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GCSE
BIOLOGY
Higher Tier Paper 2H
H
Friday 7 June 2019 Afternoon Time allowed: 1 hour 45 minutes

Materials For Examiner’s Use

For this paper you must have:
• a ruler Question Mark
• a scientific calculator. 1
2
Instructions
3
• Use black ink or black ball-point pen.
• Fill in the boxes at the top of this page. 4
• Answer all questions in the spaces provided. 5
• Do all rough work in this book. Cross through any work you do not want to
6
be marked.
• In all calculations, show clearly how you work out your answer. 7
8
Information
• The maximum mark for this paper is 100. TOTAL
• The marks for questions are shown in brackets.
• You are expected to use a calculator where appropriate.
• You are reminded of the need for good English and clear presentation
in your answers.

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IIGS
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Answer all questions in the spaces provided. box

0 1 Figure 1 shows a food chain in a pond.

Figure 1

0 1 . 1 Which term describes the Daphnia in this food chain?

[1 mark]
Tick ( ) one box.

Apex predator

Primary consumer

Producer sumer

Secondary consumer

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0 1 . 2 Draw a pyramid of biomass for the food chain. box

material derived
Label each trophic level. biological from living or
recently
living organisms
→ group of organisms within an ecosystem which
[2 marks]

occupy level the

the same in
food chain

- Dragonfly niymph
① ② ③
④ - hydra
-
Daphnia
-
Tiers = number
of different
organisms (on
different levels)
I
Bottom middle tier > tier Etc) algae
-

tier >
top

0 1 . 3 Give one reason why the total biomass of the Daphnia in the pond is different from
the total biomass of the algae.
[1 mark]

Not all absorbed -

Non -

digestible parts lost in

faeces

_sS_"
" " ""

Algae not all eaten -

Used in
respiration / lost as coz

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Students investigated the size of the population of Daphnia in the pond. box

This is the method used.

1. Collect 1 dm3 of pond water from near the edge of the pond.

2. Pour the water through a fine net.

3. Count the number of Daphnia caught in the net.

4. Repeat steps 1–3 four more times.

Table 1 shows the results.

Table 1

Number of Daphnia
Sample number
in 1 dm3 water
1 5
2 21
3 0
4 16
5 28

0 1 . 4 Calculate the mean number of Daphnia in 1 m3 of pond water.

Ty sum
of values
1 m3 = 1000 dm3
no -

of values [2 marks]

5+2112,0+16+282
1
=

no .

daphnia in

>
1dm water

14 ✗ 1000=14000

Mean number of Daphnia in 1 m3 of pond water = 14000

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0 1 . 5 The pond was a rectangular shape, measuring: box

• length = 2.5 metres

• width = 1.5 metres

• depth = 0.5 metres.

I
, Calculate the estimated number of Daphnia in the pond.

Use your answer from Question 01.4.

Give your answer in standard form.

BY
[4 marks]

_•---e___# agog

Number of Daphnia in the pond =

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Rainfall can cause fertiliser to be washed from farmland into a pond. box

The students investigated the effect of fertiliser on the population of Daphnia in water
from the pond.

• The students put 20 Daphnia in each of five different concentrations of fertiliser.

• The students counted the total number of Daphnia in each concentration of fertiliser
after 2 weeks.

Figure 2 shows the results.

Figure 2

decreased
Daphnia
population

0 1 . 6 A concentration of 5.0 mg/dm3 of fertiliser caused a large increase in the population

of Daphnia.

Explain why.
[2 marks]

Increased Fourth of algae ,

so more Food for Daphnia

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0 1 . 7 acetate
Figure 1 is repeated below. box

Figure 1

feeds feeds feeds

µ
The population of Hydra will decrease when 20 mg/dm3 of fertiliser is added to
the pond.

Explain why.

µ
Hydra have less food because there are [2 marks]
" "" """ "

14

BIG Turn over for the next question

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0 2 Genetic material is made of DNA. box

0 2 . 1 Which structures in the nucleus of a human cell contain DNA?

[1 mark]

chromosomes

___f-
Figure 3 shows part of one strand of a DNA molecule.

Figure 3

_€BBEi .

z÷÷g÷ggggg÷÷
:

←fF&
""

nucleotide cytosine

0 2 . 2 Label parts X, Y and Z on Figure 3.

[3 marks]
Choose answers from the box.

Base Fatty acid Nucleotide Sugar Glycerol

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0 2 . 3 A complete DNA molecule is made of two strands twisted around each other. box

What scientific term describes this structure?

[1 mark]
Rod
ooble helix

] 1-

ii.
1 acid = 3 bases
amino
-

0 2 . 4 DNA codes for the production of proteins.

A protein molecule is a long chain of amino acids. -

How many amino acids could be coded for by the piece of DNA shown in Figure 3?
[1 mark]
Tick ( ) one box.

