1
In tulip plants, the petals can have markings called flecks.
There are two alleles for flecks in tulip plants: with flecks F; and without flecks f.
(a) Explain the meaning of the term dominant allele.
...................................................................................................................................................
............................................................................................................................................. [1]
(b) A tulip grower crosses two tulip plants.
He finds that 76 of the offspring have petals with flecks and 23 of the offspring have petals
without flecks.
(i)
Complete the genetic diagram to explain this result.
parental genotypes
…………………
X
…………………
parental phenotypes
…………………
X
…………………
gametes
....
....
X
....
....
offspring genotypes
……………………………
……………………………
offspring phenotypes
petals with flecks present
petals without flecks
[5]
(ii)
The tulip grower wants to produce a pure-breeding variety of tulips with petals without
flecks.
State the genotypes of the parent plants he should use to produce tulip plants without
flecks. Explain your answer.
parental genotypes
…………………
X
…………………
explanation ........................................................................................................................
...........................................................................................................................................
..................................................................................................................................... [2]
[Total: 8]
PhysicsAndMathsTutor.com
2
(a) Sickle cell anaemia is an inherited disease. The gene for haemoglobin exists in two forms,
HbN and HbS. People who are HbSHbS have the disease and experience symptoms including
fatigue and extreme pain in their joints. People who are HbNHbS are carriers of the disease
and may have mild symptoms, if any at all.
(i)
Table 2.1 shows four genetic terms.
Complete Table 2.1 by stating a specific example, used in the paragraph above, of each
genetic term.
Table 2.1
genetic term
example used in the passage
an allele
a heterozygous
genotype
a homozygous
genotype
phenotype
[4]
(ii)
Sickle cell anaemia is not found throughout the whole world. Most cases of the disease
occur in sub-Saharan Africa and in parts of Asia. The distribution is similar to that for the
infectious disease malaria.
Explain why the distribution of sickle cell anaemia and malaria are similar.
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[5]
PhysicsAndMathsTutor.com
(b) Down’s syndrome is an example of a characteristic that shows discontinuous variation.
State the cause of Down’s syndrome.
...................................................................................................................................................
...............................................................................................................................................[1]
(c) Explain how discontinuous variation differs from continuous variation, in its expression and
cause.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...............................................................................................................................................[3]
[Total: 13]
PhysicsAndMathsTutor.com
3
(a) Sickle cell anaemia is a genetic disorder that is found among people in certain parts of
the world.
A sample of blood was taken from a person with sickle cell anaemia and examined with
an electron microscope.
Fig. 4.1 shows some of the red blood cells in the sample.
Fig. 4.1
Explain the problems that may occur as these cells circulate in the blood system.
[4]
PhysicsAndMathsTutor.com
(b) The gene for haemoglobin exists in two alternative forms:
HA
HS
codes for the normal form of haemoglobin;
codes for the abnormal form of haemoglobin.
(i) State the name for the alternative forms of a gene.
[1]
(ii) A child has sickle cell anaemia. The parents do not have this disorder.
Complete the genetic diagram to show how the child inherited the disorder.
Use the symbols HA and HS in your answer.
parental phenotypes
normal
×
normal
parental genotypes
HAHS
×
HAHS
+
gametes
child’s genotype
...................
child’s phenotype
sickle cell anaemia
[2]
(iii) The parents are about to have another child.
What is the probability that this child will have sickle cell anaemia?
[1]
PhysicsAndMathsTutor.com
(c) The maps in Fig. 4.2 show the distribution of sickle cell anaemia and malaria in some
parts of the world.
distribution
of malaria
Indonesia and
the Philippines
key
malaria
distribution
of sickle cell
anaemia
key
sickle cell
anaemia
Fig. 4.2
PhysicsAndMathsTutor.com
northern
Australia
(i) Explain why sickle cell anaemia is common in people who live in areas where
malaria occurs.
[4]
(ii) Suggest why sickle cell anaemia is very rare among people who live in Indonesia
and northern Australia.
[2]
[Total: 14]
PhysicsAndMathsTutor.com
4
(a) The production of human gametes involves the type of nuclear division known as
meiosis.
State two reasons why meiosis is suitable for gamete production.
1
2
[2]
(b) The sex of a human fetus is determined by the sex chromosomes, X and Y.
Fig. 5.1 shows the determination of sex in four different examples.
