Post on 09-Aug-2020
11581
*ABY11*
TIME2 hours 15 minutes.
INSTRUCTIONS TO CANDIDATESWrite your Centre Number and Candidate Number in the spaces provided at the top of this page.You must answer the questions in the spaces provided. Do not write outside the boxed area on each page or on blank pages. Complete in black ink only. Do not write with a gel pen.Answer all nine questions.
INFORMATION FOR CANDIDATESThe total mark for this paper is 100.Section A carries 82 marks. Section B carries 18 marks.Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question.You are expected to answer Section B in continuous prose.Quality of written communication will be assessed in Section B (Question 9).
Centre Number
Candidate Number
*ABY11*
New
Specification
*40ABY1101*
ADVANCEDGeneral Certificate of Education
2018
BiologyAssessment Unit A2 1assessing
Physiology, Coordination andControl, and Ecosystems
[ABY11]THURSDAY 7 JUNE, MORNING
*40ABY1101*
*40ABY1102*
*40ABY1102*
11581
BLANK PAGE
DO NOT WRITE ON THIS PAGE
*40ABY1103*
*40ABY1103*
11581[Turn over
Section A
1 In many plants, flowering is controlled by day length. This is known as photoperiodism.
(a) Name the light-sensitive pigment involved in photoperiodism.
___________________________ [1]
(b) State the location of this light-sensitive pigment in the plant.
___________________________ [1]
(c) Complete the diagram using the most appropriate words or terms.
P660
light
light[3]
*40ABY1104*
*40ABY1104*
11581
2 A typical cone cell from the retina of a mammalian eye is shown in the diagram below.
Discs of membrane with lightsensitive pigment (iodopsin)
Mitochondria
Golgi apparatus
Rough endoplasmic reticulum
Nucleus
Vesicles containing neurotransmitters
Outer segment
Inner segment
(a) Identify the structure labelled in the diagram which:
1. synthesises protein _______________________________________________
2. modifies protein ______________________________________________ [1]
© Principal Examiner
*40ABY1105*
*40ABY1105*
11581[Turn over
(b) With reference to the diagram, suggest and explain how the cell is adapted forits function.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [3]
*40ABY1106*
*40ABY1106*
11581
3 Within an ecosystem, certain populations are r-selected, while others are K-selected.
(a) Define the term population.
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [1]
An algal population in a pond is an example of an r-selected population.
(b) On the axes below, sketch an appropriate growth curve for an algal population ina pond from April to December. The population from January to March has beencompleted for you.
Jan Feb Mar Apr May
Time/Month
Jun Jul Aug Sept Oct Nov Dec
Num
ber o
f alg
ae
[1]
*40ABY1107*
*40ABY1107*
11581[Turn over
(c) List three characteristics of r-selected species.
1. _______________________________________________________________
_________________________________________________________________
2. _______________________________________________________________
_________________________________________________________________
3. _______________________________________________________________
______________________________________________________________ [3]
*40ABY1108*
*40ABY1108*
11581
BLANK PAGE
DO NOT WRITE ON THIS PAGE
*40ABY1109*
*40ABY1109*
11581[Turn over
4 The human urinary system is shown in the diagram below. One of the kidneys shown is dissected.
Aorta
AB
C
D
E
(a) Identify A–E
A ___________________________
B ___________________________
C ___________________________
D ___________________________
E ___________________________ [3]
© Principal Examiner
*40ABY1110*
*40ABY1110*
11581
(b) The concentrations of four substances in different regions of the nephron weremeasured. Their concentration compared to that in the glomerular filtrate wasthen calculated. The results are shown in the graph below.
PCT Loop of Henlé DCT Collecting duct
Less
con
cent
rate
dM
ore
conc
entra
ted
urea
chloride
sodiumglucose
Region of nephron
(i) Describe and explain the trend shown for glucose in the proximal convolutedtubule (PCT).
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
*40ABY1111*
*40ABY1111*
11581[Turn over
(ii) Explain the changes in the concentrations of ions (sodium and chloride)along the loop of Henlé.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [4]
Antidiuretic hormone (ADH) has a role in osmoregulation of the blood.
