AQA GCSE Triple Science - Biology
What are eukaryotic cells? - ANS -Cells that are more complex and have a nucleus (animal and
plant cells)
What are prokaryotic cells? - ANS -Cells that are smaller and simpler, and don't have a nucleus
but still have genetic information (bacteria)
What are eukaryotes? - ANS -Organisms made of eukaryotic cells
What is a prokaryote? - ANS -A prokaryotic cell (it's a single celled organism)
What is cytoplasm? - ANS -A liquid gel in which most of the chemical reactions needed for life
take place. It contains enzymes that control these chemical reactions
In what types of cells is cytoplasm found? - ANS -Animal, plant, algae, and bacteria cells
What is the cell membrane? - ANS -It holds the cell together and controls the passage of
substances in and out of the cell
In what types of cells is a cell membrane found? - ANS -Animal, plant, algae, and bacteria cells
What is the nucleus? - ANS -It carries the instructions for making new cells or organisms and
controls all activities of the cell
In what types of cell is a nucleus found? - ANS -Animal, plant, and algae cells
What is the cell wall? - ANS -It is made of cellulose in plants and peptidoglycan in bacteria. It
strengthens and supports the cell.
In what types of cell is a cell wall found? - ANS -Plant, and bacteria cells
What are chloroplasts? - ANS -They are found in the green parts of a plant, and they contain
chlorophyll which allows the cell to create food and light energy
In what types of cell are chloroplasts found? - ANS -Plant, and algae cells
What are ribosomes? - ANS -They are the site of protein synthesis. All the proteins needed in
the cell are made here. The ribosomes are attached to the RER (rough endoplasmic reticulum)
In what types of cell are ribosomes found? - ANS -Animal, and plant cells
,What are mitochondria? - ANS -They are structures in the cytoplasm. Oxygen is used, and
energy is released during respiration here
In what types of cell are mitochondria found? - ANS -Animal, plant, and algae cells
What is a permanent vacuole? - ANS -It is a space in the cytoplasm filled with cell sap. It is
important for keeping the cell rigid to support the plant
In what types of cell is a permanent vacuole found? - ANS -Plant, and algae cells
What is a plasmid? - ANS -A small, circular piece of DNA that carries genes additional to those
in the main genetic material
What two features do bacteria cells NOT have? - ANS -Chloroplasts and mitochondria
How do light microscopes work? - ANS -They use light and lenses to form an image of a
specimen and magnify it
What can we see using a microscope? - ANS -Individual cells and large sub-cellular structures,
like nuclei
What do electron microscopes use to form an image? - ANS -Electrons
Out of electron and light microscopes, which has a higher resolution? - ANS -Electron
microscopes
What can we see with electron microscopes? - ANS -The internal structure of mitochondria and
chloroplasts, ribosomes, and plasmids
What is the formula for magnification? - ANS -Magnification is image size divided by real size
How do you convert from micrometres into millimetres? - ANS -Divide by 1000
What is a flagellum for? - ANS -Locomotion
In what type of cell is a flagellum found? - ANS -Bacteria
What are nerve cells specialised to do? - ANS -Carry impulses around an organism. They
provide a quick communication system
What are four adaptations of nerve cells? - ANS -Lots of dendrites to connect with other cells
Axon that carries nerve impulses from one place to another
Synapses adapted to pass impulses on using transmitter chemicals
,Long so they cover more distance
What is differentiation? - ANS -The process where a cell changes to become specialised
What are stem cells? - ANS -Undifferentiated cells
What are sperm cells specialised to do? - ANS -Get the male DNA to the female DNA by
fertilising an egg
What are three adaptations of sperm cells? - ANS -Long tail to help it swim
Lots of mitochondria to provide the energy needed for the sperm cell to move
Digestive enzymes in the head to digest the egg cell membrane
What are muscle cells specialised to do? - ANS -Contract and relax to move the bones of the
skeleton
What are two adaptations of muscle cells? - ANS -Long so they have space to contract
Contain lots of mitochondria to generate the energy needed for contraction
What are root hair cells specialised to do? - ANS -Absorb water and minerals
What is one adaptation of a root hair cell? - ANS -Large surface area for absorbing water and
mineral ions from the soil
What are photosynthetic cells specialised to do? - ANS -Carry out photosynthesis
What are three adaptations of photosynthetic cells? - ANS -Contain chloroplasts, which contain
chlorophyll for photosynthesis
Positioned in continuous layers in the leaves and outer layers of the stem of a plant to help
absorb light
Have a large permanent vacuole to keep the cell rigid
What are xylem cells specialised to do? - ANS -Carry water and mineral ions from the roots to
the highest leaves and shoots
What are two adaptations of xylem cells? - ANS -Xylem cells are alive when they are first
formed, but die and form hollow tubes for the water and mineral ions to pass through
They have rings of lignin to help withstand the pressure of water in the plant
What are phloem cells specialised to do? - ANS -Carry food around the plant (translocation)
What are two adaptations of phloem cells? - ANS -The cell walls between the cells break down
and form sieve plates which allow water and dissolved food to move as needed.
