IGCSE BIOLOGY | TOP SCORES MADE SIMPLE |
TRUSTED TEST SOLUTIONS!
What does an animal cell consist of? Answer: Cell membrane, cytoplasm,
mitochondria, nucleus
What does a plant cell consist of? Answer: Permanent vacuole, cell membrane, cell
wall, mitochondria, chloroplasts which are full of chlorophyll, cytoplasm, nucleus
What is their role of the nucleus? Answer: Controls the activity of the cells
What is the role of the cell membrane? Answer: Selectively permeable membrane
which controls the substances passing in and out of the cell
What is the role of mitochondria? Answer: Carry out some of the reactions of
respiration to release energy that the cell can use
What is the role of cytoplasm? Answer: Complex material made of many different
structures where all the chemical reactions take place
What is the role of the cell wall? Answer: Made of carbohydrate called cellulose
which is a tough material that helps the cell keep its shape,it is freely permeable
What is the role of chloroplasts? Answer: These contain chlorophyll and are green.
The chloroplasts absorb light energy to make food in the process of photosynthesis
What is the role of the vacuole? Answer: This is a permanent feature of the cell and
is filled with cell sap which is a store of dissolved sugars, mineral ions and other
solutes
What is a catalyst and state the link between a catalyst and enzyme Answer: An
enzyme is a biological catalyst which means that it speeds up a reaction without
being used up itself
1
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,How are the activities of a cell controlled? Answer: The nucleus contains genes,
which control the production of enzymes, which catalyst reactions in the cytoplasm
What is a metabolic reaction? Answer: A chemical reaction taken place inside a cell
Describe th process of enzyme 'lock and key' action Answer: 1. The substrate
enters the enzymes active site as it's active site is complimentary to the enzymes
forming an enzyme substrate complex
2. The reaction takes place and products are formed which leave the active site
Name one factor which affects enzymes Answer: Temperature: in the human body
work best at 37C which is their optimum temperature. After this point the enzymes
departure as the active site changes shape. Before this point, as the temperature
rises, so does the rate of reaction as it will give the molecules of molecules of
enzyme and substrate more energy, so they will collide more frequently
Describe an investigation which shows the effect of temperature on enzymes
Answer: Starch and amylase:
C--> change the temperature of each solution of amylase and starch
O--> Use the same amount of starch and amylase in each solution and keep them in
the water baths for the same amount of time
R--> Repeat the tests for each temperature
M-->Use iodine to test for starch once you've placed the solution on a spotting tile.
Time in minutes and when iodine has changed colour from black/brown- yellow no
more starch is present
S--> Keep the concentration the same so the same amount of amylase and starch in
each test tube and the length of time in the water bath.
How do cells get energy and what can this energy be used for? Answer: Get energy
through the process of respiration and energy can be used to contract muscle cells
to produce movement, for active transport of ions and minerals, building large
2
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,molecules such as proteins and cell division and also release glucose in small
amounts when aerobic
What is the word and symbol equation for aerobic respiration? Answer: Glucose +
Oxygen --> Carbon Dioxide + Water (+ Energy)
C6H12O6 + 6O2 --> 6CO2 + 6H2O (+ Energy)
What is anaerobic respiration and how does it differ from aerobic respiration?
Answer: Anaeobic respiration is when cells respite without the use of oxygen. Unlike
aerobic respiration glucose is not completely broken down and less energy is
released.
Give two examples where cells respite anaerobically Answer: In yeast and muscle
cells
State the word and symbol equation which occurs when yeast resources
anaerobically Answer: Glucose --> Ethanol + Carbon Dioxide (+ Some energy)
C6H12O6 --> 2C2H5OH + 2CO2 (+Some Energy)
State the word and symbol equation which occurs when muscle cells respite
anaerobically Answer: Glucose --> Ethanol (+ Some energy)
C6H12O6 --> 2C3H6O3 (+Some Energy)
What is oxygen debt? Answer: The volume of oxygen needed to completely oxidize
the lactic acid that builds up in the body during anaerobic respiration
Describe the term 'Diffusion' Answer: Diffusion is the movement of substances (ions
and molecules) from a high concentration to a low concentration (down the
concentration gradient) with the help of kinetic energy of the particles.