Examples 3 and 4 show sex determination in twins.
example
gametes
zygote
cell from a fetus
1
X
+
X
XX
XX
2
X
+
Y
XY
XY
XX
3
X
+
X
XX
XX
X
+
X
XX
XX
X
+
X
XX
XX
4
Fig. 5.1
PhysicsAndMathsTutor.com
(i) Use 5.1 to explain how the sex of a fetus is determined.
[2]
(ii) Examples 3 and 4 show two ways in which twins are formed.
The twins in example 3 are identical.
Use Fig. 5.1 to explain why.
[2]
(c) During the development of a fetus, different genes are expressed at different times.
Explain what is meant by the term development.
[2]
PhysicsAndMathsTutor.com
(d) One of the genes that controls the ability of blood to clot is found only on the X
chromosome.
XH represents an X chromosome with the dominant allele for normal blood clotting.
Xh represents an X chromosome with the recessive allele which causes the blood to
clot slowly.
The Y chromosome is small and does not have the gene for blood clotting.
Here is a list of four genotypes.
XHXH,
XHXh,
XHY,
XhY
Choose the genotype from the list that matches each of the following:
●
gives a phenotype of long clotting time;
●
is heterozygous;
●
is homozygous.
[3]
(e) Haemophilia is a rare genetic condition in which the blood clots very slowly.
In the USA, haemophilia affects 1 in 5000 male births each year. In some cases these
births occur in families where the condition has not occurred before.
Explain how boys can have haemophilia when the condition has not previously existed
in their family.
[2]
[Total: 13]
PhysicsAndMathsTutor.com
1
The four o’clock plant, Mirabilis jalapa, can have flowers of three different colours as shown
in Fig. 4.1.
yellow
flower
crimson flower
orange-red flower
Fig. 4.1
(a) A student crossed some crimson-flowered plants with some yellow-flowered plants
(cross 1). She collected the seeds and grew them. All of the plants that grew from
these seeds had orange-red flowers.
Complete the genetic diagram to explain the result of cross 1.
parental phenotypes
crimson flowers
×
yellow flowers
parental genotypes
A CA C
×
AYAY
..............
+
..............
gametes
offspring genotype
................
offspring phenotype
........................
[3]
PhysicsAndMathsTutor.com
(b) The student then carried out three further crosses as shown in Table 4.1.
Table 4.1
cross
ross
2
offspring of cross 1 × offspring of cross
3
offspring of cross 1 × crimson-flowered plant
4
offspring of cross 1 × yellow-flowered plant
geno
of offspring
Complete Table 4.1 by writing the genotypes of the offspring of crosses 2, 3 and 4,
using the same symbols as in the genetic diagram in (a).
Write the genotypes in Table 4.1.
You may use the space below for any working.
[3]
(c) Flower colour in M. jalapa is not an example of the inheritance of dominant and
recessive alleles.
Explain how the results of the crosses show that these alleles for flower colour are not
dominant or recessive.
[3]
PhysicsAndMathsTutor.com
Flowers from M. jalapa were cross-pollinated.
(d) Explain the difference between self-pollination and cross-pollination.
[2]
(e) Some species of plants are self-pollinated.
Discuss the long-term effects of self-pollination on the evolution of these plants.
[4]
[Total: 15]
PhysicsAndMathsTutor.com
2
Haemoglobin is a large protein molecule. The structure of each haemoglobin molecule is
controlled by a gene that has two alleles:
•
HbA codes for the normal form of haemoglobin,
•
HbS codes for an abnormal form of haemoglobin.
Red blood cells containing only the abnormal form of haemoglobin become a stiff, sickle
shape in conditions of low oxygen concentration. This gives rise to sickle cell anaemia.
(a) Describe the harmful effects on the body of having red blood cells which become
sickle-shaped.
[5]
PhysicsAndMathsTutor.com
People who are heterozygous for the gene for haemoglobin produce both the normal and
abnormal forms of haemoglobin. These people show no symptoms or have very mild
symptoms known as sickle cell trait.
(b) (i) Complete the genetic diagram to show how a couple who are both heterozygous
may have a child with sickle cell anaemia.
parental phenotypes
sickle cell trait
×
sickle cell trait
parental genotypes
................
×
................
gametes
..............
..............
offspring genotypes
................ ................
offspring phenotypes ........................ ........................
+
..............
..............
................ ................
........................ ........................
[3]
(ii) What is the chance of a child born to this couple having sickle cell anaemia?
[1]
In some parts of the world, up to 25% of the population have sickle cell trait.
