GCSE BIOLOGY TEST REVISION QUESTIONS WITH VERIFIED
ANSWERS LATEST 2025 UPDATE.
What are the parts of an animal (and plant) cell? - ANSWER- Nucleus
Cytoplasm
Cell membrane
Mitochondria
What are parts of a plant cell? - ANSWER- Rigid cell wall
Large vacuole
Chloroplasts
(nucleus, cytoplasm, cell membrane and mitochondria)
What does the nucleus do? - ANSWER- Contains DNA that controls what the cell does
What does the cytoplasm do? - ANSWER- Its a gel-like substance where most of the chemical
reactions happpen
What does the cell membrane do? - ANSWER- Holds the cell together and controls what goes
in and out
What does the mitochondria do? - ANSWER- This is where most of the reactions for respiration
take place. Respiration releases energy that the cell needs to work.
What does the rigid cell wall do? - ANSWER- It is made up of cellulose and it gives support
for the cell
,What does the large vacuole do? - ANSWER- Contains cell sap, a weak solution of sugar and
salts
What do chloroplasts do? - ANSWER- This is where photosynthesis occurs. They contain a
green substance called chlorophyll.
What are the features of a bacteria cell? - ANSWER- Chromosomal DNA
Plasmids
Flagellum
Cell wall
What is chromosomal DNA? - ANSWER- Chromosomal DNA controls the cells activities and
replication. It floats free in the cytoplasm.
What are plasmids? - ANSWER- Plasmids are small loops of extra DNA that aren't part of the
chromosome. Plasmids contain genes for things like drug resistance and can be passed between
bacteria.
What is the flagellum? - ANSWER- The flagellum is a long, hair-like structure that rotates to
make the bacterium move.
What does the cell wall do? - ANSWER- Support the cell
What is magnification? - ANSWER- How much bigger the image is that the specimen
How do you work out magnification? - ANSWER- length of image / length of specimen
What is the difference between light microscopes and electron microscopes? - ANSWER- Light
microscopes let us see things like the nuclei, chloroplasts and mitochondria. Electron microscopes
, let us see much smaller things in more detail like the internal structure of mitochondria and
chloroplasts and even tinier things like plasmids.
What is DNA? - ANSWER- DNA is the complex chemical that carries genetic information.
DNA is found in chromosomes which are found in the nucleus of most cells.
What is the structure of DNA? (6marker) - ANSWER- -A DNA molecule has two strands coiled
together in the shape of a double helix.
-The two strands are hold together by chemicals called bases. The four bases are adenine, thymine,
guanine and cytosine.
-The bases are paired, and they always pair up in the same way; A-T and C-G. This is called base
pairing.
-The base pairs are joined together by weak hydrogen bonds.
What is a gene? - ANSWER- A gene is a short piece of DNA that codes for a specific protein.
You have genes for hair structure, eye colour enzymes and every other protein in your body.
Who discovered the structure of DNA? - ANSWER- -Rosalind Franklin and Maurice Wilkins
worked out DNA had a helical structure by directing beams of X-rays onto crystallised DNA and
looking at the patterns of x-rays formed as they bounced off.
-James Watson and Francis Crick used these ideas along with the idea the amount of
adenine+guanine matched the amount of thymine+cytosine to make a model of the DNA molecule
where all the pieces fitted together.
What would be a practical to extract DNA?(6 marker) - ANSWER- -Mash or chop fruit or
vegetable (e.g kiwi) and mix with salty water and detergent to break open the cells and help release
the DNA from the nuclei.
-Add protease enzyme to the filtered mixture to break up proteins in cell membranes and so release
more DNA.
-Add ice cold ethanol carefully down inside the tube into the mixture. The ethanol makes the DNA
separate from the liquid so it is easy to lift out.
ANSWERS LATEST 2025 UPDATE.
What are the parts of an animal (and plant) cell? - ANSWER- Nucleus
Cytoplasm
Cell membrane
Mitochondria
What are parts of a plant cell? - ANSWER- Rigid cell wall
Large vacuole
Chloroplasts
(nucleus, cytoplasm, cell membrane and mitochondria)
What does the nucleus do? - ANSWER- Contains DNA that controls what the cell does
What does the cytoplasm do? - ANSWER- Its a gel-like substance where most of the chemical
reactions happpen
What does the cell membrane do? - ANSWER- Holds the cell together and controls what goes
in and out
What does the mitochondria do? - ANSWER- This is where most of the reactions for respiration
take place. Respiration releases energy that the cell needs to work.
What does the rigid cell wall do? - ANSWER- It is made up of cellulose and it gives support
for the cell
,What does the large vacuole do? - ANSWER- Contains cell sap, a weak solution of sugar and
salts
What do chloroplasts do? - ANSWER- This is where photosynthesis occurs. They contain a
green substance called chlorophyll.
What are the features of a bacteria cell? - ANSWER- Chromosomal DNA
Plasmids
Flagellum
Cell wall
What is chromosomal DNA? - ANSWER- Chromosomal DNA controls the cells activities and
replication. It floats free in the cytoplasm.
What are plasmids? - ANSWER- Plasmids are small loops of extra DNA that aren't part of the
chromosome. Plasmids contain genes for things like drug resistance and can be passed between
bacteria.
What is the flagellum? - ANSWER- The flagellum is a long, hair-like structure that rotates to
make the bacterium move.
What does the cell wall do? - ANSWER- Support the cell
What is magnification? - ANSWER- How much bigger the image is that the specimen
How do you work out magnification? - ANSWER- length of image / length of specimen
What is the difference between light microscopes and electron microscopes? - ANSWER- Light
microscopes let us see things like the nuclei, chloroplasts and mitochondria. Electron microscopes
, let us see much smaller things in more detail like the internal structure of mitochondria and
chloroplasts and even tinier things like plasmids.
What is DNA? - ANSWER- DNA is the complex chemical that carries genetic information.
DNA is found in chromosomes which are found in the nucleus of most cells.
What is the structure of DNA? (6marker) - ANSWER- -A DNA molecule has two strands coiled
together in the shape of a double helix.
-The two strands are hold together by chemicals called bases. The four bases are adenine, thymine,
guanine and cytosine.
-The bases are paired, and they always pair up in the same way; A-T and C-G. This is called base
pairing.
-The base pairs are joined together by weak hydrogen bonds.
What is a gene? - ANSWER- A gene is a short piece of DNA that codes for a specific protein.
You have genes for hair structure, eye colour enzymes and every other protein in your body.
Who discovered the structure of DNA? - ANSWER- -Rosalind Franklin and Maurice Wilkins
worked out DNA had a helical structure by directing beams of X-rays onto crystallised DNA and
looking at the patterns of x-rays formed as they bounced off.
-James Watson and Francis Crick used these ideas along with the idea the amount of
adenine+guanine matched the amount of thymine+cytosine to make a model of the DNA molecule
where all the pieces fitted together.
What would be a practical to extract DNA?(6 marker) - ANSWER- -Mash or chop fruit or
vegetable (e.g kiwi) and mix with salty water and detergent to break open the cells and help release
the DNA from the nuclei.
-Add protease enzyme to the filtered mixture to break up proteins in cell membranes and so release
more DNA.
-Add ice cold ethanol carefully down inside the tube into the mixture. The ethanol makes the DNA
separate from the liquid so it is easy to lift out.
