Year 10 Advanced Science – Genetics Revision
Name: _______________________
Part A : Multiple Choice
Use the following information to answer Questions 1 and 2.
In animals, being unable to produce pigment is called albinism. This condition occurs in humans as well as in
other animals. Albinism is inherited as an autosomal recessive trait.
1. A cross between two individuals, both heterozygous for albinism, could be represented by
(VCE question)
A. AA x AA.
B. aa x aa.
C. Aa x Aa.
D. Aa x aa.
2. A cross that could confirm that a prize-winning dog was a carrier for albinism is
(VCE question)
A.
B.
C.
D.
AA x AA.
aa x aa.
AA x Aa.
Aa x aa.
3. Which of the following is NOT an example of continuous variation?
A. Intelligence
B. Free or attached ear lobes
C. Height
D. Blood pressure
4. Which of the following cannot be inherited?
A. Pneumonia
B. Sickle-cell Anaemia
C. Down’s Syndrome
D. Colourblindness
5. Which is the term used to describe the genotype with two contrasting alleles?
A. Homologous
B. Heterozygous
C. Homozygous
D. Hemizygous
6. Which type of following human cells have the most number of chromosomes?
A. Nerve cell
B. Red blood cell
C. Sperm cell
D. Egg cell
7. A fruit fly has four pairs of chromosomes in its cells. At meiosis, how many different combinations of
maternal and paternal chromosomes are possible in the gametes?
A. 4
B. 6
C. 8
D. 16
8. A plant with red flowers is crossed with a white-flowered plant of the same species. All the seeds, when
grown, produce plants with red flowers. Assuming that the flower colour is controlled by a single pair of
alleles, which allele is dominant and which is recessive?
A. White is dominant and red is recessive
B. Red is dominant and white is recessive
C. Both white and red are dominant
D. Both white and red are recessive
9. What is not true for sex-chromosomes in human?
A. A male has an X chromosome and a Y chromosome.
B. A female has 2 X chromosomes
C. There is no gene in Y chromosome
D. X chromosome is larger than Y chromosome.
10. Eye colour in humans can range from dark brown to light blue and is controlled by multiple genes. Eye
colour is an example of (VCE question)
A. multiple alleles.
B. codominance.
C. polygenic inheritance.
D. discontinuous variation.
11. A goldfish has 94 chromosomes in its somatic cells. The diploid number for a goldfish is
(VCE question)
A.
B.
C.
D.
47
94
188
376
12. Compared with the amount of nuclear DNA in a nerve cell, the amount of nuclear DNA in an unfertilised
egg cell will be (VCE question)
A.
B.
C.
D.
double.
the same.
half.
a quarter.
13. Red-green colour blindness is X-linked in humans. If a male is red-green colour blind, and both parents
have normal colour vision, which of the male's grandparents is most likely to be red-green colour blind?
(VCE question)
A. Maternal grandmother
Maternal grandfather
Paternal grandmother
D. Paternal grandfather
B.
C.
14. Which is found in RNA but not in DNA? (VCE question)
A. adenine
B. cytosine
C. guanine
D. uracil
15. A segment of DNA has one strand with the following sequence of bases.
A G C G C A T A G C A A (VCE question)
The complementary strand of DNA is
A. U C G C G U A U C G U U
B. T C G C C G A T C G T T
C. T C G C G T A T C G T T
D. T C G C A T T A C A U U
Questions 16 and 17 refer to the following
In rabbits, spotted coat (D) is dominant to solid colour (d).
16. A cross that would show whether a spotted individual is heterozygous for coat colour would be (VCE
question)
A. DD  DD
B. Dd  dd
C. dd  dd
D. DD  Dd
17. When two rabbits with spotted coats were mated, they produced some offspring with spotted coats and
some with solid colour. It is reasonable to conclude that (VCE question)
A.
B.
C.