2 3 ✓ 9 18

0 2 . 5 Scientists have now studied the whole human genome.

Give two benefits of understanding the human genome.

[2 marks]

1 diagnosis of genetic disorders -

Understanding evolution /

ancestry / ethnic origins

2 treatment for inherited disorders -

Tracing human migration

patterns 8

_--_
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0 3 Phototropism is a growth response by part of a plant to light. box

0 3 . 1 Name one other tropism.

Give the stimulus the plant responds to in the tropism you have named.
[2 marks]

Tropism
geotropism hydrotropism thermotropism

Stimulus water
gravity heat

0 3 . 2 Plan an investigation to show the effect of light from one direction on the growth of
plant seedlings.

Include details of any controls needed.

You may use some of the equipment shown in Figure 4 and any other laboratory
apparatus.
[6 marks]

Figure 4

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box

*""÷÷÷:÷÷÷÷:÷!
, i m i n µ q
-

valid outcome ✓
given the same amount
of
water and the same
--

and soil
→ in a temperature type -

÷÷:÷÷÷:
logical order
-
there is
light all around

shining through
mean .eu,
, n.ign.a.me .

the experiment by straightening them out against

and measure
again after three days Tsing the same

method
✓

µ
Calculate the height increase each
for
-

mean

group

bendingandcomparewiththedi-tiono.io#-&
•
IIe

0 3 . 3 Explain how phototropism in a plant shoot helps the plant to survive.

[3 marks]

photosynthesis
✓
Plant leaves receive more
light so more occurs and the
-

plant produces more gÑcose

( starch material
/ carbohydrate / organic

11

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0 4 The human eye can focus on objects at different distances. box

Figure 5 shows how a clear image of a distant object is formed in a person’s eye.

Figure 5

Man
0 4 . 1
ciliary""
Explain how the person’s eye could adjust to form a clear image of a nearer object.
[6 marks]

/
M"
focus
retina
on
-

Ciliary muscles contract ,

so
they have a smaller Iliameter

0 looser
or
and
suspensory ligaments

✗ -
Lens therefore thickens and becomes more
rounded
suspensory -
The lens is
moreconverge.nl#
ligaments bends
light rays
inwards more

✓
retina
Image is thus
focused the
-

on

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box

0 4 . 2 Explain why a long-sighted person has difficulty seeing near objects clearly.
[2 marks]

Eye ball is too short / lens ÉtÉd enough . . .

. .
.
So
light focuses behind the retina

ciliary muscles

too weak

Lens not
sufficiently
elastic

0 4 . 3 Long-sightedness can be corrected by wearing spectacles.

Describe how spectacle lenses can correct long-sightedness.

[3 marks]

-
Convex 't converging lens DX concave
convex

is used to
refract Tight rays

inwards more

This
focuses the light rays
onto the retinal

11

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0 5 Table 2 gives the classification of four plant species. box

Table 2

Group Species 1 Species 2 Species 3 Species 4

✓ ✓
Kingdom Plantae Plantae ✓
Plantae Plantae -

e ✓
Phylum Spermatophyta r
Spermatophyta Spermatophyta
-
Spermatophyta
✓
Class Monocotyledonae Dicotyledonae ✗ Monocotyledonae✓ Dicotyledonae ✗

Order Poales ✓ Fabales ✗ Poales ✓

Scrophulariales ✗

Family Cyperaceae Fabaceae Poaceae Scrophulariaceae

Genus Eriophorum Pisum Poa Antirrhinum
Species angustifolium sativum annua majus

0 5 . 1 Species 1 and 3 are the most closely related.

What information in Table 2 gives evidence for this?

[1 mark]

species 1 and 3 have the same

Kingdom , phylum ,
class

and order

Figure 6 shows the inheritance of flower colour in two species of plant.

Figure 6

• In pea plants and in snapdragon plants, flower colour is controlled by one pair
of alleles. → version of a gene
nÑame
a

• In Figure 6 the parental generation plants are homozygous for flower colour.
Will always be
• In heterozygous pea plants, the allele for red flower colour is -
dominant.→
expressed if
#
• In heterozygous snapdragon plants, the alleles for flower colour are both present
one
dominant , expressed.
recessive
one

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Use the following symbols for alleles in your answers to Questions 05.2 to 05.4: box

Pea plants Snapdragon plants

both
Dominant R = allele for red flowers
Recessive -3
r = allele for white flowers -[CR = allele for red flowers
expressed CW = allele for white flowers

0 5 . 2 What is the genotype of the red-flowered pea plants in the F1 generation?

[1 mark]

Rr

0 5 . 3 What is the genotype of a white-flowered snapdragon plant?

[1 mark]

0 5 . 4
v÷÷÷÷÷÷
A gardener crossed two pink-flowered snapdragon plants.