(c) (i) State the precise location of osmoreceptor cells in the brain.
______________________________________________________________ [1]
(ii) State precisely where ADH is released into the bloodstream.
______________________________________________________________ [1]
*40ABY1112*
*40ABY1112*
11581
The effect of intensity of exercise on the concentration of ADH in blood plasma was investigated in a group of students. They carried out exercises of different intensities for the same length of time, and the ADH concentration in each student was measured one hour after the exercise. The results of the investigation are summarised in the graph below.
500 100Intensity of exercise/arbitrary units
150 200 250
1
0
2
3
4
5
6M
ean
bloo
d pl
asm
a A
DH
conc
entra
tion/
arbi
trary
uni
ts
(d) (i) Identify one other controlled variable appropriate for this investigation.
_________________________________________________________________
______________________________________________________________ [1]
*40ABY1113*
*40ABY1113*
11581[Turn over
(ii) Describe and explain the trend shown and the consequence of this onkidney function.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [4]
*40ABY1114*
*40ABY1114*
11581
5 The energy flow through a cow is summarised in the diagram below.All values are given in kJ year –1.
Faeces (F)54.39×106
Urine (U)0.08×106
Consumed (C)91.78×106
Respiration (R)34.68×106
Production (P)
(a) (i) Using the letters shown (C, F, R and U) write a formula which will allowproduction (P) to be calculated.
P = __________________________________ [1]
(ii) Calculate the value for production (P).
__________________________________ ×106 kJ year –1 [1]
© Principal Examiner
*40ABY1115*
*40ABY1115*
11581[Turn over
(iii) The productivity of grass is 22 275 kJ m –2 year –1. A different cow feeding on9500 m2 of grassland has a production of 1.6×106 kJ year –1.
Calculate the percentage of the energy in the grass that is used inproduction in this cow.(Show your working.)
_________________% [2]
*40ABY1116*
*40ABY1116*
11581
(b) In an investigation, the same type of crop was grown in two adjoining fields,A and B. Each field was subdivided into six plots of one hectare (ha) each.A different mass of fertiliser was added to each plot.
After six weeks, samples of crop plants from each plot were collected and theirmass in kilograms (kg) was measured. The results are shown in the table below.
Plot Mass of fertiliser added to plot/kg ha –1
Mass of crop/kg m –2
Field A Field B
1 0 14.2 6.2
2 10 16.6 9.7
3 20 17.3 13.1
4 30 17.5 16.2
5 40 17.5 17.1
6 50 17.5 17.1
(i) Explain the change in the mass of crop produced in field B when the massof fertiliser added increased from 0 to 20 kg ha –1.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
*40ABY1117*
*40ABY1117*
11581[Turn over
(ii) During the previous year, field A had been used for grazing cattle. Field Bhad been used to grow the same type of crop in each year. The table showsthat when no fertiliser was added, the mass of crop from field A was higherthan from field B. Suggest an explanation for this difference.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
(iii) State one advantage and one disadvantage of using artificial (inorganic)fertiliser on a field.
Advantage: ______________________________________________________
_________________________________________________________________
Disadvantage: ____________________________________________________
______________________________________________________________ [2]
*40ABY1118*
*40ABY1118*
11581
6 MRSA is a strain of the bacterium Staphylococcus aureus and is resistant to the antibiotic methicillin.
(a) (i) State the kingdom to which bacteria belong.
______________________________________________________________ [1]
(ii) Genes for antibiotic resistance are commonly found within structures outsidethe main bacterial chromosome. Name these structures.
___________________________ [1]
*40ABY1119*
*40ABY1119*
11581[Turn over
The number of deaths involving MRSA in Northern Ireland during the period 2006 to 2015 is shown in the graph below.
0
10
20
30
40
50
60
70
80
90
100
Year
Num
ber o
f dea
ths
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
(b) Describe and suggest reasons for the trends shown from 2008 to 2015.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [3]
"Source: NISRA : Website: www.nisra.gov.uk" © Crown Copyright
*40ABY1120*
*40ABY1120*
11581
(c) Some human diseases are caused by viruses that were originally found in othermammals, e.g. bats. These mammals can be referred to as ‘reservoirs’ for thevirus concerned.
