Cell Level Systems Flashcards
Magnification
How much larger a displayed image is compared with the original object
Resolution
The ability to distinguish between two points
Why is staining used
- Some specimens are colourless
- It is useful to highlight different structures
- It increases contrast
What is the formula to calculate magnification from image size and actual size?
What is the formula to calculate magnification from image size and actual size?
(The I AM formula)
Image size = Actual Size x Magnification
Total magnification
Total magnification =
Eyepiece magnification x Objective lens
magnification
Light microscope
Place the specimen on a slide, cover it with a cover slip, illuminate with a lamp and view using the eyepiece
Parts of animal cell
Nucleus, cytoplasm, mitochondria, ribosomes and the cell membrane
Give 3 differences between prokaryotic and eukaryotic cells
- Prokaryotic cells have no nucleus
- Prokaryotic cells have plasmid loops of
DNA - Prokaryotic cells have no mitochondria
Chloroplasts
Site of photosynthesis
Vacuole
Supports the cell, contains cell sap
State 3 organelles in eukaryotic cells only found in plant cells
- Cellulose cell wall
- Permanent vacuole
- Chloroplasts
What is cell wall in bacteria made up of
Peptidoglycan
Advantages of using TEM
Very high resolution
Very high magnification
Can see objects up to 2nm apart
Disadvantages of using TEM
Very expensive
Need to be serviced
Images in black and white
Advantages if using SEM
Faster than TEM
Can have a thicker sample
Less expensive than TEM
Disadvantages of SEM
Lower resolution than TEM
Lower Magnification that TEM
Produces a 3D image which is harder to interpret
What structures are found in both plant and animal cells
Nucleus
Cytoplasm
Cell membrane
Mitochondria
What structures are only found in plant cells
Cell wall
Permanent vacuole
Chloroplasts
What are multicellular organisms
They are organisms that are made up of more than one cell, eg humans
What are unicellular organisms?
They are organism that only contain one cell
How do unicellular organisms survive
They have many adaptations
- flagellum
- pili
- slime capsule
- a small loop of dna (different from the bacterial dna in the cytoplam) is stored in the plasmid. It also contains different adaptations that it can give to the organism during times of chemical or osmotic stress
How are things organised
Cells ——> tissue ——> organ ——> organ system
Nucleus
Contains the genetic material that codes for the function of the cell
Cell wall
A structure made of a rigid material named cellulose and surrounds the cell to help provide support to it
Chloroplasts
Absorb The Sunlight needed to fuel photosynthesis and are found only implants
Flagellum
A small tail like structure found on the outside of the cells that help propel this cell through liquids
What is the function of the Pili
Small hair like structures found on the outside of the cell and allow it to attach to different sub cellular structures of other cells and for genetic information to be passed too and from the cell
Mitochondria
Mitochondria are small sub cellular structures where cellular respiration takes place. Special protein molecules (enzymes) enable glucose and oxygen to react, this reaction transfers energy to the organism.
Cell membrane
The cell wall is a large from selective barrier that is used to control what substances entered out of the cells. It is found in both prokaryotes and eukaryotes
Plasmid
A small ring of DNA that contains the genetic information and is found only in prokaryotic cells. Can also give the cells special abilities that can be used in times of osmotic stress.
Slime capsule
Slime capsules are found on the side of the cell membrane and are used to protect the cell from poisonous substances and helps stop the cell from drying out
What do plant cells and prokaryotes both have that animal cells don’t
A cell wall
Can both prokaryotic and eukaryotic cells have a flagella and pili
Yes, both types of cells have have flagella’s and pilis
What is the two differences between plant and prokaryotic cells
Plant has dna in nucleus and has chloroplasts
Prokaryotes do not have chloroplasts and instead of a nucleus their DNA floats in the cytoplasm
Do both prokaryotes and eukaryotes contain ribosomes?
Yes