What can speed up the rate of diffusion? Answer: A higher concentration gradient
Higher temperature which means that the particles have more kinetic energy
Distance is decreased
3
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, Surface area increased
Describe the term 'active transport' Answer: Active transport is when substance
move from a high concentration to a low concentration (up the concentration
gradient) with the use of ATP from respiration.
The leaf: describe what happens with carbon dioxide and oxygen when a leaf cell is
photosynthesising Answer: The concentration of CO2 is greater outside the leaf so
diffuses into the cell to be used for photosynthesis whilst oxygen in the leaf is more
concentrated so diffuses out of the leaf cell
Describe the term 'osmosis' Answer: Osmosis is the diffusion of water molecules
from high water potential to a low water potential through a partially permeable
membrane.
Give an example where osmosis occurs Answer: In plant roots
Describe an experiment to investigate diffusion Answer: Demonstration of diffusion
in a jelly:
Using agar blocks dyed with potassium Permanganate and dilute hydrochloric acid in
a breaker. Agar jelly has the consistency similar to the cytoplasm of a cell which
means that it has a high water content so it can show how substances diffuse
through a cell. When hydrochloric acid comes into contact with potassium
permanganate, the purple colour.
For the experiment a Petri dish is prepared which contains a 2cm deep layer of agar
jelly and 3 cubes of different sizes are cut out (2cm, 1cm and 0.5cm). They are the
dropped into a breaker of hydrochloric acid at the same time and timed.
What is a multicellular organs fertilized egg called? Answer: A Zygote
What are 6 specialised cells? Answer: 1. Nerve cell (neurone)
2. Smooth muscle cell from the wall of the intestine
3. Xylem vessel from the plant stem
4
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TRUSTED TEST SOLUTIONS!
What does an animal cell consist of? Answer: Cell membrane, cytoplasm,
mitochondria, nucleus
What does a plant cell consist of? Answer: Permanent vacuole, cell membrane, cell
wall, mitochondria, chloroplasts which are full of chlorophyll, cytoplasm, nucleus
What is their role of the nucleus? Answer: Controls the activity of the cells
What is the role of the cell membrane? Answer: Selectively permeable membrane
which controls the substances passing in and out of the cell
What is the role of mitochondria? Answer: Carry out some of the reactions of
respiration to release energy that the cell can use
What is the role of cytoplasm? Answer: Complex material made of many different
structures where all the chemical reactions take place
What is the role of the cell wall? Answer: Made of carbohydrate called cellulose
which is a tough material that helps the cell keep its shape,it is freely permeable
What is the role of chloroplasts? Answer: These contain chlorophyll and are green.
The chloroplasts absorb light energy to make food in the process of photosynthesis
What is the role of the vacuole? Answer: This is a permanent feature of the cell and
is filled with cell sap which is a store of dissolved sugars, mineral ions and other
solutes
What is a catalyst and state the link between a catalyst and enzyme Answer: An
enzyme is a biological catalyst which means that it speeds up a reaction without
being used up itself
1
APPHIA - Crafted with Care and Precision for Academic Excellence.
,How are the activities of a cell controlled? Answer: The nucleus contains genes,
which control the production of enzymes, which catalyst reactions in the cytoplasm
What is a metabolic reaction? Answer: A chemical reaction taken place inside a cell
Describe th process of enzyme 'lock and key' action Answer: 1. The substrate
enters the enzymes active site as it's active site is complimentary to the enzymes
forming an enzyme substrate complex
2. The reaction takes place and products are formed which leave the active site
Name one factor which affects enzymes Answer: Temperature: in the human body
work best at 37C which is their optimum temperature. After this point the enzymes
departure as the active site changes shape. Before this point, as the temperature
rises, so does the rate of reaction as it will give the molecules of molecules of
enzyme and substrate more energy, so they will collide more frequently
Describe an investigation which shows the effect of temperature on enzymes
Answer: Starch and amylase:
C--> change the temperature of each solution of amylase and starch
O--> Use the same amount of starch and amylase in each solution and keep them in
the water baths for the same amount of time
R--> Repeat the tests for each temperature
M-->Use iodine to test for starch once you've placed the solution on a spotting tile.
