AQA GCSE Biology - Paper 1 Exam
Study Guide Revision Questions With
A Complete Solutions
What does a nucleus do? - ANS It contains genetic material and controls the
activities of the cell
What does cytoplasm do? - ANS It's a gel-like substance where most of the
chemical reactions happen. It contains enzymes that control these chemical
reactions
What does a cell membrane do? - ANS It holds the cell together and controls what
goes in and out
What do mitochondria do? - ANS These are where most of the reactions for aerobic
respiration occur. Respiration transfers energy that the cell needs to work
What do ribosomes do? - ANS This is where protein synthesis takes place - where
proteins are made in the cell
What do cell walls do? - ANS They are made of cellulose and they support and
strengthen the cell
What does a vacuole do? - ANS It contains cell sap and helps maintain the shape of
the cell
What do chloroplasts do? - ANS This is where photosynthesis occurs, which makes
food for the plant. They contain chlorophyll - a green pigment - which absorbs light
needed for photosynthesis
,What do bacterial cells contain? - ANS Cytoplasm, cell membrane, cell wall,
flagella, ribosomes, mitochondria, slime capsule, plasmids (small rings of DNA) and
a single circular strand of DNA that floats freely in the cytoplasm
What do bacterial cells NOT contain? - ANS A nucleus
What is the equation for magnification? - ANS Image size divided by actual size
What is differentiation? - ANS The process by which a cell changes to become
specialised for its job
What are undifferentiated cells called? - ANS Stem cells
What are sperm cells specialised for and how are they specialised? - ANS
Reproduction - they transport the male DNA to the female DNA
-It has a flagella and a streamlined head to help it swim towards the egg
-There are lots of mitochondria in the cell to provide the energy needed
-It carries enzymes in its head to help digest through the egg cell membranes
What are nerve cells specialised for and how are they specialised? - ANS Rapid
signalling - they carry electrical signals from one part of the body to another
-They are long to cover more distance
-They have branched connections at their ends to connect to other nerve cells and
form a network throughout the body
What are muscle cells specialised for and how are they specialised? - ANS
Contraction - they need to contract quickly
-They are long so they have space to contract
-They contain lots of mitochondria to generate the energy needed for contraction
What are root hair cells specialised for and how are they specialised? - ANS
Absorbing water and minerals
-They are cells on the surface of plant roots which grow into long hairs that stick out
into the soil
-They have a large surface area for absorbing water and mineral ions from the soil
What are chromosomes? - ANS Coiled up lengths of DNA molecules that are found
in the nuclei
, What do multicellular organisms use mitosis for? - ANS To grow or replace cells that
have been damaged
What are stem cells? - ANS They are undifferentiated cells that divide to produce
lots more undifferentiated cells. They then differentiate into different types of cell
Where are stem cells found? - ANS In early human embryos or the bone marrow of
adults
What do embryonic stem cells do? - ANS 1) Used to replace faulty cells in sick
people - insulin-producing cells for diabetes and nerve cells for paralysed spinal
injuries
2) Used to replace faulty blood cells
What is diffusion? - ANS Diffusion is the movement of particles from an area of high
concentration to an area of low concentration
Name the substances that can diffuse through cell membranes - ANS Glucose,
water, oxygen and amino acids
Name two substances that can't diffuse through cell membranes - ANS Protein and
starch
What is osmosis? - ANS Osmosis is the passive movement of water molecules
through a partially permeable cell membrane from an area of high water
concentration to an area of low water concentration
What are the two main differences between active transport and diffusion? - ANS
Active transport uses energy whereas diffusion doesn't. Active transport goes
against the concentration gradient whereas diffusion goes along it
Adaptations of Exchange Surfaces - ANS 1) Large surface area - lots of substances
can diffuse at once
2) Lots of blood vessels - to get stuff into and out of the blood quickly
3) Thin membrane - short distance for substances to diffuse
4) Often ventilated - air moves in & out
Give two ways that the villi in the small intestine are adapted for absorbing digested
food - ANS 1) A single layer of surface cells
2) A very good blood supply to assist quick absorption