Draw a Punnett square diagram to show why only some of the next generation plants
red and homozygous
white

had pink flowers. observable characteristics colour)

i.e ( .

Identify the phenotypes of all the offspring plants.

- [3 marks]
✓
÷

11
. 25 !
""
Cwcw
'
14 25%
White -_
=

CWCR 44 50%
Pink :
=

•
: not all pink

2/4 =
É 1-2×100=50 %
, 2-

-
3 4

0 5 . 5 What percentage of the offspring would you expect to have pink flowers?
[1 mark]

Percentage = 50 %

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Commercially, hundreds of pink-flowered snapdragon plants can be produced from box
one pink-flowered plant.

Figure 7 shows a tissue culture technique used for producing many plants from
one plant.

Figure 7

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._@sotnatmansfTffÉ②
outside the
0 5 . 6 gyps
Give a reason for each of the following steps shown in Figure 7. box
-00
[5 marks]

"|
•÷¥µ
Mt
Several groups
plants of cells be
are produced
can scraped off the leaf:

-
"" "
* " """ "

-fµ
protein For
providing

f-
energy
-

Nutrients are added to the agar

For jelly:
respiration
-

* snoots

⑧⑥µ⑧⑧
•

-
Hormones are added to the agar jelly: to
prevent the entry/
f-
growth og microorganisms
prevents decay / disease -
optimum for growth -
The plant cells are kept in sterile conditions:optimum for enzyme

=←__

The plant cells are kept at 20 oC:

0 5 . 7 Explain why the method shown in Figure 7 produces only pink-flowered plants.
[2 marks]

All the new

plants were
produced by aÉÉ?eproduction_ ,

genetically
identical
so all are

clones

All are crew

All have the same
genes / DNA
14

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0 6 Water conservation is important to the human body. box

mmmm
0 6 . 1 Which gland releases the hormone that controls water loss from the body?

Tick ( ) one box.

[1 mark]

Adrenal ✗ adrenaline

Pancreas ✗ digestion

Pituitary ✓ ADH

Thyroid ✗ thyroxine

0 6 . 2 Which hormone helps the kidneys to control water loss from the body?
[1 mark]
Tick ( ) one box.

ADH
✓

Adrenaline ✗ energy etc .

LH ✗ reproductive cycle

Thyroxine ✗ metabolism

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0 6 . 3 A man is walking across a desert. box

The man has used up his supply of drinking water.

ooo
Explain how the gland you named in Question 06.1 and the kidneys reduce
water
-0g loss.
[3 marks]

Higher concentration of blood (because less water in blood

causes Thore ADH to be released

ADH causes increased permeability of kidney . tubules to

water . .
.

/
increased water reabsorption
-

. - .
so

Question 6 continues on the next page

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0 6 . 4 Some people have kidney failure. box

Doctors may treat patients with kidney failure by either:

• dialysis

• a kidney transplant.

Explain two biological reasons why most doctors think that a kidney transplant is a
better method of treatment than dialysis.

Do not refer to cost or convenience.

[4 marks]

Reason 1 changes in concentrations / levels of substances / Urea

minimised less to
are
,
so chance of causing damage body
osmotic stress
cells
urea poisoning

Reason 2 blood not in contact with dialysis machine ,

so less

chance of bloodinfection_
blood clots need anti
clotting
→ no
for
-

medication
9

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0 7 Ragwort is a weed that grows on farmland. -
Valid outcome box

Logically sequenced
-

Ragwort is poisonous to horses.

0 7 . 1 Plan an investigation to estimate the size of a population of ragwort growing in a

rectangular field on a farm.
square frame
/
// [4 marks]

Use a 1m ✗ Im quadrat
/
Place computer /
quadrants randomly with use
of random
-

/
calculator generated coordinates Throw with closed
eyes etc
-
Throw / place at least 10 times and count
/
plant number within

quadrat each time . Calculate the mean Tnumber of plants per

me

/
find
of field
-

area

Population field
-
-

=
mean no .

plants / m2 ✗ area
of

--I--_
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The herbicide glyphosate will kill ragwort and other weeds. box

Scientists use bacteria for the genetic engineering of crop plants to make the crops
resistant to glyphosate.

Figure 8 shows the growth of a culture of the bacteria in a solution of nutrients

at 25 °C
µ

Figure 8

draw

§
rate ,
To find Rate 12h
!I÷
=

that
a
tangent point us -

REte-thegracdo.int#l&ffG--y5gS--- 3.437

,¥-
.