(c) State the advantage of having sickle cell trait.
[1]
PhysicsAndMathsTutor.com
(d) Discuss whether sickle cell trait is an example of codominance.
[2]
[Total: 12]
PhysicsAndMathsTutor.com
3
Two species of beetle, Tribolium castaneum and T. confusum, can infest and eat stored
flour.
In an investigation these two species were kept together in containers of flour under
different environmental conditions.
Many identical containers were set up, each with the same mass of flour.
Equal numbers of male and female flour beetles of the two species were put into each
container at the start.
The numbers of beetles were counted regularly.
The containers were left until only one species survived.
Table 5.1 shows the percentage of containers in which T. castaneum or T. confusum were
the only survivors.
Table 5.1
environmental conditions
percentage of containers in percentage of containers in
which only T. confusum
which only T. castaneum
survived / %
survived / %
A hot and wet
100
0
B hot and dry
10
90
C warm and wet
86
14
D warm and dry
13
87
E cold and wet
29
71
F cold and dry
0
100
(a) Compare the survival of the two species of flour beetle in different temperatures and
humidities.
Use data from Table 5.1 to illustrate your answer.
[4]
PhysicsAndMathsTutor.com
(b) Suggest why only one species survived in each container.
[2]
There is a gene in T. confusum which controls body colour.
A represents the dominant allele for red-brown body colour.
a represents the recessive allele for black body colour.
(c) Complete the genetic diagram below to show the colour of beetles produced when
heterozygous beetles are crossed with beetles that are homozygous recessive for this
gene.
parental phenotypes
............................
×
............................
parental genotypes
............................
×
............................
gametes
............. .............
+
............. .............
offspring genotypes
........................................................
offspring phenotypes
........................................................
ratio of phenotypes
........................................................
[4]
PhysicsAndMathsTutor.com
The eyes of Tribolium species are usually black. A very small number of flour beetles have
white eyes.
(d) Explain how this happens and why they are so rare.
[2]
(e) Insect pests, such as flour beetles, eat the flour and deposit nitrogenous waste in urine
and faeces into the flour. This leads to the growth of bacteria and fungi in the flour.
Suggest and explain what happens to the nitrogenous waste and the faeces released
by the flour beetles.
[4]
[Total: 16]
PhysicsAndMathsTutor.com
1
Fig. 2.1 shows the root systems of two species of desert plant, A and B.
A
B
soil level
20 m
Fig. 2.1
PhysicsAndMathsTutor.com
(a) Describe the two root systems shown in Fig. 2.1 and explain how each is an adaptation
for survival in a desert ecosystem.
[4]
(b) Describe and explain two ways in which the leaves of desert plants reduce water loss
in transpiration.
1.
2.
[4]
(c) Xylem and phloem are transport tissues in plants. They transport substances from
organs that are known as sources to organs known as sinks.
Complete the table to show:
•
•
•
two substances being transported in each tissue
an organ that is a source for substances being transported in each tissue
an organ that is a sink for substances being transported in each tissue.
tissue
substances being
transported
source of
substances in the
plant
sink for substances
in the plant
1 …………………
xylem
2 ………………….
1 …………………
phloem
2 ………………….
[6]
[Total: 14]
PhysicsAndMathsTutor.com
2
(a) Define the term self-pollination.
[2]
Snapdragon plants have flowers with three colours: red, pink and white.
Some students investigated the inheritance of flower colour in snapdragons.
In cross 1 they cross-pollinated plants that were homozygous for red flowers with plants
that were homozygous for white flowers. They collected and planted the seeds from
cross 1. All of the resulting plants had pink flowers.
In cross 2 they self-pollinated all the pink-flowered plants and found that in the next
generation there were red-flowered plants, white-flowered plants and pink-flowered plants.
(b) Complete the genetic diagrams to show how flower colour is inherited in snapdragon
plants.
Use the symbol IR for the allele for red flowers and IW for the allele for white flowers.
cross 1
parental phenotypes
red flowers
×
white flowers
parental genotypes
...........
×
...........
gametes
...........
...........
offspring
genotypes
...................
offspring
phenotypes
pink flowers
PhysicsAndMathsTutor.com
cross 2
parental phenotypes
pink flowers
×
pink flowers
parental genotypes
...........
×
...........
gametes
offspring
genotypes
...........
...........
………………………………………………………………………………………….
ratio of offspring
phenotypes ……………………………………………………………………………………… [4]
(c) Another student cross-pollinated pink-flowered plants with white-flowered plants.