They are supported by the companion cells that transfer the energy needed to move the food.
, Where are stem cells found in adults? - ANS -Bone marrow
What is the difference between embryonic stem cells and adult stem cells? - ANS -Adult stem
cells can only turn into certain cell types, like blood cells, whereas embryonic stem cells can turn
into any type of cells
How can adult stem cells be used to cure disease? - ANS -Stem cells transferred from the bone
marrow of a healthy person can replace faulty blood cells in the patient who receives them
How can embryonic stem cells be used? - ANS -Make insulin-producing cells for diabetics
Nerve cells for people paralysed by spinal injuries
What is therapeutic cloning? - ANS -The embryo could be made to have the same genetic
information as the patient, meaning the stem cells produced wouldn't be rejected by the patient's
body as the genes are the same.
What is a risk of using stem cells in medicine? - ANS -Stem cells may get contaminated with a
virus, which could be passed on to the patient, making them sicker
Give one argument against using stem cell research - ANS -Each one is a potential human life
Give one argument for using stem cell research - ANS -Curing patients who are suffering is
more important than the rights of embryos
How can stem cells be used for plants? - ANS -Produce clones quickly and cheaply
Grow more plants of rare species
Grow crops that have desired features (e.g. disease resistance)
What are chromosomes? - ANS -Coiled up lengths of DNA molecules
How many copies of each chromosome does a body cell normally have? - ANS -Two - one from
each parent
How many pairs of chromosomes does a human cell have? - ANS -23
What is mitosis? - ANS -Division of cells
What do multicellular organisms use mitosis for? - ANS -Growth, or to replace cells that have
been damaged
What do cells do before they divide? - ANS -Increase their sub-cellular structures, like
mitochondria and ribosomes
What are eukaryotic cells? - ANS -Cells that are more complex and have a nucleus (animal and
plant cells)
What are prokaryotic cells? - ANS -Cells that are smaller and simpler, and don't have a nucleus
but still have genetic information (bacteria)
What are eukaryotes? - ANS -Organisms made of eukaryotic cells
What is a prokaryote? - ANS -A prokaryotic cell (it's a single celled organism)
What is cytoplasm? - ANS -A liquid gel in which most of the chemical reactions needed for life
take place. It contains enzymes that control these chemical reactions
In what types of cells is cytoplasm found? - ANS -Animal, plant, algae, and bacteria cells
What is the cell membrane? - ANS -It holds the cell together and controls the passage of
substances in and out of the cell
In what types of cells is a cell membrane found? - ANS -Animal, plant, algae, and bacteria cells
What is the nucleus? - ANS -It carries the instructions for making new cells or organisms and
controls all activities of the cell
In what types of cell is a nucleus found? - ANS -Animal, plant, and algae cells
What is the cell wall? - ANS -It is made of cellulose in plants and peptidoglycan in bacteria. It
strengthens and supports the cell.
