AQA AS BIOLOGY PAPER 1 STUDY GUIDE 2026
QUESTIONS WITH COMPLETE SOLUTIONS
◉ What does cytoplasm do? Answer: 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? Answer: It holds the cell together
and controls what goes in and out
◉ What do mitochondria do? Answer: These are where most of the
reactions for aerobic respiration occur. Respiration transfers energy
that the cell needs to work
◉ What do ribosomes do? Answer: This is where protein synthesis
takes place - where proteins are made in the cell
◉ What do cell walls do? Answer: They are made of cellulose and
they support and strengthen the cell
◉ What does a vacuole do? Answer: It contains cell sap and helps
maintain the shape of the cell
,◉ What do chloroplasts do? Answer: 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? Answer: 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? Answer: A nucleus
◉ What is the equation for magnification? Answer: Image size
divided by actual size
◉ What is differentiation? Answer: The process by which a cell
changes to become specialised for its job
◉ What are undifferentiated cells called? Answer: Stem cells
◉ What are sperm cells specialised for and how are they
specialised? Answer: 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?
Answer: 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? Answer: 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? Answer: 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? Answer: Coiled up lengths of DNA
molecules that are found in the nuclei
◉ What do multicellular organisms use mitosis for? Answer: To
grow or replace cells that have been damaged
◉ What are stem cells? Answer: 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? Answer: In early human embryos or
the bone marrow of adults
◉ What do embryonic stem cells do? Answer: 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? Answer: 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
Answer: Glucose, water, oxygen and amino acids
QUESTIONS WITH COMPLETE SOLUTIONS
◉ What does cytoplasm do? Answer: 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? Answer: It holds the cell together
and controls what goes in and out
◉ What do mitochondria do? Answer: These are where most of the
reactions for aerobic respiration occur. Respiration transfers energy
that the cell needs to work
◉ What do ribosomes do? Answer: This is where protein synthesis
takes place - where proteins are made in the cell
◉ What do cell walls do? Answer: They are made of cellulose and
they support and strengthen the cell
◉ What does a vacuole do? Answer: It contains cell sap and helps
maintain the shape of the cell
,◉ What do chloroplasts do? Answer: 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? Answer: 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? Answer: A nucleus
◉ What is the equation for magnification? Answer: Image size
divided by actual size
◉ What is differentiation? Answer: The process by which a cell
changes to become specialised for its job
◉ What are undifferentiated cells called? Answer: Stem cells
◉ What are sperm cells specialised for and how are they
specialised? Answer: 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?
Answer: 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? Answer: 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? Answer: 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? Answer: Coiled up lengths of DNA
molecules that are found in the nuclei
◉ What do multicellular organisms use mitosis for? Answer: To
grow or replace cells that have been damaged
◉ What are stem cells? Answer: 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? Answer: In early human embryos or
the bone marrow of adults
◉ What do embryonic stem cells do? Answer: 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? Answer: 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
Answer: Glucose, water, oxygen and amino acids
