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Q1.
Cells
Scientists use a microscope to study how cells work.
(a) The diagram shows a light microscope.
Complete the sentence by putting a cross ( ) in the box next to your answer.
To make the image of the cell appear larger you would
(1)
A turn the focusing wheel
B change the objective lens
C clean the stage
D move the mirror
(b) (i) Draw one straight line from each cell to the group of organisms to which it belongs.
(2)
(ii) Put a cross ( ) in the box next to your answer.
Which plant cell structures use sunlight for photosynthesis?
(1)
A chloroplasts
B cytoplasm
C mitochondria
D vacuoles
(iii) The function of the cell membrane is to allow certain substances into and out of the cell.
Describe how molecules like water can pass through a cell membrane but molecules like
starch cannot.
(2)
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(c) A scientist looks at a cell with a microscope that has a magnification of times 40.
The cell is 0.1 mm long.
Calculate the size of the magnified image.
(2)
answer ..................................................................................
Q2.
Cells
(a) The diagrams show a bacterial cell, a plant cell and an animal cell.
Structure X is found in all three cells.
(i) Complete the sentence by putting a cross ( ) in the box next to your answer.
Structure X is the
(1)
A cell membrane
B cell wall
C cytoplasm
D nucleus
(ii) Many bacteria have one or more flagella whereas most animal cells have no flagella.
State one other difference between a bacterial cell and an animal cell.
(1)
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(b) Scientists use microscopes to magnify cells.
(i) Use words from the box to complete the sentences.
(2)
The magnification of a light microscope can be varied by changing
the............................................................................
The electron microscope can magnify
images...........................................................................than the light microscope.
(ii) The diagram shows a sperm cell that has been magnified 100 000 times.
Calculate the actual length of the sperm cell.
(2)
length of sperm cell = .................................................................... mm
(iii) Explain why a human sperm cell contains more mitochondria than most other types of
cell in the human body.
(2)
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Q3.
Question
number
(a)
Answer
Mark
B
Question
number
(b)(i)
(1)
Answer
Mark
1 mark for each correct
line
(2)
Question
number
(b)(ii)
A
Question
number
(b)(iii)
Question
number
(c)
Answer
Mark
(1)
Answer
Acceptable
answers
a description
including the
following: cell
membranes have
small gaps/holes in
them (1) water is
small enough to fit
through
them/starch is too
big to fit through
them (1)
(2)
Answer
4 (1) mm (1)
Mark
Mark
(2)
Q4.
Question
Number
(a)(i)
Question
Number
(a)(ii)
Question
Number
(b)(i)
Question
Number
(b)(ii)
Question
Number
(b)(iii)
Answer
A
Answer
Acceptable
answers
Acceptable
answers
bacterial cells have
plasmids
Any one of the
following points
• bacterial cells
have a cell wall
(animal cells do
not) (1) • bacterial
cells do not have a
nucleus (animal
cells do) (1)
• bacterial cells
have circular DNA /
chromosomal DNA
(animal cells do
not) (1)
Answer
Acceptable
answers
• objective lens
(1) • more (1)
Answer
Acceptable
answers
calculation (1)
correct answer (1)
= 0.00130 / 1.3 ×
10-3
Answer
An explanation
including two of
the following points
• mitochondria are
sites of respiration
for energy (1)
• sperm requires
a lot of energy (1)
• for movement /
swimming / to
move the flagellum
(1)
Acceptable
answers
Mark
(1)
Mark
(1)
Mark
(2)
Mark
(2)
Mark
(2)