Download SEX and FERTILISATION

SEX and FERTILISATION
1.
2.
3.
In humans which of the following gametes are not normally
formed?
A
an egg with an X chromosome
B
an egg with a Y chromosome
C
a sperm with an X chromosome
D
a sperm with a Y chromosome
The DNA of a chromosome carries information which
determines the structure and function of
A
fats
B
bases
C
carbohydrates
D
proteins
In humans, which of the following gametes would determine a
male offspring at fertilisation?
A
an egg cell with an X chromosome
B
an egg cell with a Y chromosome
C
a sperm cell with an X chromosome
D
a sperm cell with a Y chromosome
1
4.
The table below gives information about chromosomes in some
human cells.
Which line in the table is correct?
Cell
5.
Number of
Number of
chromosome sets chromosomes
A
nerve
2
23
B
egg
1
23
C
lymphocyte
1
46
D
sperm
2
23
Which of the following is a correct description of a
chromosome?
A
a chain of DNA bases
B
a chain of RNA bases
C
a chain of amino acids
D
a chain of sugar molecules
2
6.
The diagram below represents the transmission of sex
determining chromosomes from parents to offspring.
Gametes
mother
father
P
R
Q
S
Which line in the table below correctly identifies the sex
chromosomes for the gametes P, Q, R and S?
Gamete
P
7.
Gamete Gamete Gamete
Q
R
S
A
XX
XX
XY
XY
B
X
X
X
Y
C
XX
XY
XX
XY
D
X
Y
X
Y
Which line in the table below names gametes and their sites of
production in a flowering plant?
Male
gamete
Site of
production
Female
gamete
Site of
production
A
sperm
testes
egg
ovule
B
pollen
nucleus
anther
egg cell
ovary
C
sperm
anther
egg
ovary
D
pollen
nucleus
testes
egg cell
ovule
3
8.
9.
In humans, all sperm contain
A
an X chromosome
B
a Y chromosome
C
an X and Y chromosome
D
either an X or a Y chromosome
The diagram below shows the main parts of a flower.
Which line in the table identifies X and the type of gamete it
produces?
Name of X
Type of gamete
produced
A
ovary
male
B
ovary
female
C
anther
female
D
anther
male
4
10.
(a)
The diagram below shows meiosis and fertilisation in
humans.
Cell A
(in testis)
from ovary
Meiosis
Cell B
Fertilisation
Cell D
(i)
(b)
Copy and complete the following table by naming
the cells and stating the number of chromosomes
present in each.
Cell
Name of cell
A
testis cell
B
sperm
Number of
chromosomes
C
23
D
46
(ii)
Describe what happens during fertilisation.
(i)
Name a structure in a cell which is composed of a
chain of DNA bases.
(ii)
Explain the importance of the order of the DNA
bases to the functioning of a cell.
5
11.
(a)
The diagram below shows all the chromosomes found in a
human skin cell.
Identify the sex of the person and give a reason for your
answer.
(b)
Copy the following sentences and underline one option in
each set of brackets to make the sentences correct.
During meiosis, matching chromosomes pair and separate
producing gametes
with one set
of
body cells
two sets
chromosomes. A zygote is produced from these cells by
random assortment
fertilisation
.
6
12.
(a)
Copy and complete the table below to give the site of
production and number of chromosomes of each type of
gamete.
Human
gamete
Site of production
Number of
chromosomes
egg
sperm
(b)
The diagram below shows the chromosome complement
of a cell about to divide to form gametes.
(i)
How many sets of chromosomes does this cell
contain?
(ii)
Name the type of cell division which produces
gametes.
(iii) The following diagram shows one way in which these
chromosomes may line up during cell division.
Copy and complete the diagram below to show one
other way in which the chromosomes may line up.
7
12. Contd.
(c)
Chromosome pairs line up in a variety of ways.
Explain why this random assortment is important.
8
13.
(a)
The diagram below shows a yeast cell.
(i)
Name the structure shown in the yeast cell which
contains the genetic information.
(ii)
A molecule consisting of chains of bases is contained
in chromosomes.
(A) Name this molecule.
(B) Explain how this molecule controls cell
activities.
(b)
Gamete production is essential to sexual reproduction.
(i)
Name the division of the nucleus that occurs during
gamete production.
(ii)
Name the process occurring during this division that
increases variation.
(iii) Copy the following sentences and underline one
option in each set of brackets to make the sentences
correct.
The number of chromosomes in gametes is
half
twice
the number found in body cells.
The zygote is formed by
half
twice
fusion
division
and contains
the number of chromosomes in a gamete.
9
14.
You may use a labelled diagram where appropriate.