Complete the genetic diagram to show the results that the student would expect.
phenotypes
pink flowers
×
white flowers
genotypes
...........
×
...........
gametes
offspring
genotypes
...........
...........
………………………………………………………………………………………….
ratio of offspring
phenotypes ……………………………………………………………………………………… [3]
PhysicsAndMathsTutor.com
(d) Explain the advantages of sexual reproduction to a species of flowering plant, such as
the snapdragon.
[4]
[Total: 13]
PhysicsAndMathsTutor.com
3
(a
Define the term gene.
[1]
The medical condition sickle cell anaemia is widely distributed in Africa, parts of Asia and
the Americas. People with sickle cell anaemia have red blood cells with an abnormal form
of haemoglobin.
The gene for haemoglobin exists in two forms:
HN = allele for normal haemoglobin
HS = allele for abnormal haemoglobin
(b) Complete the genetic diagram below to show how two people who are heterozygous
for this gene may have a child who has sickle cell anaemia.
Use the symbols HN and HS in your answer.
parental phenotypes
normal
x
normal
parental genotypes
………
x
……….
gametes
………
+
……….
child’s genotype
…………
child’s phenotype
sickle cell anaemia
[3]
(c) Describe the effects of sickle cell anaemia on the body.
[4]
PhysicsAndMathsTutor.com
(d) Fig. 5.1 is a map that shows the distribution of the allele for the abnormal form of
haemoglobin (HS) and malaria in Africa.
sickle cell allele
malaria
Fig. 5.1
Explain how natural selection is responsible for the distribution of the allele for the
abnormal form of haemoglobin (HS).
[5]
PhysicsAndMathsTutor.com
(e) Sickle cell anaemia is an example of the variation that exists in the human population.
It is a form of discontinuous variation.
Explain why sickle cell anaemia is a form of discontinuous variation.
[3]
[Total: 16]
PhysicsAndMathsTutor.com
4
Transpiration and translocation are processes responsible for transporting materials around
a plant.
(i) Complete the table by stating the materials moved by these processes, their sources
and their sinks.
process
materials moved
source of materials
in the plant
sink for materials in
the plant
1
transpiration
2
1
translocation
2
[6]
(ii) State two reasons why the source and sink for translocation in a plant may change at
different stages in the growth of a plant.
[2]
[Total: 8]
PhysicsAndMathsTutor.com
1
One variety of the moth, Biston betularia, has pale, speckled wings. A second variety of the
same species has black wings. There are no intermediate forms.
Equal numbers of both varieties were released into a wood made up of trees with pale bark.
Examples of these are shown in Fig. 5.1.
Fig. 5.1
After two weeks as many of the moths were caught as possible.
The results are shown in Table 5.1.
Table 5.1
wing colour of moth
number released
number caught
pale, speckled
100
82
black
lac
36
(a) (i) Suggest and explain one reason, related to the colour of the bark, for the
difference in numbers of the varieties of moth caught.
[1]
(ii) Suggest and explain how the results may have been different if the moths had
been released in a wood where the trees were blackened with carbon dust from air
pollution.
[2]
PhysicsAndMathsTutor.com
Table 5.2 shows the appearance and genetic make-up of the different varieties of this
species.
Table 5.2
wing colour
genetic make-up
pale, speckled
GG; Gg
black
la
(b) (i) State the appropriate genetic terms for the table headings.
wing colour
genetic make-up
[2]
(ii) State and explain which wing colour is dominant.
dominant wing colour
explanation
[2]
(c) State the type of genetic variation shown by these moths. Explain how this variation is
inherited.
[3]
PhysicsAndMathsTutor.com
(d) Heterozygous moths were interbred. Use a genetic diagram to predict the proportion of
black winged moths present in the next generation.
proportion of black winged moths =
[5]
(e) (i) Name the process that can give rise to different alleles for wing colour in a
population of moths.
[1]
(ii) Suggest one factor which might increase the rate of this process.
[1]
[Total: 17]
PhysicsAndMathsTutor.com
2
Fig. 1.1 shows seven lizards that are at risk of becoming extinct.
C
A
B
E
D
F
G
PhysicsAndMathsTutor.com
(a) (i)
Name the vertebrate group that contains lizards.