The map below shows both the locations of recent outbreaks of human diseasesknown to be caused by a number of these viruses and the distribution range ofbats of the genus Pteropus.
KEY
Outbreaks of viral disease
Range of Pteropus
(i) Using the map, suggest why Pteropus bats may have been identified asreservoirs for these viruses.
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [1]
(ii) Suggest two reasons why viruses which are carried by bats may passrelatively easily to human populations.
1. _______________________________________________________________
_________________________________________________________________
2. _______________________________________________________________
______________________________________________________________ [2]
Nipah Virus Distribution Map © Centers for Disease Control and Prevention
*40ABY1121*
*40ABY1121*
11581[Turn over
Once a virus is transmitted to humans, it may mutate so that it can spread more easily to other humans. This could potentially cause a pandemic.
(d) (i) Define the term ‘pandemic’.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
(ii) The viruses referred to in part (c) are retroviruses. State the type of geneticmaterial contained within retroviruses and explain the significance of theenzyme reverse transcriptase in retroviruses.
Genetic material ______________________________ [1]
Significance of enzyme _________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
(iii) State how an inhibitor of reverse transcriptase might help to preventa pandemic.
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [1]
*40ABY1122*
*40ABY1122*
11581
7 Synapses allow coordination and integration in the nervous system. The diagram below shows how two neurones, A and B, synapse with a third neurone, C.
Neurone A releases the neurotransmitter acetylcholine and is excitatory. Neurone B releases a different neurotransmitter called GABA (gamma-aminobutyric acid) and is inhibitory. Neurone C is the post-synaptic neurone. Binding of GABA results in the movement of negative ions into the post-synaptic neurone.
A B
C
Post-synaptic neurone
(a) (i) Explain how the release of acetylcholine from neurone A causes anexcitatory post-synaptic potential (EPSP) in the post-synaptic neurone C.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
© Principal Examiner
*40ABY1123*
*40ABY1123*
11581[Turn over
(ii) Suggest why the arrival of an impulse in neurone B reduces the possibilityof an EPSP forming in the post-synaptic neurone.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
(iii) The enzyme acetylcholinesterase acts in the synaptic cleft. Explain the roleof this enzyme.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
*40ABY1124*
*40ABY1124*
11581
DFP is a pesticide which interacts with the active site of acetylcholinesterase. It is a neurotoxin, causing paralysis and resulting in the death of an insect pest.
(b) (i) Suggest how DFP affects the post-synaptic neurone of an insect.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
DFP has been useful in controlling insect pest populations in the past. However, some populations now appear to have become resistant to DFP.
(ii) Explain how a population may become resistant to a pesticide such as DFP.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
*40ABY1125*
*40ABY1125*
11581[Turn over
BLANK PAGE
DO NOT WRITE ON THIS PAGE
(Questions continue overleaf)
*40ABY1126*
*40ABY1126*
11581
8 Young rabbits often die of a disease called rabbit haemorrhagic disease (RHD), caused by a virus. To learn more about this disease, young mice were used as models. Scientists investigated the survival rates of young mice following infection with the virus at different ages. The results are shown in the graph below.
0
10
20
30
40
50
60
70
80
90
100
Mou
se s
urvi
val/%
0 1 2 3 4 5 6 7 8 9 10Age of mice at infection/weeks
(a) (i) Given that young mice feed on milk produced by their mother, suggest apossible explanation for the high survival rates of mice infected during the three weeks following birth.
_________________________________________________________________
______________________________________________________________ [1]
(ii) Suggest a reason why mice were used as disease models forthis investigation.
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [1]
*40ABY1127*
*40ABY1127*
11581[Turn over
(b) The virus can enter the cells in the respiratory and digestive tracts, using amolecule found in the plasma (cell surface) membrane of these cells. The virusbinds to this molecule and then enters the host cell. Production of this moleculeincreases with age.
Most damage associated with RHD occurs to the cells of the liver. Liver cells donot have this molecule on their plasma membrane.