Give an account of gamete formation in human females.
15.
Describe the structure of chromosomes.
Explain how chromosomes determine the characteristics
of an organism.
16.
The diagram below shows the two stages that result in the
formation of offspring in animals.
cell in testis
cell in ovary
Stage 1
Stage 2
offspring
(a)
Describe what happens at each stage.
(b)
Explain how variation is brought about during each stage.
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GENETICS and INHERITANCE
17.
A true breeding red bull is mated with a true breeding white
cow. The offspring are all intermediate in colour. (roan)
This type of inheritance is
18.
A
polygenic
B
recessive
C
co-dominant
D
dominant
In tomato plants the allele for red fruit is dominant to the allele
for yellow fruit.
If a heterozygous tomato plant is crossed with a plant which
produces yellow fruit, the expected phenotype ratio of the
offspring would be
A
3 red : 1 yellow
B
1 red : 3 yellow
C
1 red : 2 yellow
D
1 red : 1 yellow
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19.
Achoo syndrome is a dominant characteristic in humans which
causes the sufferer to sneeze in response to bright light.
A woman who is homozygous for the syndrome and a man is
unaffected have children.
What proportion of their children would be expected to have
Achoo syndrome?
20.
A
0%
B
25%
C
50%
D
100%
When a plant with red flowers was crossed with a plant with
white flowers, the F1 plants had pink flowers.
The F1 plants were then self-fertilised.
What ratio of flower colours would be found in the F2
generation?
A
1 red : 2 white
B
1 white : 2 pink
C
1 red : 2 pink : 1 white
D
1 red : 1 pink : 1 white
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Questions 21 and 22 refer to the information below.
In mice, the dominant form (B) of one gene determines black coat
colour; brown coat colour results from the recessive form (b) of the
gene.
A cross between two mice is shown below.
P
BB x
bb
F1 Bb
21.
22.
Which of the following shows all the possible genotypes of the
F2 generation?
A
BB and Bb
B
bb and Bb
C
BB and bb
D
BB, Bb and bb
What proportion of the F2 generation would be expected to
have black coats?
A
B
C
D
1
4
1
2
2
3
3
4
13
23.
24.
25.
If an inherited characteristic is controlled by alleles of more
than one green, then the type of inheritance is called
A
true bleeding
B
polygenic
C
co-dominant
D
monohybrid
Which term refers to a description of a characteristic of an
organism?
A
genotype
B
phenotype
C
allele
D
natural selection
Which term refers to forms of a gene controlling the same
characteristic?
A
genotypes
B
phenotypes
C
alleles
D
dominant
14
26.
In humans the length of the big toe is controlled by a single
gene which has two alleles.
A father is homozygous for short big toe. The mother has long
big toes. All of their children have short big toes.
(a)
Copy and complete the following sentences by
underlining the correct word in each pair, using the
information above.
Long
Short
big toe is the dominant form of this gene.
The mother is
homozygous
and the children are all
heterozygous
homozygous
heterozygous .
15
26. Contd.
(b)
The ability to roll the tongue is controlled by another gene
in humans. The allele for tongue rolling (R) is dominant to
the allele for non tongue rolling (r).
The diagram below shows the occurrence of this tongue
rolling gene.
Key
Female
Male
tongue roller
non tongue roller
mother father
Kate
Jill
Ben
Jamie
(i)
With respect to the tongue rolling gene, state Jamie’s
phenotype and Ben’s genotype.
(ii)
Kate has a son and his father is homozygous dominant
for the characteristic.
What is the percentage chance that the son is a tongue
roller?
(iii) State the two sex chromosomes present in Jill’s body
cells.
16
27.
(a) The table below shows the results of a study into the
phenotypes of two pairs of human adult identical twins.
Identical twins were used in this study as they have the
same genotype.
One pair of identical twins had been raised together since
birth.
The second pair had been separated since birth and raised
by different families.
Phenotype
Appearance of twins Appearance of twins
raised together
raised apart
P
Q
R
S
Eye colour
blue
blue
brown
brown
Height (cm)
175
174
180
176
Blood group
A
A
O
O
Hand span (cm)
23
23.5
25
23
From the results, copy and complete the following table by
using tick(s) to show whether each phenotype was affected
by genes, the environment or both.
Phenotype
Affected by genes Affected by environment
Eye colour
Height
Blood group
Hand span
(b) In another study into plant phenotypes, leaf lengths were
found to vary across a wide range.
What term is used to describe this type of variation?
17
28.
(a) In peas the height of the plant is controlled by one gene
which has two alleles.
T represents the dominant allele for tall stems.
t represents the allele for short stems.