.......................................................................................................................................[1]
(ii)
Use the key to identify each species. Write the letter of each species (A to G) in the
correct box beside the key. One has been done for you.
key
1
2
3
4
5
6
(a) feet with three toes
go to 2
(b) feet with five toes
go to 3
(a) has a collar or crest on head
go to 4
(b) has no collar or crest on head
Chalcides minutus
(a) spikes along back
go to 5
(b) no spikes along back
go to 6
(a) ridges extend along back and tail
Brookesia perarmata
(b) no ridges along back or tail
Calumma parsonii
(a) blunt, rounded head
Amblyrhynchus cristatus
(b) elongated head
Cyclura lewisi
(a) large raised scales on skin
Abronia graminea
(b) scales on skin are not large or raised
Varanus komodoensis
D
[3]
(b) The effect of humans on the environment has caused the populations of the lizard species in
Fig. 1.1 to decrease.
Explain why conserving lizards is important.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...............................................................................................................................................[3]
PhysicsAndMathsTutor.com
(c) Zookeepers report that isolated female Komodo dragons, Varanus komodoensis, have
produced offspring asexually. This is very unusual in vertebrates.
(i)
State two disadvantages of asexual reproduction.
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]
(ii)
State two disadvantages of sexual reproduction.
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]
(d) Sexual reproduction requires meiosis to occur.
(i)
Define the term meiosis.
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]
(ii)
Explain the significance of meiosis to the survival of endangered species of lizards.
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[3]
[Total: 16]
PhysicsAndMathsTutor.com
3
(a) Fig. 4.1 shows a section through the anther of a lily flower. The cells in the centre are dividing
by meiosis.
Fig. 4.1
(i)
Name the product of meiosis that is formed in anthers.
.......................................................................................................................................[1]
(ii)
Explain the importance of meiosis in sexual reproduction.
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]
PhysicsAndMathsTutor.com
(b) Fig. 4.2 shows a flower of Lilium polyphyllum, a lily that grows in the Himalayan mountains.
This species is cross-pollinated by insects.
Fig. 4.2
(i)
Explain what is meant by cross-pollination.
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]
(ii)
Name one feature visible in Fig. 4.2 that helps to attract insects.
.......................................................................................................................................[1]
PhysicsAndMathsTutor.com
(c) Plants of this species that grow at low altitudes produce flowers 60 days before the plants of
the same species that grow at high altitudes.
(i)
Suggest one environmental reason why lilies that grow at lower altitudes flower earlier
than the lilies at higher altitudes.
.......................................................................................................................................[1]
(ii)
Explain why flowering time is an example of continuous variation.
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
...........................................................................................................................................
.......................................................................................................................................[2]
(d) Scientists think that plants of L. polyphyllum growing at high altitudes may evolve into a new
species.
Explain how natural selection could lead to the evolution of a new species of lily.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...............................................................................................................................................[5]
[Total: 14]
PhysicsAndMathsTutor.com
1
A healthy kidney controls the excretion of urea and other waste products of metabolism
from the blood.
After kidney failure there are two possible treatments: dialysis or a kidney transplant.
Fig. 4.1 shows how blood and dialysis fluid move through a dialysis machine.
A
blood
flow
dialysis fluid
B
bubble
trap
pump
blood
patient’s
arm
Fig. 4.1
(a) Describe the changes that occur to the blood as it flows through the dialysis machine
from A to B.
[2]
PhysicsAndMathsTutor.com
(b) Discuss the advantages of kidney transplants compared with dialysis.
[3]
PhysicsAndMathsTutor.com
(c) Two brothers have to make a difficult decision.
One brother, with blood group AB, has kidney failure and is on dialysis.
The healthy brother has agreed to donate one of his kidneys to his brother. He has to
have a blood test.
Their father has blood group A and their mother has blood group B.
The brothers have a sister who has blood group O.
(i) Explain how this girl has blood group O when her parents have different blood
groups. You must use the space below for a genetic diagram to help your answer.
Use the symbols IA, IB and IO to represent the alleles involved in the inheritance of
blood groups.
parental phenotypes
blood group A
×
blood group B
parental genotypes
...................
×
...................
................... ...................
+
................... ...................
gametes
girl’s genotype
...................
girl’s phenotype
...................
[4]
(ii) The healthy brother can only donate the kidney to his brother if they both have the
same blood group.
What is the probability that the healthy brother also has blood group AB?