Using the information provided:
(i) Suggest another possible reason for the high survival rate of mice infectedduring the three weeks following birth.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
(ii) Explain why there is thought to be more than one mechanism by which thevirus can enter a cell.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
*40ABY1128*
*40ABY1128*
11581
A test for RHD virus in rabbits detects the presence of RHD antibodies in the blood serum of infected rabbits. The technique is summarised below.
Step 1
Step 2
Step 3
Step 4
antigen
antibody
antibody with attached enzyme
substrate
Antigens are attached to the wall of a well(a small chamber)
Serum from a rabbit is added. If the serumcontains RHD antibodies these will bind to the antigens
A second antibody (with attached enzyme) is added and binds to the original RHD antibodies. The enzyme is only activated if the second antibodies are attached to RHD antibodies
A substrate is added which binds to activated enzymes and a coloured productis released
(c) (i) Define the term antigen.
_________________________________________________________________
______________________________________________________________ [1]
© Principal Examiner
*40ABY1129*
*40ABY1129*
11581[Turn over
(ii) Describe and explain the result you would expect if the rabbit was notinfected by the RHD virus.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [3]
It is sometimes necessary to carry out a dilution of the serum sample using a buffer.
(iii) Calculate the volume of undiluted serum in µl (1000 µl = 1 ml), which mustbe added to a buffer to give 10 ml of solution at a final dilution of 1/500.(Show your working.)
_________________ µl [2]
*40ABY1130*
*40ABY1130*
11581
BLANK PAGE
DO NOT WRITE ON THIS PAGE
*40ABY1131*
*40ABY1131*
11581[Turn over
(iv) Describe an immune response that may occur in rabbits infected withRHD virus.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [4]
In some countries rabbit farming is an important activity, providing a source of meat and fur products.
(d) Suggest and explain a possible way to protect rabbits from this potentiallyfatal disease.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
______________________________________________________________ [2]
*40ABY1132*
*40ABY1132*
11581
Section B
Quality of written communication is assessed in this section.
9 The interactions of some populations are shown in graphs A, B and C.
Graphs A and B summarise the results of two separate investigations into the growth of populations of four different species, 1, 2, 3 and 4.
A
species 2
Time/arbitrary units
Num
ber o
f org
anis
ms
living separately
species 1
living together
B
Time/arbitrary units
Num
ber o
f org
anis
ms
species 3species 4
living separately
living together
(a) Identify the population interactions shown in graph A and graph B. Explainreasons for your choices. [9]
*40ABY1133*
*40ABY1133*
11581[Turn over
Graph C shows a predator–prey interaction.
C
0 0
10 500
20 1000
30 1500
40 2000
50 2500
60 3000
70 3500
Wol
f num
bers
Moo
se n
umbe
rs
19601950 1970 1980 1990 2000Year
WolfMoose
(b) Comment on the predator–prey interaction shown and contrast this type ofinteraction with grazing and with parasitism. [9]
__________________________
(a) Identify the population interactions shown in graph A and graph B. Explainreasons for your choices.
Graph A _________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
© Wolves & Moose of Isle Royale
*40ABY1134*
*40ABY1134*
11581
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Graph B _________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
*40ABY1135*
*40ABY1135*
11581[Turn over
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
*40ABY1136*
*40ABY1136*
11581
(b) Comment on the predator–prey interaction shown and contrast this type ofinteraction with grazing and with parasitism.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
*40ABY1137*
*40ABY1137*
11581
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
*40ABY1138*
*40ABY1138*
11581
THIS IS THE END OF THE QUESTION PAPER
BLANK PAGE
DO NOT WRITE ON THIS PAGE
*40ABY1139*
*40ABY1139*
11581
BLANK PAGE
DO NOT WRITE ON THIS PAGE
Permission to reproduce all copyright material has been applied for.In some cases, efforts to contact copyright holders may have been unsuccessful and CCEAwill be happy to rectify any omissions of acknowledgement in future if notified.
Examiner Number
For Examiner’suse only
QuestionNumber Marks
1 2 3 4 5 6 7 8 9
TotalMarks
11581/4
*40ABY1140*
*40ABY1140*
DO NOT WRITE ON THIS PAGE