True breeding, tall-stemmed pea plants were crossed with
short-stemmed pea plants to produce the F1 generation.
(i)
State the genotype of the parents.
(ii)
State the phenotypes of the F1 plants.
(iii) Plants from the F1 generation were crossed to produce
the F2 generation of plants.
State the phenotypes and their expected ratio in the F2
generation.
18
28. Contd.
(b) Seeds from true breeding, tall-stemmed pea plants were
provided with different growing conditions as shown in the
diagrams below.
(i)
Compare the expected appearance of the plants in
each group.
(ii)
What term is used to describe the effect of different
conditions on the phenotype of an organism?
19
29.
The diagram below shows the occurrence of tongue rolling in a
family.
(a) State the dominant form of the gene.
(b) Identify the individuals in the F1 generation.
(c) (i)
Use the information in the diagram to copy and
complete the table below.
Individual
Genotype
A
B
C
G
L
(ii)
Name an individual from the table who is
heterozygous for the gene.
20
30.
(a) Name the male gametes and their site of production in a
flower.
(b) Tomato plants were used in an experimental monohybrid
cross.
The parental phenotypes were cut leaf and potato leaf as
shown in the diagrams below.
cut leaf
potato leaf
The parent plants were both true breeding.
The F1 plants were self-pollinated.
The F2 generation contained 80 plants with the cut leaf
genotype and 20 plants with the potato leaf genotype.
(i)
Explain what is meant by the term true breeding.
(ii)
State which characteristic is dominant and give a
reason.
(iii) The results obtained in the F2 generation differ from
the expected results.
(iv) Suggest one reason why the results obtained differ
from the expected results.
21
31.
(a) In the fruitfly Drosophila melanogaster, the dominant
form (G) of one gene determines grey body colour; black
body colour results from the recessive form (g) of the gene.
The genotypes of the parent flies used in a cross are shown
below.
GG
gg
(i)
State the genotype(s) of the F1 offspring of this cross.
(ii)
Copy the table below and decide if each of the
following statements about this cross is True or False,
and tick () the appropriate box.
If the statement is False, write the correct word in the
Correction box to replace the word underlined in the
statement.
Statement
True False
The different
forms of the gene
are hybrids.
The parents in
this cross are true
breeding.
The F1 flies are
homozygous.
22
Correction
31. Contd.
(a) Contd.
(iii) Two flies from the F1 were allowed to breed together.
This produced 56 grey flies and 14 black flies in the
F 2.
Express this result as a simple whole number ratio.
(grey flies : black flies)
(iv) The expected ratio of grey flies to black flies in the F2
is 3:1. Suggest why the observed ratio was different
from the expected ratio.
(b) In a study of variation, a group of students collected
information on the heights and blood groups of a class.
For each variation state whether it is continuous or
discontinuous.
(c) Polygenic inheritance occurs as a result of the interaction of
several genes.
Give an example of polygenic inheritance in humans.
23
32.
In fowl, the dominant form (R) of one gene determines rose
comb shape; single comb shape results from the recessive form
(r) of the gene.
The diagram below shows the results of two crosses.
Cross 1 parents
True-breeding
rose comb fowl
Cross 1 offspring
True-breeding
single comb fowl
all rose comb fowl
Cross 2 parents Rose comb fowl from x
Cross 1 offspring
Single comb fowl
Cross 2 offspring
Single comb fowl
Ratio
(a) (i)
(ii)
Rose comb fowl
1
:
1
Which offspring contains only one phenotype?
Copy and complete the Punnet square below to show
the genotypes of the gametes of the Cross 2 single
comb parent and the genotypes of the offspring
produced.
Genotypes of gametes of
Cross 2 single comb parent
Genotypes of
R
gametes of
Cross 2 rose
comb parent r
24
32. Contd.
(b) Copy the table below and decide if each of the following
statements is True or False, and tick () the appropriate
box.
If the statement is False, write the correct word in the
Correction box to replace the word underlined in the
statement.
Statement
True False
A characteristic
controlled by many
genes is called
co-dominant.
The gene for comb
shape has two
different alleles.
True breeding is
another way of
describing a
homozygous
individual.
25
Correction
GENETIC ENGINEERING
33.
In 1997 the USA planted 8.2 million hectares of land with
genetically engineered crops. By 1998, this had increased to
20.5 million hectares.
What was the percentage increase in the area sown between
1997 and 1998?
34.
A
12.3%
B
66%
C
150%
D
166.7%
Genetic engineering can be used to alter bacterial cells in
order to produce human insulin.