Time in minutes and when iodine has changed colour from black/brown- yellow no
more starch is present
S--> Keep the concentration the same so the same amount of amylase and starch in
each test tube and the length of time in the water bath.
How do cells get energy and what can this energy be used for? Answer: Get energy
through the process of respiration and energy can be used to contract muscle cells
to produce movement, for active transport of ions and minerals, building large
2
APPHIA - Crafted with Care and Precision for Academic Excellence.
,molecules such as proteins and cell division and also release glucose in small
amounts when aerobic
What is the word and symbol equation for aerobic respiration? Answer: Glucose +
Oxygen --> Carbon Dioxide + Water (+ Energy)
C6H12O6 + 6O2 --> 6CO2 + 6H2O (+ Energy)
What is anaerobic respiration and how does it differ from aerobic respiration?
Answer: Anaeobic respiration is when cells respite without the use of oxygen. Unlike
aerobic respiration glucose is not completely broken down and less energy is
released.
Give two examples where cells respite anaerobically Answer: In yeast and muscle
cells
State the word and symbol equation which occurs when yeast resources
anaerobically Answer: Glucose --> Ethanol + Carbon Dioxide (+ Some energy)
C6H12O6 --> 2C2H5OH + 2CO2 (+Some Energy)
State the word and symbol equation which occurs when muscle cells respite
anaerobically Answer: Glucose --> Ethanol (+ Some energy)
C6H12O6 --> 2C3H6O3 (+Some Energy)
What is oxygen debt? Answer: The volume of oxygen needed to completely oxidize
the lactic acid that builds up in the body during anaerobic respiration
Describe the term 'Diffusion' Answer: Diffusion is the movement of substances (ions
and molecules) from a high concentration to a low concentration (down the
concentration gradient) with the help of kinetic energy of the particles.
What can speed up the rate of diffusion? Answer: A higher concentration gradient
Higher temperature which means that the particles have more kinetic energy
Distance is decreased
3
APPHIA - Crafted with Care and Precision for Academic Excellence.
, Surface area increased
Describe the term 'active transport' Answer: Active transport is when substance
move from a high concentration to a low concentration (up the concentration
gradient) with the use of ATP from respiration.
The leaf: describe what happens with carbon dioxide and oxygen when a leaf cell is
photosynthesising Answer: The concentration of CO2 is greater outside the leaf so
diffuses into the cell to be used for photosynthesis whilst oxygen in the leaf is more
concentrated so diffuses out of the leaf cell
Describe the term 'osmosis' Answer: Osmosis is the diffusion of water molecules
from high water potential to a low water potential through a partially permeable
membrane.
Give an example where osmosis occurs Answer: In plant roots
Describe an experiment to investigate diffusion Answer: Demonstration of diffusion
in a jelly:
Using agar blocks dyed with potassium Permanganate and dilute hydrochloric acid in
a breaker. Agar jelly has the consistency similar to the cytoplasm of a cell which
means that it has a high water content so it can show how substances diffuse
through a cell. When hydrochloric acid comes into contact with potassium
permanganate, the purple colour.
For the experiment a Petri dish is prepared which contains a 2cm deep layer of agar
jelly and 3 cubes of different sizes are cut out (2cm, 1cm and 0.5cm). They are the
dropped into a breaker of hydrochloric acid at the same time and timed.
What is a multicellular organs fertilized egg called? Answer: A Zygote
What are 6 specialised cells? Answer: 1. Nerve cell (neurone)
2. Smooth muscle cell from the wall of the intestine
3. Xylem vessel from the plant stem
4
APPHIA - Crafted with Care and Precision for Academic Excellence.