In what types of cell is a cell wall found? - ANS -Plant, and bacteria cells
What are chloroplasts? - ANS -They are found in the green parts of a plant, and they contain
chlorophyll which allows the cell to create food and light energy
In what types of cell are chloroplasts found? - ANS -Plant, and algae cells
What are ribosomes? - ANS -They are the site of protein synthesis. All the proteins needed in
the cell are made here. The ribosomes are attached to the RER (rough endoplasmic reticulum)
In what types of cell are ribosomes found? - ANS -Animal, and plant cells
,What are mitochondria? - ANS -They are structures in the cytoplasm. Oxygen is used, and
energy is released during respiration here
In what types of cell are mitochondria found? - ANS -Animal, plant, and algae cells
What is a permanent vacuole? - ANS -It is a space in the cytoplasm filled with cell sap. It is
important for keeping the cell rigid to support the plant
In what types of cell is a permanent vacuole found? - ANS -Plant, and algae cells
What is a plasmid? - ANS -A small, circular piece of DNA that carries genes additional to those
in the main genetic material
What two features do bacteria cells NOT have? - ANS -Chloroplasts and mitochondria
How do light microscopes work? - ANS -They use light and lenses to form an image of a
specimen and magnify it
What can we see using a microscope? - ANS -Individual cells and large sub-cellular structures,
like nuclei
What do electron microscopes use to form an image? - ANS -Electrons
Out of electron and light microscopes, which has a higher resolution? - ANS -Electron
microscopes
What can we see with electron microscopes? - ANS -The internal structure of mitochondria and
chloroplasts, ribosomes, and plasmids
What is the formula for magnification? - ANS -Magnification is image size divided by real size
How do you convert from micrometres into millimetres? - ANS -Divide by 1000
What is a flagellum for? - ANS -Locomotion
In what type of cell is a flagellum found? - ANS -Bacteria
What are nerve cells specialised to do? - ANS -Carry impulses around an organism. They
provide a quick communication system
What are four adaptations of nerve cells? - ANS -Lots of dendrites to connect with other cells
Axon that carries nerve impulses from one place to another
Synapses adapted to pass impulses on using transmitter chemicals
,Long so they cover more distance
What is differentiation? - ANS -The process where a cell changes to become specialised
What are stem cells? - ANS -Undifferentiated cells
What are sperm cells specialised to do? - ANS -Get the male DNA to the female DNA by
fertilising an egg
What are three adaptations of sperm cells? - ANS -Long tail to help it swim
Lots of mitochondria to provide the energy needed for the sperm cell to move
Digestive enzymes in the head to digest the egg cell membrane
What are muscle cells specialised to do? - ANS -Contract and relax to move the bones of the
skeleton
What are two adaptations of muscle cells? - ANS -Long so they have space to contract
Contain lots of mitochondria to generate the energy needed for contraction
What are root hair cells specialised to do? - ANS -Absorb water and minerals
What is one adaptation of a root hair cell? - ANS -Large surface area for absorbing water and
mineral ions from the soil
What are photosynthetic cells specialised to do? - ANS -Carry out photosynthesis
What are three adaptations of photosynthetic cells? - ANS -Contain chloroplasts, which contain
chlorophyll for photosynthesis
Positioned in continuous layers in the leaves and outer layers of the stem of a plant to help
absorb light
Have a large permanent vacuole to keep the cell rigid
What are xylem cells specialised to do? - ANS -Carry water and mineral ions from the roots to
the highest leaves and shoots
What are two adaptations of xylem cells? - ANS -Xylem cells are alive when they are first
formed, but die and form hollow tubes for the water and mineral ions to pass through
They have rings of lignin to help withstand the pressure of water in the plant
What are phloem cells specialised to do? - ANS -Carry food around the plant (translocation)
What are two adaptations of phloem cells? - ANS -The cell walls between the cells break down
and form sieve plates which allow water and dissolved food to move as needed.
They are supported by the companion cells that transfer the energy needed to move the food.
, Where are stem cells found in adults? - ANS -Bone marrow
What is the difference between embryonic stem cells and adult stem cells? - ANS -Adult stem
cells can only turn into certain cell types, like blood cells, whereas embryonic stem cells can turn
into any type of cells
How can adult stem cells be used to cure disease? - ANS -Stem cells transferred from the bone
marrow of a healthy person can replace faulty blood cells in the patient who receives them
How can embryonic stem cells be used? - ANS -Make insulin-producing cells for diabetics
Nerve cells for people paralysed by spinal injuries
What is therapeutic cloning? - ANS -The embryo could be made to have the same genetic
information as the patient, meaning the stem cells produced wouldn't be rejected by the patient's
body as the genes are the same.
What is a risk of using stem cells in medicine? - ANS -Stem cells may get contaminated with a
virus, which could be passed on to the patient, making them sicker
Give one argument against using stem cell research - ANS -Each one is a potential human life
Give one argument for using stem cell research - ANS -Curing patients who are suffering is
more important than the rights of embryos
How can stem cells be used for plants? - ANS -Produce clones quickly and cheaply
Grow more plants of rare species
Grow crops that have desired features (e.g. disease resistance)
What are chromosomes? - ANS -Coiled up lengths of DNA molecules
How many copies of each chromosome does a body cell normally have? - ANS -Two - one from
each parent
How many pairs of chromosomes does a human cell have? - ANS -23
What is mitosis? - ANS -Division of cells
What do multicellular organisms use mitosis for? - ANS -Growth, or to replace cells that have
been damaged
What do cells do before they divide? - ANS -Increase their sub-cellular structures, like
mitochondria and ribosomes
