GENERAL CERTIFICATE OF
SECONDARY EDUCATION (GCSE)
BIOLOGY – PAPER 1 AND PAPER 2 COMBINED
EXAMINATION
COMPREHENSIVE MASTERY AND LIFE SCIENCES
EXAMINATION (2026)
SPRING SEMESTER EXAMINATION
2025/2026
Explain how the leaves are adapted to maximize the amount of carbon dioxide that gets
into their cells
1) The exchange surface in a leaf is covered in stomata which the carbon dioxide diffuses
through
2) The leaf has a flattened shape which increases the area of its exchange surface,
therefore it's more effective
3) The walls of the cells inside the leaf act as another exchange surface
4) The air spaces inside the leaf increase the area of the exchange surface which
increases the chance for carbon dioxide to enter the cells
What affects the rate of diffusion?
Concentration gradient - the steeper the gradient, the faster the rate
Temperature - the higher the temperature, the faster the rate (the particles have more
energy thus move around faster)
Surface area - the larger it is, the faster the rate
1|Page
,Diffusion distance - the shorter the distance, the faster the rate
Examples of active transport
Plants = Root hairs absorb minerals and water. Each branch of a root will be covered in
tiny hairs, therefore increasing the surface area for the absorption of minerals and water.
The concentration of minerals is usually higher in the root hair cells than in the soil
around them, therefore they can't use diffusion for this process.
Animals = Glucose is taken in from the gut and from kidney tubules.
How are alveoli in the lungs specialized to maximize the diffusion of oxygen and carbon
dioxide?
-an enormous surface area
-a moist lining for dissolving gases
-very thin walls
-a good blood supply
How do fish respire?
-Water enters the fish through the mouth and passes out through the gills
-During this process, oxygen diffuses from the water into the blood in the gills and
carbon dioxide diffuses from the blood into the water
How are fish adapted for gas exchange?
-Each gill is made up of lots of gill filaments which create a large surface area for the
exchange of gases
-Gill filaments are covered in lamellae which increase the surface even more
-The lamellae have lots of blood capillaries to speed up diffusion
2|Page
,-The lamellae have a thin surface layer of cells to minimize the diffusion distance
-Blood flows through the lamellae one way and water flows over in the opposite
direction which maintains a higher concentration gradient between the blood and the
water
-The concentration of oxygen in the water is always higher than that in the blood to
maximize the amount of oxygen diffusion from the water into the blood
Microscopy Practical - Preparing the Slide
1) Add a drop of water to the middle of a clean slide
2) Cut up an onion & separate it out into layers. Use tweezers to peel off some epidermal
tissue from the bottom of one of the layers
3) Using the tweezers, place the epidermal tissue into the water on the slide
4) Add a drop of iodine solution - a stain used to highlight objects in a cell by adding
colour to them
5) Place a cover slip on top - stand the cover slip upright on the slide, next to the water
droplet. Then, carefully tilt & lower it so it covers the specimen. Try not to get any air
bubbles under there - there'll obstruct your view
Microscopy Practical - Using a Light Microscope
1) Clip the slide you've prepared onto the stage
2) Select the lowest-powered objective lens
3) Use the coarse adjustment knob to move the stage up to just below the objective lens
4) Look down the eyepiece. Use the coarse adjustment knob to move the stage
downwards until the image is roughly in focus
5) Adjust the focus with the fine adjustment knob, until you get a clear image of what's
on the slide
Microscopy Practical - Drawing Observations
3|Page
, 1) Draw what you see under the microscope using a pencil with a sharp point
2) Make sure your drawing takes up at least half of the space available & that it is drawn
with clear, unbroken lines
3) Your drawing should not include any colouring or shading
4) If you are drawing cells, the subcellular structures should be drawn in proportion
5) Include a title & write down the magnification that it was observed under
6) Label the important features of your drawing using straight, uncrossed lines
What happens during binary fission?
1) The circular DNA & plasmid(s) replicate
2) The cell gets bigger & the circular DNA strands move to opposite poles of the cell
3) The cytoplasm begins to divide & new cell walls begin to form
4) The cytoplasm divides & two daughter cells are produced. Each daughter cell has one
copy of the circular DNA, but can have a variable number of copies of the plasmid(s)
What is binary fission?
A type of simple cell division used by prokaryotic cells to reproduce & split into two
What conditions do bacteria need to divide?
1) Warm environment
2) Lots of nutrients
What is the mean division time?
