which of the above can be considered as changes occurring in the male body during puberty?

A (i), (iii) and (iv) only

B (i) and (iv) only C (i) only

D (i), (ii), (iii) and (iv) 1.1.6 Which ONE of the following is likely to happen in an athlete during

a 200-metre race?

A A decrease in breathing rate

B An increase in blood flow to the muscles C A decrease in the heart rate

D An increase in blood flow to the intestines

Which ONE of the following represents the correct sequence of events?

A (i), (ii), (iii) and (iv)

B (ii), (i), (iii) and (iv) C (ii), (iv), (iii) and (i)

D (iv), (iii), (i) and (ii)



1.1.7 Which ONE of the following methods may be used to manage solid waste disposal of nuclear waste?

A Recycling

B Thick steel drums buried underground Landfill sites Large dams

C

D 1.1.8 The homeostatic function of the kidney can be affected by damage

to the hypothalamus because … A the level of glucose will drop.

B cellular metabolism will increase. C production of ADH will be affected.

D blood flow to the kidney will increase.

1.1.9 Which ONE of the following pairs CORRECTLY matches a gland and the hormone it secretes?

GLAND HORMONE

A Adrenal gland Aldosterone

B Ovary FSH

C Testis Progesterone

D Hypothalamus Adrenalin

1.1.10 A person hears a gunshot. In the human nervous system this will be registered as …

A an impulse.

B an effector. C a response.

D a stimulus. (10 x 2) (20)



1.2

Give the correct biological term for each of the following descriptions. Write only the term next to the question number (1.2.1 to 1.2.9) in the ANSWER BOOK.

1.2.1

The use of resources in such a way that they are available for future generations

1.2.2

Behavioural pattern where parents spend time and energy on the feeding and protection of their offspring

1.2.3

The type of egg that is laid by reptiles and birds

1.2.4

The structure that connects the ovary to the uterus

1.2.5

A rapid, automatic response to an external stimulus

1.2.6 The hormone that stimulates milk production in humans

1.2.7 1.2.8

The sum of all CO2 emissions resulting from human activities within a given period of time The organ that deposits semen into the female body

1.2.9 A gas produced in landfills that can be used for cooking (9 x 1) (9)

1.3 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 (1.3.1 to 1.3.4) in the ANSWER BOOK.

COLUMN I COLUMN II

1.3.1 Factors that decrease water availability

A: A Destruction of wetlands B Alien plants

1.3.2 Characteristic of ovovivipary A: A Placenta formed B: B Eggs are preyed upon by

Predators

1.3.3 Responsible for the production of gametes

A: A Meiosis B Gametogenesis

1.3.4 The structure that receives a stimulus and converts it into an impulse

A: A Motor neuron B Receptor

(4 x 2) (8)



1.4 The diagram below shows a part of the central nervous system.

Give the LETTER and the NAME of the part that:

1.4.1 1.4.2 1.4.3 1.4.4

Controls muscle tension to maintain balance Interprets what you hear Is an endocrine gland Regulates heart beat and breathing

(2)

(2)

(2)

(2) (8)

A

B

C

F

D

E



1.5 The diagram below shows a neuron.

1.5.1

1.5.2 1.5.3

What type of neuron is illustrated? Provide labels for parts A and B. Give the LETTER and NAME of the structure that is affected when a person suffers from multiple sclerosis.

(1)

(2)

(2) (5)

TOTAL SECTION A: 50

Direction of impulse

A

E

C

D

B



SECTION B QUESTION 2 2.1 The diagrams below represent two different phases of meiosis in an organism.

2.1.1 2.1.2 2.1.3 2.1.4 2.1.5 2.1.6 2.1.7

Identify: (a) A (b) B Identify the phases represented by: (a) Diagram I

(b) Diagram II State the number of chromosomes that were present in the original cell at the start of meiosis. Give the name of the organ in a male where meiosis occurs. Describe the process responsible for the appearance of the chromosomes as shown in region C. Identify the phase of meiosis during which the process referred to in QUESTION 2.1.5 occurs. State TWO reasons why meiosis is important.

(1)

(1)

(1)

(1)

(1)

(1)

(4)

(1)

(2) (13)

A

DIAGRAM I DIAGRAM II

C

B



2.2 Read the extract below.

CAVENDISH BANANAS ARE AT RISK The banana is the world’s most popular fruit and almost all bananas sold across the world belong to the so-called Cavendish subgroup and are genetically nearly identical. Bananas could, however, soon become an endangered fruit due to a fungus named TR4 that threatens to wipe out crops across the globe. The fungus attacks the plant's leaves, causing cell death that affects photosynthesis. Cavendish varieties have shown little resistance against TR4. In an effort to control the disease, farmers use up to 50 applications of chemicals on one crop every year. According to scientists, banana farmers will have to make ''drastic strategy changes'' to prevent the spread of the fungus.