D.
all the offspring with spotted coats have the same genotype
neither the parents are heterozygous
no offspring could be homozygous for spotted coat
all the offspring with solid colour are homozygous
Information for Questions 18 and 19
The following photograph shows the karyotype of a human.
18. This karyotype is for a (VCE question)
Sex
Normal or Abnormal
Diploid number
A.
female
abnormal
2n = 45
B.
female
normal
2n = 48
C.
male
abnormal
2n = 47
D.
male
normal
2n = 46
19. Red-green colourblindness is inherited as a sex-linked recessive gene. A colourblind person with the
karyotype in Figure 2 would have the genotype (VCE question)
A.
B.
C.
D.
XHXh
XhY
XhO
XhXh
20. Structure II in the diagram shows (VCE question)
A.
B.
C.
D.
two chromatids
two centromeres
two chromosomes
four chromatids
Part B: Short answer questions
Question I - Cell Division and Chromosomes [ 32 marks ]
1. A cell in the basal layer of the skin contains 46 chromosomes and divides by mitosis to
produce new skin cells. After ten successive divisions, how many chromosomes will the
basal cell have? Explain your answer [2]
____________________________________________________________________________________________________
2. The drawings below depict stages in the mitotic division of a cell
A
B
C
D
E
(a) Write the letters in the order in which these stages occur. [2]
___________________________________________________________________
(b) How many pairs of chromosomes are there in the cell? [1]
_________________
(c) What is the diploid number of chromosomes in these cells? [1]
____________________________
3. Choose the most appropriate word to complete the sentence.
When chromosomes replicate, they produce _____________________ [1].
tissues, nuclei, chromatids, somatic cells
4. In which three of the following cells is mitosis unlikely to occur?
a sperm cell, an epithelial cell of a villus, a hair cell, a cell in the red bone marrow, a red
blood cell, a lymphocyte, a cell in the basal layer of the skin [3]
_________________________________________________________________________________________
5. An animal has 36 chromosomes in each of its body cells. How many of these chromosomes
came from its male parent? [1]
______________________________________________________
6. Which pairs of chromosomes in the cell shown here are homologous? [3]
___________________________________________________________________________
7. Fill in the missing words. [3]
The _____________________ of a cell contains a fixed number of
chromosomes. Before mitosis, each chromosome
_________________________to produce two __________________________.
8. The following drawings-show the sequence of events early in cell division.
(i)
(ii)
(iii)
(a) Is the division meiotic or mitotic? [1]
___________________
(b) How do you know? Give 2 reasons. [2]
__________________________________________________________________________________________
___________________________________________________________________________________________
9. Give two examples in each case of organs or tissues in which you would expect
(a) meiosis [2] ____________________________________________
(b) mitosis to be taking place. [2] ____________________________________________
10. From the list below, choose the most suitable words to complete the sentence. [8]
cells, gene, gamete, radiation, chromosome, nucleus, ovum, organism
Mutations are changes which occur in a ____________________or a ______________ If a mutation
occurs in a cell which is going to form a __________________ the mutation may affect the whole
_______________ which develops. Down's syndrome results from a ___________________ mutation in
the ____________________. Sickle cell anaemia results from a _________________mutation which affects
________________of the blood system. Exposure to ______________________ may increase the rate of
mutation.
Question II - Heredity
11. In cats, the allele (S) for short fur is dominant to the allele (s) for long fur. [ 6 marks ]
(a) What is the genotype of a true-breeding, long-furred cat? [1] __________________
(b) What is the phenotype of a cat with the genotype Ss? [1] _______________________
(c) In an Ss genotype, which allele is expressed in the phenotype? [1]
_____________________________________________________________________
(d) Which of the fo1lowing genotypes is (i) heterozygous (ii) homozygous dominant?