The average amount of time it takes for one bacterial cell to divide into two
4|Page
SECONDARY EDUCATION (GCSE)
BIOLOGY – PAPER 1 AND PAPER 2 COMBINED
EXAMINATION
COMPREHENSIVE MASTERY AND LIFE SCIENCES
EXAMINATION (2026)
SPRING SEMESTER EXAMINATION
2025/2026
Explain how the leaves are adapted to maximize the amount of carbon dioxide that gets
into their cells
1) The exchange surface in a leaf is covered in stomata which the carbon dioxide diffuses
through
2) The leaf has a flattened shape which increases the area of its exchange surface,
therefore it's more effective
3) The walls of the cells inside the leaf act as another exchange surface
4) The air spaces inside the leaf increase the area of the exchange surface which
increases the chance for carbon dioxide to enter the cells
What affects the rate of diffusion?
Concentration gradient - the steeper the gradient, the faster the rate
Temperature - the higher the temperature, the faster the rate (the particles have more
energy thus move around faster)
Surface area - the larger it is, the faster the rate
1|Page
,Diffusion distance - the shorter the distance, the faster the rate
Examples of active transport
Plants = Root hairs absorb minerals and water. Each branch of a root will be covered in
tiny hairs, therefore increasing the surface area for the absorption of minerals and water.
The concentration of minerals is usually higher in the root hair cells than in the soil
around them, therefore they can't use diffusion for this process.
Animals = Glucose is taken in from the gut and from kidney tubules.
How are alveoli in the lungs specialized to maximize the diffusion of oxygen and carbon
dioxide?
-an enormous surface area
-a moist lining for dissolving gases
-very thin walls
-a good blood supply
How do fish respire?
-Water enters the fish through the mouth and passes out through the gills
-During this process, oxygen diffuses from the water into the blood in the gills and
carbon dioxide diffuses from the blood into the water
How are fish adapted for gas exchange?
-Each gill is made up of lots of gill filaments which create a large surface area for the
exchange of gases
-Gill filaments are covered in lamellae which increase the surface even more
-The lamellae have lots of blood capillaries to speed up diffusion
2|Page
,-The lamellae have a thin surface layer of cells to minimize the diffusion distance
-Blood flows through the lamellae one way and water flows over in the opposite
direction which maintains a higher concentration gradient between the blood and the
water
-The concentration of oxygen in the water is always higher than that in the blood to
maximize the amount of oxygen diffusion from the water into the blood
Microscopy Practical - Preparing the Slide
1) Add a drop of water to the middle of a clean slide
2) Cut up an onion & separate it out into layers. Use tweezers to peel off some epidermal
tissue from the bottom of one of the layers
3) Using the tweezers, place the epidermal tissue into the water on the slide
4) Add a drop of iodine solution - a stain used to highlight objects in a cell by adding
colour to them
5) Place a cover slip on top - stand the cover slip upright on the slide, next to the water
droplet. Then, carefully tilt & lower it so it covers the specimen. Try not to get any air
bubbles under there - there'll obstruct your view
Microscopy Practical - Using a Light Microscope
1) Clip the slide you've prepared onto the stage
2) Select the lowest-powered objective lens
3) Use the coarse adjustment knob to move the stage up to just below the objective lens
4) Look down the eyepiece. Use the coarse adjustment knob to move the stage
downwards until the image is roughly in focus
5) Adjust the focus with the fine adjustment knob, until you get a clear image of what's
on the slide
Microscopy Practical - Drawing Observations
3|Page
, 1) Draw what you see under the microscope using a pencil with a sharp point
2) Make sure your drawing takes up at least half of the space available & that it is drawn
with clear, unbroken lines
3) Your drawing should not include any colouring or shading
4) If you are drawing cells, the subcellular structures should be drawn in proportion
5) Include a title & write down the magnification that it was observed under
6) Label the important features of your drawing using straight, uncrossed lines
What happens during binary fission?
1) The circular DNA & plasmid(s) replicate
2) The cell gets bigger & the circular DNA strands move to opposite poles of the cell
3) The cytoplasm begins to divide & new cell walls begin to form
4) The cytoplasm divides & two daughter cells are produced. Each daughter cell has one
copy of the circular DNA, but can have a variable number of copies of the plasmid(s)
What is binary fission?
A type of simple cell division used by prokaryotic cells to reproduce & split into two
What conditions do bacteria need to divide?
1) Warm environment
2) Lots of nutrients
What is the mean division time?
The average amount of time it takes for one bacterial cell to divide into two
4|Page
