B1 Cells And Organisation Flashcards
Total magnification =
Eyepiece lens magnification x objective lens magnification
Main parts of animal cell
Nucleus
Cytoplasm
Cell membrane
Mitochondria
Ribosomes
Main parts of plant cell
Nucleus
Cytoplasm
Cell membrane
Cell wall - provides strength and support
Chloroplasts
Vacuole
Mitochondria
Ribosomes
How to prepare a microscope slide
Place a thin sample of the specimen on a slide
Add a drop of stain if necessary to enhance contrast
Carefully place a cover slip over the specimen to avoid air bubbles
Gently press down to spread the sample evenly
Magnification
Ability to make small objects seem larger
Resolution
Ability to distinguish two objects from each other
Difference between light and electron microscope
Electron has high magnification up to 1,000,000x and high resolving power
Similarities between electron and light microscope
Images can be formed from the radiation that is transmitted through the specimen
Use of electron microscope
To investigate cells even further
How to work out magnification
Size of image/size of real object
Disadvantages of electron microscopes
Live cells cannot be imaged as samples must be placed under vacuum
Only black and white image produced
Disadvantages of light microscope
At a certain size image becomes blurry
Limited resolution
Advantages of electron microscopes
Extremely good magnification
Higher resolution
Advantages of light microscopes
Easy to use
Allows you to view live samples of specimen
Cell membrane
Controls the movement of substances in and out of the cell
Which part of a cell is the powerhouse of a cell
Mitochondria
Vacuole
Stores water
Ribosomes
Where proteins are made
Cell wall
Provide structure and protection
Why some cells do not contain all cell structures
Cells are specialized to perform specific functions
Compare plant and animal cells
Plant cells have a cell wall and membrane
Animal cells only have a cell membrane
What microscope is used to see algae
Compound microscope
How to prepare for microscope slide
Place specimen on slide
Apply drop of water
Gently lower a coverslip over the specimen
Prokaryotic cell
A simple cell that does not have a nucleus
Eukaryotic cell
Complex cells that contain a nucleus and other membrane-bound organelles
Unicellular cell
Organisms made up of only one cell
Sub-cellular
Structures are smaller parts that make up a cell
Example of prokayotic cells
Bacteria
Examples of eukaryotic cells
Animal
Plant
Fungi
What are prokrayotic cell walls made up of
Peptidoglycan
Do prokayrotic or eukaryotic cells contain a membrane bound nucleus
Eukaryotic
Differences between prokaryotic and eukaryotic cells
Prokaryotic cells are smaller, have fewer sub-cellular
structures and divide by binary fission
Eukaryotic cells are bigger, have more sub-cellular
structures and divide by mitosis
Similarities between prokaryotic and eukaryotic cells
Cell membrane
DNA
Ability to divide and reproduce
Permanent vacuole
Contains cell sap (weak solution of sugar and salts
Chloroplasts
Where photosynthesis occurs
Chlorophyll
Absorbs light needed for photosynthesis
Plasmids
Small rings of DNA
Plasmids function
Can replicate and move between cells so that genetic information can be shared
What parts of a cell does bacteria not have
Chloroplasts
Mitochondria
How to use a light microscope
Steps 1-3
Clip the slide you’ve prepared onto stage
Select lowest powered objective lens
Use coarse adjustment knob to move stage up
How to use a light microscope
Steps 4-6
Look down eyepiece. Use coarse adjustment knob until get clear image of what’s on slide
Adjust the focus with fine adjustment knob until get clear image
Why animals have specialised cells
To carry out a particular role in the body
Specialised cells
Cells designed to carry out a particular role in the body
How structure of specialised cells related to their function within the organism
Their structure is adapted to their function
Compare the structure of a specialised and generalised animal cell
Generalised cells have simple strcture and can perform basic functions
Specialised cells have complex strtxures and perform specific functions
What determines the function of a specialized cells
The active genes in the cell
How to suggest the function of an unknown
specialised cell based on its structure
Examine cell shape
Elongated cells could have a role in movement or contraction
Flattened cells may suggest covering or protective role
How are animal cells adapted
Specialised cells are adapted to specific functions and so are more efficient in carrying them out
How do prokaryotic cells replicate/divide
Binary fission
How does binary fission (when cell splits in two) work
The circular DNA and plasmids replicate
Cell gets bigger and circular DNA moves to opposite poles
Cytoplasm begins to divide and new cell walla begin to form
Cytoplasm divides and two daughter cells produced
Each daughter cell has 1 copy of circular DNA
Structure of specialised cell
A flat disc shape with dips on both sides (biconcave)
Features of specialised cell
Cell membrane
Cytoplasm
Mitochondria
Haploid nucleus
Function of villi
They increase surface area in a big way so digested food is absorbed more quickly into the blood
How many villi are in small intestine
Millions
How does carbon dioxide diffuse within the leaf
Diffuses into the air spaces wihtin the leaf
How does shape of leaf increase exchange surface
Flattened shape increase area of exchange surface
Features of lamellae which increases surface area
Lots of blood capillaries to speed up diffusion
Thin surface layer
What are Prokaryotic cells are made up of
Peptidoglycan
Eukaryotic cell wall made up of
Cellulose
How do eukaryotic cells divide
Mitosis and meosis