[1]
[Total: 10]
PhysicsAndMathsTutor.com
2
Fig. 1.1 shows a vertical section through a flower of soybean, Glycine max, following
self-pollination. Fig. 1.2 shows part of the section at a higher magnification.
stigma
A
Fig. 1.1
A
B
C
Fig. 1.2
(a)
a)
Name the parts labelled A to C shown in Figs. 1.1 and 1.2.
A
B
C
PhysicsAndMathsTutor.com
[3]
(ii) Describe what happens to the structures shown in Figs. 1.1 and 1.2 to bring about
fertilisation. You may refer to the structures labelled A to C by their letters if you
wish.
[3]
(iii) Explain the advantages and disadvantages of self-pollination for flowering plants,
such as soybean.
advantages
disadvantages
[4]
(b) Soybean is a dicotyledonous plant.
(i) Name the genus to which the soybean belongs.
[1]
(ii) State two features which are only found in dicotyledonous plants.
1.
2.
[2]
[Total: 13]
PhysicsAndMathsTutor.com
3
Fig. 4.1 is a photograph of a root of radish covered in many root hairs.
Fig. 4.1
(a) Using the term water potential, explain how water is absorbed into root hairs from the
soil.
[3]
PhysicsAndMathsTutor.com
A potometer is a piece of apparatus that is used to measure water uptake by plants.
Most of the water taken up by plants replaces water lost in transpiration.
A student used a potometer to investigate the effect of wind speed on the rate of water
uptake by a leafy shoot. As the shoot absorbs water the air bubble moves upwards.
The student’s apparatus is shown in Fig. 4.2.
capillary tube
coloured water
air bubble
beaker of water
Fig. 4.2
PhysicsAndMathsTutor.com
The student used a fan with five different settings and measured the wind speed. The
results are shown in Table 4.1.
Table 4.1
wind speed /
metres per
second
distance travelled
by the air bubble
/ mm
time / minutes
rate of water
uptake / mm per
minute
0
4
10
0.4
2
12
5
2.4
4
20
5
4.0
6
35
5
7.0
8
40
2
…………
(b) Calculate the rate of water uptake at the highest wind speed and write your answer in
the table.
[1]
(c) Describe the effect of increasing wind speed on the rate of water uptake. You may
use figures from Table 4.1 to support your answer.
[2]
(d) State two environmental factors, other than wind speed, that the student should
keep constant during the investigation.
1.
2.
PhysicsAndMathsTutor.com
[2]
(e) Some of the water absorbed by the plants is not lost in transpiration.
State two other ways in which water is used.
1.
2.
[2]
(f) Water moves through the xylem to the tops of very tall trees, such as giant redwoods of
North America. The movement of water in the xylem is caused by transpiration.
Explain how transpiration is responsible for the movement of water in the xylem.
[4]
(g) Plants that live in hot, dry environments show adaptations for survival.
State three structural adaptations of these plants.
1.
2.
3.
[3]
[Total: 17]
PhysicsAndMathsTutor.com
4
(a
Four definitions of terms used in genetics are shown in Table 5.1.
Table 5.1
definitions
efini
the outward appearance of an organism
……………………..
a length of DNA that codes for a protein
……………………..
having one set of chromosomes
……………………..
type of nuclear division which gives
daughter nuclei that are genetically identical
…………………….
For each of the definitions, select an appropriate term from the list and write it in the
box provided.
chromosome
genotype
mitosis
diploid
haploid
mutation
dominant
heterozygous
phenotype
gene
homozygous
recessive
[4]
(b) A couple who have blood groups A and B have four children. Each child has a different
blood group.
Use the space below to draw a genetic diagram to show how this is possible. Use the
symbols, IA , IB and Io, for the alleles.
parental blood groups
parental genotypes
A
×
B
×
gamete genotypes
children’s genotypes
children’s blood groups
[4]
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(c) Explain what is meant by codominance. You may refer to the genetic diagram in (b) to
help you with your answer.
[3]
(d) Insulin produced by genetically engineered bacteria first became available in 1982.
Before 1982, insulin had been prepared from dead animal tissues.
Explain the advantages of using insulin produced by genetically engineered bacteria
rather than insulin from dead animal tissues.
[3]
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(e) Fig. 5.1 shows some of the steps involved in the genetic engineering of bacteria.
human cell
bacterium
chromosomes
in nucleus
R
S
T
geneticallyengineered
bacterium
reproduction
of bacteria
production of insulin
Fig. 5.1
(i) Name structure R and state what it is made from.
[2]
(ii) State what is added at stages S and T.
[1]
[Total: 17]
PhysicsAndMathsTutor.com