Biology OCR A level paper 1 || with Certified Answers.
Magnification of light microscope correct answers X1500
Resolution of light microscope correct answers 0.2micrometers
Magnification of a scanning electron microscope correct answers X500000
Resolution of scanning electron microscope correct answers 0.002 micrometers
Magnification of a transmission electron microscope correct answers X1,000,000
Resolution of a transmission electron microscope correct answers 0.0002 micrometers
What can be used as a counterstain correct answers safranin dye
Magnification correct answers How many times larger the image is than the actual size of the
object being viewed
Resolution correct answers How detailed the image is. How well the microscope distinguishes
between 2 points that are close together.
Nucleolus correct answers Produces ribosomes. Made of protein and RNA, which is used to
make rRNA, which combines with protein to form ribosome.
What's the plasma membrane made off correct answers Many lipids and proteins
Centrioles correct answers Small, hollow cylinders made of microtubules
,Microfilaments correct answers Contractile fibres formed from actin, responsible or cell
movement and contraction during cytokinesis
Microtubules correct answers Determine shape of cell and act as tracks for the movement of
organelles
Intermediate fibres correct answers Give cell mechanical strength and help maintain their
integrity
Vacuoles correct answers Membrane lined sacs containing cell sap. Important in maintenance of
turgor.
Tonoplast correct answers Membrane of vacuole and is selectively permeable
DNA in prokaryotic cells correct answers Circular, proteins fold and condense DNA, one
molecule, chromosome
DNA in eukaryotic cells correct answers Linear, associated with proteins called histones forming
chromatin, multiple chromosomes
Cell wall in prokaryotic cells made from correct answers Peptidoglycan/murein
Call wall in fungi made from correct answers Chitin
Flagella in prokaryotic cells correct answers Made of flagellin, arranged in a helix
Flagella in eukaryotic cells correct answers Made of microtubules, arranged 9+2 formation
, Importance of cytoskeleton correct answers Provide mechanical strength, aiding transport within
cells, enabling movement
High latent heat of evaporation correct answers Lot of energy used up when water evaporates -
coolant
Biuret test tests for? correct answers Proteins
Biuret test method correct answers 1. Add few drops of NaOH
2. Add copper sulfate solution
Positive result for biuret test correct answers blue to purple
What does Benedict's test for correct answers reducing sugars (all monosaccharides, glucose, &
some disaccharides, maltose & lactose)
Method for benedicts test correct answers Add benedicts reagent and heat in water bath
Positive result for benedicts test correct answers blue --> coloured ppt (brick red)
Benedicts test for non-reducing sugars method correct answers break down into monosaccharide
by adding dilute HCl & heating in water bath.
Neutralise with sodiumhydrogencarbonate
Carry out benedicts
Non reducing sugar example correct answers sucrose
Iodine test tests for? correct answers Starch
Magnification of light microscope correct answers X1500
Resolution of light microscope correct answers 0.2micrometers
Magnification of a scanning electron microscope correct answers X500000
Resolution of scanning electron microscope correct answers 0.002 micrometers
Magnification of a transmission electron microscope correct answers X1,000,000
Resolution of a transmission electron microscope correct answers 0.0002 micrometers
What can be used as a counterstain correct answers safranin dye
Magnification correct answers How many times larger the image is than the actual size of the
object being viewed
Resolution correct answers How detailed the image is. How well the microscope distinguishes
between 2 points that are close together.
Nucleolus correct answers Produces ribosomes. Made of protein and RNA, which is used to
make rRNA, which combines with protein to form ribosome.
What's the plasma membrane made off correct answers Many lipids and proteins
Centrioles correct answers Small, hollow cylinders made of microtubules
,Microfilaments correct answers Contractile fibres formed from actin, responsible or cell
movement and contraction during cytokinesis
Microtubules correct answers Determine shape of cell and act as tracks for the movement of
organelles
Intermediate fibres correct answers Give cell mechanical strength and help maintain their
integrity
Vacuoles correct answers Membrane lined sacs containing cell sap. Important in maintenance of
turgor.
Tonoplast correct answers Membrane of vacuole and is selectively permeable
DNA in prokaryotic cells correct answers Circular, proteins fold and condense DNA, one
molecule, chromosome
DNA in eukaryotic cells correct answers Linear, associated with proteins called histones forming
chromatin, multiple chromosomes
Cell wall in prokaryotic cells made from correct answers Peptidoglycan/murein
Call wall in fungi made from correct answers Chitin
Flagella in prokaryotic cells correct answers Made of flagellin, arranged in a helix
Flagella in eukaryotic cells correct answers Made of microtubules, arranged 9+2 formation
, Importance of cytoskeleton correct answers Provide mechanical strength, aiding transport within
cells, enabling movement
High latent heat of evaporation correct answers Lot of energy used up when water evaporates -
coolant
Biuret test tests for? correct answers Proteins
Biuret test method correct answers 1. Add few drops of NaOH
2. Add copper sulfate solution
Positive result for biuret test correct answers blue to purple
What does Benedict's test for correct answers reducing sugars (all monosaccharides, glucose, &
some disaccharides, maltose & lactose)
Method for benedicts test correct answers Add benedicts reagent and heat in water bath
Positive result for benedicts test correct answers blue --> coloured ppt (brick red)
Benedicts test for non-reducing sugars method correct answers break down into monosaccharide
by adding dilute HCl & heating in water bath.
Neutralise with sodiumhydrogencarbonate
Carry out benedicts
Non reducing sugar example correct answers sucrose
Iodine test tests for? correct answers Starch