2.2.1

2.2.2 2.2.3 2.2.4

Describe how the TR4 fungus affects the banana plants. Define monoculture. Describe how the practice of monoculture helps the spread of the TR4 fungus. To control the disease, farmers use up to 50 applications of chemicals on one crop every year. Explain TWO consequences of using such high amounts of chemicals on the banana plants each year. (2 x 2)

(2)

(2)

(3)

(4) (11)

2.3 Differentiate between the greenhouse effect and global warming. (4)



2.4 An experiment was conducted to determine the effect of gibberellins on the growth of dwarf pea plants. The following procedure was followed:

• Twenty dwarf pea seeds were used.

• The seeds were planted into two trays of ten seeds each (A and B).

• The plants were watered every second day.

• After the plants reached an average of two to three centimetres in length, the plants in tray A were sprayed with distilled water and those in tray B were sprayed with gibberellins.

• The height of the plants was measured every third day for a period of 13 (thirteen) days and the average was calculated.

• The table below shows the results that were recorded.

DAY NUMBER

AVERAGE HEIGHT (cm)

Distilled water Gibberellins

1 30 30

4 43 102

7 50 112

10 69 142

13 75 148

2.4.1 Identify the: (a) Independent variable (b) Dependent variable

(1)

(1)

2.4.2 Explain why they used distilled water and not ordinary tap water.

(2)

2.4.3 State TWO factors that should have been kept constant during the investigation.

(2)

2.4.4 On the same system of axes, draw TWO line graphs to represent

the data in the table.

(6) (12) [40]



QUESTION 3

3.1 Study the diagram of a sperm cell.

3.1.1 Give the LETTER only of the part that contains:

(a) Many mitochondria

(b) A haploid number of chromosomes

(1)

(1)

3.1.2 Explain the presence of a high number of mitochondria in the part named in QUESTION 3.1.1 (a).

(3)

3.1.3 Describe spermatogenesis.

(4)

3.1.4 A healthy sperm cell is able to swim about 5 mm per minute. If the

distance from the cervix to the end of the Fallopian tube is 20 cm, how long will it take for the sperm cell to reach the ovum at the end of the Fallopian tube? Show ALL calculations.

(3) (12)

A B C D



3.2 The diagram below represents an ovary showing some of the changes taking place during the ovarian cycle of a female.

3.2.1 3.2.2

Give the name of: (a) The process taking place at B (b) The hormone responsible for the process at B If fertilisation does not take place, structure A degenerates. Explain the implications of this for the ovarian cycle.

(1)

(1)

(3) (5)

3.3 Tabulate TWO differences in the composition of the blood in the umbilical vein and the umbilical artery. (5)

A

B



3.4 Study the diagram and the graph.

Section of the human eye

3.4.1 3.4.2 3.4.3 3.4.4

3.4.5

Explain ONE way in which part A is suited for its function. Which NUMBER (1 - 4) on the graph represents B in the diagram? Give a reason for your answer to QUESTION 3.4.2.

Name the part of layer C in the diagram which corresponds to

number 3 on the graph.

People between the age of 20 and 40 using glasses are advised

to change them every two years after retesting their eyesight.

Explain why this would be necessary.

(2)

(1)

(2)

(1)

(3) (9)

Clarity of image at different areas on the retina

1 2 3 4

Re

lati

ve

cla

rity

of

the

im

ag

e

A

B

C

Areas on the retina



3.5 The blood glucose level of a healthy person is approximately 100mg/100mℓ. The blood glucose levels of an individual were monitored over a period of eight hours and the results plotted on the graph below.

3.5.1 3.5.2 3.5.3 3.5.4

Suggest why the blood glucose levels were high at 08:00 and 13:00. Describe the process in the body that is responsible for the trend in the graph between 08:00 and 10:00 and between 13:00 and 15:00. What evidence in the graph indicates that this individual is not diabetic? Explain your answer to QUESTION 3.5.3. TOTAL SECTION B:

(1)

(4)

(1)

(3) (9)

[40]

80

BLOOD GLUCOSE LEVELS OVER A PERIOD OF 8 HOURS

Time

Blo

od

glu

co

se

le

ve

ls (

mg

/10

0m

l)



SECTION C QUESTION 4 Imran Tahir, a South African cricket player, bowls during a cricket match on a hot day. Describe how Tahir’s temperature was lowered on the hot day, how he maintained his balance and equilibrium during his bowling and the role of hormones in maintaining his energy levels.

NOTE: NO marks will be awarded for answers in the form of flow charts, tables

or diagrams.

TOTAL SECTION C:

GRAND TOTAL: 20 150

Content: Synthesis:

(17) (3) (20)

instructions and information - grey college

Documents