B5 Stem cells exam questions
Q1.
The diagram shows how cells from human embryos can be used to grow ‘replacement
body parts’ for humans.
Sue Medaris/University of Wisconsin-Madison
(a)
Complete the following sentences.
(i)
The fertilised egg has ................................. sets of genetic information.
(1)
(ii)
The fertilised egg divides to form the 5-day-old embryo by a process
called ................................................................
(1)
(b)
Some statements about stem cells are given below.
Tick ( ) two advantages and two disadvantages of using stem cells to grow
‘replacement body parts’ for humans.
Advantage
Tick ( )
Stem cells can grow into many different kinds of
body cells.
Stem cells may grow out of control.
Large numbers of stem cells can be grown in the
Page 1
Disadvantage
Tick ( )
laboratory.
Stem cells may be used to treat some human
diseases.
Collecting and growing stem cells is expensive.
Patients treated with stem cells may need to take
drugs for the rest of their life to prevent rejection.
(4)
(Total 6 marks)
Q2.
The diagram shows one way that stem cells can be produced from human embryos.
Sue Medaris/University of Wisconsin-Madison
(a)
Stem cells can be used to treat a condition such as paralysis.
Explain why.
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........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
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(b)
During pregnancy, an umbilical cord and a placenta join the embryo to the mother.
At birth the umbilical cord is cut.
Stem cells can be obtained from the umbilical cord.
Many people think that the stem cells for treating human conditions should be
obtained from umbilical cords rather than human embryos.
Suggest one reason why.
........................................................................................................................
........................................................................................................................
(1)
(c)
Stem cells divide by mitosis. Gametes are formed by meiosis.
Give two differences between mitosis and meiosis.
1 .....................................................................................................................
........................................................................................................................
2 .....................................................................................................................
........................................................................................................................
(2)
(Total 5 marks)
Q3.
(a)
The diagram shows how pigs can be cloned.
Page 3
For each question write the correct letter in the box.
Which structure, A, B, C or D is:
(i)
an egg cell
(1)
(ii)
a nucleus
(1)
(iii)
an embryo?
(1)
(b)
Walking onion plants grow a bunch of bulblets (tiny bulbs).
The bulblets start to grow and the stalks bend over with the weight of the new growth.
This makes the onion plant seem to walk across the garden.
Page 4
Producing plants in this way is called asexual reproduction.
Use words from the box to complete the following sentences.
chromosome
clone
gamete
gene
parent
Asexual reproduction needs only one .............................................. .
Asexual reproduction does not involve production of a ......................................... .
The daughter plant is called a ................................................ .
(3)
(Total 6 marks)
Q4.
The diagram shows how an immature egg could be used either to produce cells to treat
some human diseases or to produce a baby.
Page 5
What are these cells called and why are they so useful?
Scientists may be allowed to use this technique to produce cells to treat some human
diseases, but not to produce babies.
Using information from the diagram, suggest an explanation for this.
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(Total 4 marks)
Why are the cells produced so useful for treating diseases? Give examples. ( 4 marks)
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M1.
(a)
(i)
two
1
(ii)
mitosis
1
(b)
Adv.
Disadv.
Stem cells can grow into
many different kinds of body
cells.
Stem cells may grow out of
control.
Large numbers of stem cells
can be grown in the
laboratory.
Stem cells may be used to
treat some human diseases.
Collecting and growing stem
cells is expensive.
Patients treated with stem
cells need to take drugs for
the rest of their life to prevent
rejection.
1 mark for each correctly ticked advantage up to a maximum
of
2 marks
1 mark for each correctly ticked disadvantage up to a
maximum
of 2 marks
deduct 1 mark each for every incorrect box ticked in each
column up to a maximum of 2 deductions in each column
4
[6]
Page 7
M2.
(a)
because stem cells can (be made) to differentiate
1
into nerve / muscle cells
1
(b)
ethical issues with destruction / damage to embryo
1
(c)
mitosis one cell division, meiosis two cell division
1
cells produced by mitosis have two sets of chromosomes,
cells produced by meiosis have one set of chromosomes
accept cells produced by mitosis are genetically identical,
cells produced by meiosis have some genetic differences
1
[5]
M3.
(a)
(i)
D
1
(ii)
C
1
(iii)
B
1
(b)
parent
1
gamete
1
clone
1
[6]
Page 8
M4.
any four from:
•
cells used to treat diseases do not go on to produce a baby
•
produces identical cells for research
•
cells would not be rejected
•
allow cells can form different types of cells
•
(immature) egg contains only genetic information / DNA /
genes / chromosomes from mother or there is only one parent
•
asexual / no mixing of genetic material / no sperm involved /
no fertilisation or chemical causes development
•
baby is a clone
•
reference to ethical / moral / religious issues
allow ethically wrong
NB cloning is illegal gains 2 marks
ignore unnatural
•
risk of damage to the baby
in correct context
[4]
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