The stages in the process are:
1.
insulin gene extracted from a human cell
2.
bacteria divide and produce large quantities of human
insulin
3.
plasmid is removed from bacterial cell and ‘cut’ open
4.
insulin gene is inserted into bacterial plasmid.
The correct sequence of these stages is
A
1, 3, 4, 2
B
1, 3, 2, 4
C
3, 4, 2, 1
D
3, 1, 2, 4
26
35.
The table below shows the relationship between planting
density and the mass of seed harvested for a trial cereal crop.
4
Mass of seed
harvested
(grams per
square metre)
60
8
86
16
104
32
77
128
22
Planting density
(number of plants
per square metre)
The reason a low mass of seed was harvested when the planting
density was 128 plants per square metre was
36.
A
less disease at high planting densities
B
more nutrients available
C
more competition for light and nutrients
D
less space for weeds
Which term refers to the process by which organisms that are
better adapted to their environment survive and breed?
A
Meiosis
B
Natural selection
C
Selective breeding
D
Genetic engineering
27
37.
The graph below shows the average number of peppered moths
in a woodland in June of each year over a 10 year period.
Studies have shown that an increase in the number of dark
moths is related to an increase in the level of pollution in the
atmosphere.
Which of the following best describes what would happen to the
number of moths if measures were introduced to reduce air
pollution from year 7?
A
Increase in dark moths and decrease in light moths
B
Decrease in dark moths and increase in light moths
C
Increase in dark moths and increase in light moths
D
Decrease in dark moths and decrease in light moths
28
38.
The table below shows the relationship between planting
density and the mass of seed harvested for a cereal crop trial.
4
Mass of seed
harvested
(grams per
square metre)
60
8
86
15
105
32
77
128
21
Planting density
(number of plants
per square metre)
What is the percentage increase in mass of seed harvested as
planting density increases from 4 to 14 plants per square metre?
A
45%
B
75%
C
90%
D
105%
29
39.
The diagram below shows the same sections of matching
chromosomes found in four fruit flies, A, C, C and D.
The genes shown on the chromosomes can be identified using
the following key.
Key
gene for striped body
gene for unstriped body
gene for normal antennae
gene for abnormal antennae
Which fly is homozygous for both genes?
30
40.
(a) Organisms vary from one generation to the next.
This variation may result from the following factors.
A
Natural selection
B
Selective breeding
C
Environmental impact
Copy the table below and use this information to complete
the table.
(Each letter may be used once, more than once or not at all)
Description
Factor
Produces changes not passed on to
future generations
Organisms that are better adapted to
their surroundings survive and breed
Effect of the surroundings on the final
appearance of offspring
Desirable characteristics chosen to
produce improved offspring
(b) Arrange the following stages of genetic engineering in the
correct order. The first stage has been given.
Stage number
1
2
3
4
5
Description of stage
Bacterial cell produces insulin
Insulin gene inserted into plasmid
Plasmid removed from bacterial cell
Plasmid inserted into bacterial cell
Insulin gene removed from human
chromosome
(c) Give one advantage of genetic engineering.
31
40. Contd.
(d) The desert plant shown below has adaptations to survive in
dry conditions.
Spines
Fleshy stem
Shallow widespread
root system
From the diagram give one adaptation which reduces water
loss.
32
41.
The diagram below shows a genetically engineered bacterial
cell.
gene from
another
organism
bacterial
chromosome
(a) Name the type of molecule found in a bacterial
chromosome.
(b) The bacterium was genetically engineered to produce a
particular substance.
Name one example of a substance which can be produced
in this way and describe its use.
(c) Genetic engineering can produce new genotypes to
provide better organisms for particular functions.
Give one advantage and one disadvantage of genetic
engineering compared with selective breeding.
33
42.
Labelled diagrams may be included where appropriate.
Genetic engineering uses bacteria to produce human
insulin. Describe the stages involved in this process.
43.
Describe the process of natural selection as illustrated by
the peppered moth Biston betularia.
44.
The diagram below shows the two different forms of the
peppered moth Biston betularia on the bark of a tree located in
an unpopulated area.
Name and describe the process by which the black form of the
moth became the most common form in polluted areas of
Scotland.
34
45.
The diagram below shows some characteristics of two present
day breeds of dog which descended from a wolf-like common
ancestor.
Wolf-like common ancestor
•
•
Husky
Good stamina
Strong
Collie
• Very intelligent
• Good herding instinct
Name and describe the process which humans have used to
produce different breeds of dog.
35
46.
The maps below show the changes in distribution of the red
squirrel in the UK from 1920 to 1990.
(a) Describe the change in distribution between 1920 and 1990.
(b) Suggest reasons for this change.
(c) Discuss the potential impact this could have on biodiversity.
36