OCR a level biology foundations Questions And Answers.
Staining - answer;-Allows specimen to become more visible to see certain (named)
organelles and improve contrast
methylene blue - answer;-All purpose
Eosin - answer;-cytoplasm, pink
Acetic orcein - answer;-stains DNA dark red
Sudan - answer;-lipids
Iodine - answer;-plasma membrane
light microscope: magnification and resolution - answer;-1500x and 200nm
Transmission electron microscope - answer;-2,000,000 x magnification
0.5 nm resolution
2D image
Electrons go through specimen
Scanning electron microscope - answer;-200,000 x magnification
3-10nm resolution
3D image
Electrons bounce off specimen
Laser scanning confocal microscopes - answer;-Sample treated with fluorescent dye,
laser focuses on this allowing dye to be seen. High resolution
used in diagnostics e.g. eye problem's
Preparation of sample for magnification - answer;-Stain it
ensure it is thin enough so light can pass through
place on microscope slide at one end
use second slide to spread sample
place cover slips on at an angle
Scientific drawings - answer;-Over 1/2 of page
clear, correct lines
correct proportions
labels with ruled lines, not crossing over
annotations
scale
title
flagella - answer;-9,2 microtubule arrangement
rotate to allow cell to move
, OCR a level biology foundations Questions And Answers.
Interrelationship of organelles in making proteins - answer;-Uncles site of transcription,
makes mRNA, leaves via pores
ribosomes: translation occurs
vesicles to RER: folded into tertiary structure
vesicles to Golgi apparatus: modified by addition of sugars
vesciles to plasma membrane: exocytosis occurs
mitochondria: ATP for exocytosis
Cytoskeleton: structure - answer;-microfilaments, microtubules, intermediate filaments
Cytoskeleton: function - answer;-Change cell shape (microfilaments)
movement of organelles and chromosomes (microtubule)
whole cell support (intermediate filament)
movement of cilia and flagella
Comparing Prokaryotic and Eukaryotic Cells - answer;-Eukaryotes 10-100 um,
prokaryotes 1-10 um
cellulose vs peptidoglycan cell wall
both have ribosomes, DNA and plasma membrane
prokaryotes do not have a nucleus eukaryotes do
eukaryotes have mitochondria prokaryotes have mesome
prokaryotes do not have membrane bound organelles
Roles of plasma membranes: partially permeable - answer;-Allow transfer of substances
in and out of cell
Roles of plasma membranes: compartmentalisation - answer;-In lysosomes, hydrolitic
enzymes need to be separate from other organelles
separates from cytoplasm
Roles of plasma membranes: communication - answer;-Glyolipids and glycoproteins
have specific receptors to detect chemical signals e.g. hormones
allows for cell signalling and cell recognition
Fluid mosaic model - answer;-Describes structure of phospholipid bilayer as very
flexible and has proteins and glycoproteins in it giving it a mosaic arrangement
Effect of alcohols and detergents of fluidity of membrane - answer;-Dissolves
phospholipids causing membrane to become more fluid
Diffusion - answer;-net movement of particles from an area of higher concentration to an
area of lower concentration down a concentration gradient. Passive, does not require
ATP
Staining - answer;-Allows specimen to become more visible to see certain (named)
organelles and improve contrast
methylene blue - answer;-All purpose
Eosin - answer;-cytoplasm, pink
Acetic orcein - answer;-stains DNA dark red
Sudan - answer;-lipids
Iodine - answer;-plasma membrane
light microscope: magnification and resolution - answer;-1500x and 200nm
Transmission electron microscope - answer;-2,000,000 x magnification
0.5 nm resolution
2D image
Electrons go through specimen
Scanning electron microscope - answer;-200,000 x magnification
3-10nm resolution
3D image
Electrons bounce off specimen
Laser scanning confocal microscopes - answer;-Sample treated with fluorescent dye,
laser focuses on this allowing dye to be seen. High resolution
used in diagnostics e.g. eye problem's
Preparation of sample for magnification - answer;-Stain it
ensure it is thin enough so light can pass through
place on microscope slide at one end
use second slide to spread sample
place cover slips on at an angle
Scientific drawings - answer;-Over 1/2 of page
clear, correct lines
correct proportions
labels with ruled lines, not crossing over
annotations
scale
title
flagella - answer;-9,2 microtubule arrangement
rotate to allow cell to move
, OCR a level biology foundations Questions And Answers.
Interrelationship of organelles in making proteins - answer;-Uncles site of transcription,
makes mRNA, leaves via pores
ribosomes: translation occurs
vesicles to RER: folded into tertiary structure
vesicles to Golgi apparatus: modified by addition of sugars
vesciles to plasma membrane: exocytosis occurs
mitochondria: ATP for exocytosis
Cytoskeleton: structure - answer;-microfilaments, microtubules, intermediate filaments
Cytoskeleton: function - answer;-Change cell shape (microfilaments)
movement of organelles and chromosomes (microtubule)
whole cell support (intermediate filament)
movement of cilia and flagella
Comparing Prokaryotic and Eukaryotic Cells - answer;-Eukaryotes 10-100 um,
prokaryotes 1-10 um
cellulose vs peptidoglycan cell wall
both have ribosomes, DNA and plasma membrane
prokaryotes do not have a nucleus eukaryotes do
eukaryotes have mitochondria prokaryotes have mesome
prokaryotes do not have membrane bound organelles
Roles of plasma membranes: partially permeable - answer;-Allow transfer of substances
in and out of cell
Roles of plasma membranes: compartmentalisation - answer;-In lysosomes, hydrolitic
enzymes need to be separate from other organelles
separates from cytoplasm
Roles of plasma membranes: communication - answer;-Glyolipids and glycoproteins
have specific receptors to detect chemical signals e.g. hormones
allows for cell signalling and cell recognition
Fluid mosaic model - answer;-Describes structure of phospholipid bilayer as very
flexible and has proteins and glycoproteins in it giving it a mosaic arrangement
Effect of alcohols and detergents of fluidity of membrane - answer;-Dissolves
phospholipids causing membrane to become more fluid
Diffusion - answer;-net movement of particles from an area of higher concentration to an
area of lower concentration down a concentration gradient. Passive, does not require
ATP