Rate =
gradient = -

*
= 3.4
-
0

Rate 7h =

-
0

+ =
= 10.00

I 10.0
+0

5 '
if I

0 7 . 2 Why did the rate of reproduction increase between 2 hours and 7 hours?
[1 mark]

More bacteria at this time so more divisions / reproduction per

unit time

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0 7 . 3 After 12 hours, the rate of reproduction decreased. box

Suggest three ways the scientists could maintain a high rate of reproduction in the
bacterial culture.
[3 marks]

1 add Increase temperature

more
sugar
-

2 add acids Remove toxins / waste

more amino / protein -

3 add more
oxygen
-
Maintain pH
-
Stir the culture

0 7 . 4 The rate of reproduction of the bacteria is fastest at 7 hours.

How many times faster is the rate of reproduction at 7 hours than the rate at
12 hours?
[4 marks]

① Tangent ✓
Rate 12h =
3,4

Rate 7h = 10.0 ✓

Rate 7h
scale 219411
=

factor
=
= . . .

I 2.9

between 2.9 and 3.4

g.
✓
Rate at 7 hours is 2. 9 times faster.

Question 7 continues on the next page

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0 7 . 5 Scientists transferred a gene for resistance to the herbicide glyphosate into box
the bacteria.

The genetically-modified (GM) bacteria can then transfer the glyphosate-resistance

gene to a crop plant.

Explain the advantage of making crop plants resistant to glyphosate.

[3 marks]
✓
to kill the weeds but not the
-
Causes the
glyphosate crop
/
nutrients (etc
Less competition for light water
-

,
. . .

/
so have
higher yield
-

crops
. - .

15

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0 8 It is important to keep the blood glucose concentration within narrow limits. box

0 8 . 1 A person eats a meal containing a lot of carbohydrate. This causes an increase in the
person’s blood glucose concentration.

Explain how the hormones insulin and glucagon control the person’s blood glucose
concentration after the meal.
[5 marks]

Blood causing insulin

glucose increases after meal secretion
-

Insulin cells / liver/ muscles

causes
glucose to enter
-

Insulin causes
glucose to be converted to glycogen
-

. . .

. . . So blood glucose decreases, causing glucagon secretion

Glucagon causes
glycogen to be converted to
glucose
-

0 8 . 2 The body cells of a person with Type 2 diabetes do not respond to insulin.

A person with Type 2 diabetes often has a higher blood insulin concentration than a
non-diabetic person.

Explain why.
[3 marks]

absor6lessgluc
-
Cells / liver / muscles ✓

-
-

Glucose concentration in blood remains

high
-

High
blood
glucose stimulates
Has
to release morein-u.nl

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Metformin is a drug used for treating people who have Type 2 diabetes. box

Scientists investigated the effects of metformin and two other drugs, A and B.

The scientists wanted to see how the drugs affected the blood glucose concentrations
of 220 people with Type 2 diabetes.

This is the method used.

1. Put the 220 people into five groups.

2. Treat each group with a different drug or combination of drugs for several weeks.

3. Give each person a meal high in carbohydrate.

4. Measure the blood glucose concentration of each person 30 minutes after the
meal and again 3 hours after the meal.

Maan
0 8 . 3 Suggest three variables that the scientists should have controlled in the investigation.
[3 marks]

1
age severity of diabetes
-

Dose of drug
-

2 height and blood concentration

mass
starting glucose
-

Other health condition

3
proportion of males
to
females

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The scientists recorded their results as a mean value for each group. box

The scientists calculated the ‘standard deviation’ for each group’s result.

Standard deviation is a measure of the spread of the individual results

above or below (±) the mean value.

The scientists gave each group’s result as:

mean ± standard deviation

The larger the standard deviation, the greater is the spread of results around
the mean.

0 8 . 4 Which of the results is the most precise?

Precision : how [1 mark]
close together
Tick ( ) one box. the values are

t
Mean = 171.6 ± 16.3 smallest S .
D

Mean = 177.2 ± 15.4

-
r

Mean = 182.5 ± 18.2

Mean = 205.2 ± 19.4

-3--6
Question 8 continues on the next page

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Table 3 and Figure 9 show the scientists’ results. box

Table 3

Metformin Metformin
Drugs used Metformin A B
+A +B
not
troops

ery large Number of people 60 40 25 65 30

Groups of
different
sizes Mean blood glucose
concentration
177.2 182.5 171.6
I 205.2 206.5
30 minutes after the
± 15.4 ± 18.2 ± 16.3 ± 19.4 ± 19.6
meal in mg/100 cm3
± standard deviation

Figure 9

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0 8 . 5 In Table 3 and Figure 9 some standard deviations of results overlap. box

• An overlap of standard deviations shows the difference between the means

is not significant.
• No overlap of standard deviations shows a significant difference between
the means.

A student looked at the scientists’ method and the results in Table 3 and Figure 9.

The student stated:

‘Metformin works better when used with other drugs.’

Evaluate the student’s statement.

[6 marks]

1%-1
µ .

•É→É¥
:-.
END OF QUESTIONS
.
18

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