SS, Ss, ss
(i) ______________________ (ii) _________________________ [3]
12. In rabbits, assume that the dominant allele (B) produces black fur. The allele (b) for white
fur is recessive to B. [ 15 marks ]
(a) What colour fur will each of the following rabbits have? [4]
genotype
Rabbit 1
Rabbit 2
Rabbit 3
Rabbit 4
BB
Bb
bB
bb
_____________
____________
___________
phenotype _____________
(b) Which of them will breed true? [2] _________________________
(c) Which rabbits are homozygous for coat colour? [2] _____________________
(d) If rabbits 1 and 4 were mated together and had 12 babies, how many of these would you
expect to be black? Explain your answer. [3]
________________________________________________________________________________________________________
_________________________________________________________________________________________________________
(e) If rabbits 2 and 3 are interbred and produce several litters, totalling 48 babies, how
many white babies would be predicted by the laws of genetics? [2]
________________________________________________________________________________________________________
_________________________________________________________________________________________________________
(f) If rabbits 3 and 4 are mated together on several occasions and have 50 babies altogether,
how many of their babies would you 'expect' to be black? Explain your answer [2]
________________________________________________________________________________________________________
_________________________________________________________________________________________________________
13. In fruit flies, the allele (n) for ebony (black) body is recessive to the allele (N) for normal
(grey) body. [ 6 marks ]
gametes
(a) Complete the Punnett square, for a
cross between normal (grey-bodied)
flies which are heterozygous for this
allele (i.e. Nn genotypes). [3]
gametes
(b) State the expected proportion of normal
and ebony-bodied flies in a large sample of
the offspring. [2] ____________________________
(c) State the proportion of the normal phenotypes which would be true breeding. [1]
______________________________.
14. Haemophilia (recessive sex-linked disorder) [ 19 marks ]
a) Use appropriate symbols to represent chromosomes and genes and complete the following
table [4]
Normal female = _____________
Carrier female = ______________
Normal male = ______________
Male with haemophilia = _____________
b) Because the male only has sex-linked genes on the ________ chromosome, there is nothing on
the ______ chromosome to mask the disorder on the _______ chromosome. So if a male has
even 1 copy of the disordered gene, he suffers from the disorder. A female can carry 1 disordered
gene on one _______ chromosome but still have a normal gene to mask it on the other ________
chromosome. A "carrier female" usually doesn't suffer from the disorder, she just carries it and can
pass it on .... usually to her SONS. [5]
,
c) Cross a carrier female (for haemophilia) with a normal male. Of all their offspring, what is the
probability they will produce a haemophiliac son? [1+3]
__________________
d) Cross a haemophiliac female with a normal male. Of all their offspring, what is the probability
they will produce a haemophiliac daughter? [1+3]
_____________________
e) A "carrier female" usually doesn't suffer from the disorder, she just carries it and can pass it on
.... usually to her SONS. Why? [2]
______________________________________________________________________________
______________________________________________________________________________
15. The genetic disorder phenylketonuria (PKU) is caused by a recessive allele (n). The family
tree below shows the incidence of the disease over three generations. [ 13 marks ]
grandparents
parents
wife
Peter
Alan
Jane
husband
children
KEY
normal
male
male
with
PKU
normal
female
female
with
PKU
(a) What can you deduce about the genotypes of the grandparents? [2]
________________________________________________________________________________________________
(b) Explain your reasoning. [2]
_________________________________________________________________________________________________
________________________________________________________________________________________________
(c) What is the genotype of Jane's husband? [1] ______________
(d) Explain your reasoning. [2]
_________________________________________________________________________________________________
________________________________________________________________________________________________
(e) What are the chances that Peter is the carrier of the PKU allele that resulted in
having an affected son? Explain it [2]
_________________________________________________________________________________________________
________________________________________________________________________________________________
(f) If Jane had been normal, what are the possible genotypes of the grandparents? [2]
_________________________________________________________________________________________________
(g) Is it possible that the allele for PKU is sex-linked? Why? [2] ____________________________
__________________________________________________________________________________________________