Biology OCR A level paper 1 exam
questions & answers
Magnification of light microscope - ANSWERSX1500
Resolution of light microscope - ANSWERS0.2micrometers
Magnification of a scanning electron microscope - ANSWERSX500000
Resolution of scanning electron microscope - ANSWERS0.002 micrometers
Magnification of a transmission electron microscope - ANSWERSX1,000,000
Resolution of a transmission electron microscope - ANSWERS0.0002 micrometers
What can be used as a counterstain - ANSWERSsafranin dye
Magnification - ANSWERSHow many times larger the image is than the actual size of the object
being viewed
Resolution - ANSWERSHow detailed the image is. How well the microscope distinguishes
between 2 points that are close together.
Nucleolus - ANSWERSProduces 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 - ANSWERSMany lipids and proteins
Centrioles - ANSWERSSmall, hollow cylinders made of microtubules
Microfilaments - ANSWERSContractile fibres formed from actin, responsible or cell movement
and contraction during cytokinesis
Microtubules - ANSWERSDetermine shape of cell and act as tracks for the movement of
organelles
Intermediate fibres - ANSWERSGive cell mechanical strength and help maintain their integrity
Vacuoles - ANSWERSMembrane lined sacs containing cell sap. Important in maintenance of
turgor.
Tonoplast - ANSWERSMembrane of vacuole and is selectively permeable
DNA in prokaryotic cells - ANSWERSCircular, proteins fold and condense DNA, one molecule,
chromosome
DNA in eukaryotic cells - ANSWERSLinear, associated with proteins called histones forming
chromatin, multiple chromosomes
Cell wall in prokaryotic cells made from - ANSWERSPeptidoglycan/murein
Call wall in fungi made from - ANSWERSChitin
Flagella in prokaryotic cells - ANSWERSMade of flagellin, arranged in a helix
, Flagella in eukaryotic cells - ANSWERSMade of microtubules, arranged 9+2 formation
Importance of cytoskeleton - ANSWERSProvide mechanical strength, aiding transport within
cells, enabling movement
High latent heat of evaporation - ANSWERSLot of energy used up when water evaporates -
coolant
Biuret test tests for? - ANSWERSProteins
Biuret test method - ANSWERS1. Add few drops of NaOH
2. Add copper sulfate solution
Positive result for biuret test - ANSWERSblue to purple
What does Benedict's test for - ANSWERSreducing sugars (all monosaccharides, glucose, & some
disaccharides, maltose & lactose)
Method for benedicts test - ANSWERSAdd benedicts reagent and heat in water bath
Positive result for benedicts test - ANSWERSblue --> coloured ppt (brick red)
Benedicts test for non-reducing sugars method - ANSWERSbreak down into monosaccharide by
adding dilute HCl & heating in water bath.
Neutralise with sodiumhydrogencarbonate
Carry out benedicts
questions & answers
Magnification of light microscope - ANSWERSX1500
Resolution of light microscope - ANSWERS0.2micrometers
Magnification of a scanning electron microscope - ANSWERSX500000
Resolution of scanning electron microscope - ANSWERS0.002 micrometers
Magnification of a transmission electron microscope - ANSWERSX1,000,000
Resolution of a transmission electron microscope - ANSWERS0.0002 micrometers
What can be used as a counterstain - ANSWERSsafranin dye
Magnification - ANSWERSHow many times larger the image is than the actual size of the object
being viewed
Resolution - ANSWERSHow detailed the image is. How well the microscope distinguishes
between 2 points that are close together.
Nucleolus - ANSWERSProduces 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 - ANSWERSMany lipids and proteins
Centrioles - ANSWERSSmall, hollow cylinders made of microtubules
Microfilaments - ANSWERSContractile fibres formed from actin, responsible or cell movement
and contraction during cytokinesis
Microtubules - ANSWERSDetermine shape of cell and act as tracks for the movement of
organelles
Intermediate fibres - ANSWERSGive cell mechanical strength and help maintain their integrity
Vacuoles - ANSWERSMembrane lined sacs containing cell sap. Important in maintenance of
turgor.
Tonoplast - ANSWERSMembrane of vacuole and is selectively permeable
DNA in prokaryotic cells - ANSWERSCircular, proteins fold and condense DNA, one molecule,
chromosome
DNA in eukaryotic cells - ANSWERSLinear, associated with proteins called histones forming
chromatin, multiple chromosomes
Cell wall in prokaryotic cells made from - ANSWERSPeptidoglycan/murein
Call wall in fungi made from - ANSWERSChitin
Flagella in prokaryotic cells - ANSWERSMade of flagellin, arranged in a helix
, Flagella in eukaryotic cells - ANSWERSMade of microtubules, arranged 9+2 formation
Importance of cytoskeleton - ANSWERSProvide mechanical strength, aiding transport within
cells, enabling movement
High latent heat of evaporation - ANSWERSLot of energy used up when water evaporates -
coolant
Biuret test tests for? - ANSWERSProteins
Biuret test method - ANSWERS1. Add few drops of NaOH
2. Add copper sulfate solution
Positive result for biuret test - ANSWERSblue to purple
What does Benedict's test for - ANSWERSreducing sugars (all monosaccharides, glucose, & some
disaccharides, maltose & lactose)
Method for benedicts test - ANSWERSAdd benedicts reagent and heat in water bath
Positive result for benedicts test - ANSWERSblue --> coloured ppt (brick red)
Benedicts test for non-reducing sugars method - ANSWERSbreak down into monosaccharide by
adding dilute HCl & heating in water bath.
Neutralise with sodiumhydrogencarbonate
Carry out benedicts