Study Guide Revision Questions With
A Complete Solutions
What does a nucleus do? - ANS It contains genetic material and controls the
activities of the cell
What does cytoplasm do? - ANS It's a gel-like substance where most of the
chemical reactions happen. It contains enzymes that control these chemical
reactions
What does a cell membrane do? - ANS It holds the cell together and controls what
goes in and out
What do mitochondria do? - ANS These are where most of the reactions for aerobic
respiration occur. Respiration transfers energy that the cell needs to work
What do ribosomes do? - ANS This is where protein synthesis takes place - where
proteins are made in the cell
What do cell walls do? - ANS They are made of cellulose and they support and
strengthen the cell
What does a vacuole do? - ANS It contains cell sap and helps maintain the shape of
the cell
What do chloroplasts do? - ANS This is where photosynthesis occurs, which makes
food for the plant. They contain chlorophyll - a green pigment - which absorbs light
needed for photosynthesis
,What do bacterial cells contain? - ANS Cytoplasm, cell membrane, cell wall,
flagella, ribosomes, mitochondria, slime capsule, plasmids (small rings of DNA) and
a single circular strand of DNA that floats freely in the cytoplasm
What do bacterial cells NOT contain? - ANS A nucleus
What is the equation for magnification? - ANS Image size divided by actual size
What is differentiation? - ANS The process by which a cell changes to become
specialised for its job
What are undifferentiated cells called? - ANS Stem cells
What are sperm cells specialised for and how are they specialised? - ANS
Reproduction - they transport the male DNA to the female DNA
-It has a flagella and a streamlined head to help it swim towards the egg
-There are lots of mitochondria in the cell to provide the energy needed
-It carries enzymes in its head to help digest through the egg cell membranes
What are nerve cells specialised for and how are they specialised? - ANS Rapid
signalling - they carry electrical signals from one part of the body to another
-They are long to cover more distance
-They have branched connections at their ends to connect to other nerve cells and
form a network throughout the body
What are muscle cells specialised for and how are they specialised? - ANS
Contraction - they need to contract quickly
-They are long so they have space to contract
-They contain lots of mitochondria to generate the energy needed for contraction
What are root hair cells specialised for and how are they specialised? - ANS
Absorbing water and minerals
-They are cells on the surface of plant roots which grow into long hairs that stick out
into the soil
-They have a large surface area for absorbing water and mineral ions from the soil
What are chromosomes? - ANS Coiled up lengths of DNA molecules that are found
in the nuclei
, What do multicellular organisms use mitosis for? - ANS To grow or replace cells that
have been damaged
What are stem cells? - ANS They are undifferentiated cells that divide to produce
lots more undifferentiated cells. They then differentiate into different types of cell
Where are stem cells found? - ANS In early human embryos or the bone marrow of
adults
What do embryonic stem cells do? - ANS 1) Used to replace faulty cells in sick
people - insulin-producing cells for diabetes and nerve cells for paralysed spinal
injuries
2) Used to replace faulty blood cells
What is diffusion? - ANS Diffusion is the movement of particles from an area of high
concentration to an area of low concentration
Name the substances that can diffuse through cell membranes - ANS Glucose,
water, oxygen and amino acids
Name two substances that can't diffuse through cell membranes - ANS Protein and
starch
What is osmosis? - ANS Osmosis is the passive movement of water molecules
through a partially permeable cell membrane from an area of high water
concentration to an area of low water concentration
What are the two main differences between active transport and diffusion? - ANS
Active transport uses energy whereas diffusion doesn't. Active transport goes
against the concentration gradient whereas diffusion goes along it
Adaptations of Exchange Surfaces - ANS 1) Large surface area - lots of substances
can diffuse at once
2) Lots of blood vessels - to get stuff into and out of the blood quickly
3) Thin membrane - short distance for substances to diffuse
4) Often ventilated - air moves in & out
Give two ways that the villi in the small intestine are adapted for absorbing digested
food - ANS 1) A single layer of surface cells
2) A very good blood supply to assist quick absorption
