OCR A LEVEL BIOLOGY YEAR 1 (AS) Ouestions And Answers
2025\2026
What is the maximum resolution of a light microscope? - CORRECT ANSWER-200
nm
what is the maximum resolution of an electron microscope - CORRECT ANSWER-
scanning 3-10 nm
tranmission 0.2 nm
What is the maximum magnification of a light microscope - CORRECT ANSWER-
x1500
what is the max magnification of an electron microscope? - CORRECT ANSWER-
SEM x200000
TEM x500000
light microscope advantages - CORRECT ANSWER-use living specimens
see in colour
cheap
easy to use
,portable
light microscope disadvantages - CORRECT ANSWER-low magnification and
resolution
electron microscope advantages - CORRECT ANSWER-high magnification and
resolution
can see specimens in detail
SEM - produce a 3D image
electron microscope disadvantages - CORRECT ANSWER-use non living specimens
greyscale image
expensive
hard to use - need training
non portable
Magnification formula - CORRECT ANSWER-Image size / actual size
Whats resolution? - CORRECT ANSWER-degree of clarity to which you can
distinguish between two different objects
what is magnification? - CORRECT ANSWER-how many times larger the image size
is compared to the actual size
,Differential staining - CORRECT ANSWER-use of a specific stain to differentiate
between different organelles and cell structures which would other wise be hard
to identify
Stain cell components - CORRECT ANSWER-methylene blue or crystal violet
Stain cell cytoplasm - CORRECT ANSWER-congo red or nigrosin
Prokaryotic cell - CORRECT ANSWER-have no membrane bound organelles so they
don't have a nucleus so DNA is a naked loop and they have smaller 70s ribosomes
eukaryotic cell - CORRECT ANSWER-has membrane bound organelles where DNA
is wound around histone proteins into chromosomes and is located in the nucleus
and they have larger 80s ribosomes
microfilament in cytoskeleton - CORRECT ANSWER-has contractile actin fibres for
cell movement and contraction in cytokinesis
microtubules in cytoskeleton - CORRECT ANSWER-globular proteins polymerised
into tubes to determine cell shape and make tracks for cell movement by motor
proteins and they form spindle fibres
intermediate fibres in cytoskeleton - CORRECT ANSWER-for mechanical strength
and to help maintain cell integrity
, Nucleus - CORRECT ANSWER-consists of nucleolus where the genetic information
is stored
and the nuclear envelope which has nuclear pores to control what enters and
leaves the cell
Rough Endoplasmic Reticulum (RER) - CORRECT ANSWER-has ribosomes to
synthesise proteins into their primary structure
Smooth Endoplasmic reticulum (SER) - CORRECT ANSWER-no ribosomes, for lipid
and carbohydrate synthesis and storage
Golgi apparatus - CORRECT ANSWER-processed proteins into their final 3D shape
where they are packaged into vesicles for storage and transport
Ribosomes - CORRECT ANSWER-synthesis of proteins
mitochondria - CORRECT ANSWER-site of aerobic respiration where ATP is
produced
Lysosomes - CORRECT ANSWER-vesicle containing hydrolytic enzymes to digest
and break down material
chloroplasts - CORRECT ANSWER-site of photosynthesis has chlorophyll in the
stroma to absorb light
flagella and cillia - CORRECT ANSWER-are to aid cell movement
2025\2026
What is the maximum resolution of a light microscope? - CORRECT ANSWER-200
nm
what is the maximum resolution of an electron microscope - CORRECT ANSWER-
scanning 3-10 nm
tranmission 0.2 nm
What is the maximum magnification of a light microscope - CORRECT ANSWER-
x1500
what is the max magnification of an electron microscope? - CORRECT ANSWER-
SEM x200000
TEM x500000
light microscope advantages - CORRECT ANSWER-use living specimens
see in colour
cheap
easy to use
,portable
light microscope disadvantages - CORRECT ANSWER-low magnification and
resolution
electron microscope advantages - CORRECT ANSWER-high magnification and
resolution
can see specimens in detail
SEM - produce a 3D image
electron microscope disadvantages - CORRECT ANSWER-use non living specimens
greyscale image
expensive
hard to use - need training
non portable
Magnification formula - CORRECT ANSWER-Image size / actual size
Whats resolution? - CORRECT ANSWER-degree of clarity to which you can
distinguish between two different objects
what is magnification? - CORRECT ANSWER-how many times larger the image size
is compared to the actual size
,Differential staining - CORRECT ANSWER-use of a specific stain to differentiate
between different organelles and cell structures which would other wise be hard
to identify
Stain cell components - CORRECT ANSWER-methylene blue or crystal violet
Stain cell cytoplasm - CORRECT ANSWER-congo red or nigrosin
Prokaryotic cell - CORRECT ANSWER-have no membrane bound organelles so they
don't have a nucleus so DNA is a naked loop and they have smaller 70s ribosomes
eukaryotic cell - CORRECT ANSWER-has membrane bound organelles where DNA
is wound around histone proteins into chromosomes and is located in the nucleus
and they have larger 80s ribosomes
microfilament in cytoskeleton - CORRECT ANSWER-has contractile actin fibres for
cell movement and contraction in cytokinesis
microtubules in cytoskeleton - CORRECT ANSWER-globular proteins polymerised
into tubes to determine cell shape and make tracks for cell movement by motor
proteins and they form spindle fibres
intermediate fibres in cytoskeleton - CORRECT ANSWER-for mechanical strength
and to help maintain cell integrity
, Nucleus - CORRECT ANSWER-consists of nucleolus where the genetic information
is stored
and the nuclear envelope which has nuclear pores to control what enters and
leaves the cell
Rough Endoplasmic Reticulum (RER) - CORRECT ANSWER-has ribosomes to
synthesise proteins into their primary structure
Smooth Endoplasmic reticulum (SER) - CORRECT ANSWER-no ribosomes, for lipid
and carbohydrate synthesis and storage
Golgi apparatus - CORRECT ANSWER-processed proteins into their final 3D shape
where they are packaged into vesicles for storage and transport
Ribosomes - CORRECT ANSWER-synthesis of proteins
mitochondria - CORRECT ANSWER-site of aerobic respiration where ATP is
produced
Lysosomes - CORRECT ANSWER-vesicle containing hydrolytic enzymes to digest
and break down material
chloroplasts - CORRECT ANSWER-site of photosynthesis has chlorophyll in the
stroma to absorb light
flagella and cillia - CORRECT ANSWER-are to aid cell movement
