B1 Cells And Organisation X Microscope Flashcards
What is diffusion?
The movement of particles from high concentration to low conventration
What is the difference in concentration called?
Concentration gradiant (the bigger the concentration gradient the faster the diffusion rate)
Where does diffusion happen?
In solutions and gasses
What part of the cell lets stuff diffuse in and out of the cell
Cell membrane
What temperature creates a higher diffusion rate
Hotter
What is osmosis?
The movement of liquid from a high concentration to a low concentration
What does low and high concentration mean in liquid?
Low= more particles
High= less particles
Why does osmosis happen?
Because the liquid is trying to even up
What are the two things cells can be?
Prokaryotic and eukaryotic
Define the word tissue
Collection of cells of similar structure and function allworking together
Define the word organ
Collection of diffrent tissues working together to carry out a specific functiom
What does the digestion system do?
Digestion is the process where the large molecules into small molecules so they can be absorbed into the blood
What is active transport?
The movement of molecules across a cell membrane from a region of lower concentration to high concentration against a gradiant
How do you calculate magnification
Magnification=eyepiece lens x objective lens
What is resolution
The ability to distinguish between two seperate points in an image
What is the function of the nucleus
Contains DNA in the form of chromosones, contains the genetic code.
What is the function of the cytoplasm
Where chemical reactions take place
What is the function of the cell membrane
Controls what comes in and out of the cell
What is the function of mitochondria
This is where respiration takes place
What is the function of the cellulose cell wall
The outside layer of plant cells and gives the plant strength and support
What is the function of ribosomes
The location where proteins are made
What is the function of chloropasts
Contains a chemical called chlorophyll. It traps sunlight energy which is needed for photosynthesis
What happens to an animal cell when placed in a more dilute solution
The cell gains water through osmosis and it may burst
What happens to an animal cell when placed in a more concentrated solution
The cell loses water and may shrivel
What happens to a plant cell when placed in a more dilute solution
Gains water through osmosis however doesnt burst
Why does a plant cell not burst when placed in a more dilute solution
The plant cell has a cell wall
What happens to a plant cell when placed in a more concentrated solution
Loses water by osmosis and the cell membrane pulls away from the cell wall
What types of cells dont have a nucleus
Prokaryotic cells
What is the function of sperm cells
They fertilise the egg cell during sexual reproduction
What is the function of nerve cells
Transmits electrical pulses around the body
What is the function of muscle cells
Are specialised to contract quickly to move bones
What is the function of root hair cells in plants
Specialised to absorb water by osmosis and mineral ions by active transport
How do you calculate mm to nm
X1000
Convert 20mm to nm
20mm x 1000=20,000nm
What are the 8 main parts of the light microscope
Eyepiece lens, body tube, high and low power objective lenses, stage, mirror, rough focusing knob, fine focusing knob, handle.
What is an organism
A living thing made up of cells
What are 4 things animal and plant cells both have
Nucleus, cytoplasm, cell membrane, mitochondria
What are three things plant cells have than animal cells dont
Cell wall, vacuole, chloropasts.
What are multi cellular organisms
Made up of lots of cells
What are unicellular organisms
Organisms made up of only one cell
what are eukaryotic cells
multi cell organism
what are prokaryotic cells
single cell organism
what are the 5 main things an animal cells contains
nucleus, cytoplasm, cell membrane, mitochondria, ribososmes
what is the main role of the cytoplasm
destination where chemical reactions take place, contains enxymes to control these chemical reactions
what is the main role of the cell membrane
controls what goes in and out of the cell
what is the main role of the mitochondria
where most reactions for aerobic respiration takes place
what is the main role of ribosomes
where proteins are made in the cell
what are the 3 extra things plant cells have that animal cells dont have
rigid cell wall, permanent vacuole, chloropasts
what is the cell wall maded out of in a plant cell
cellulose
what does the cell wall do
suppports and strengthens the cell
what is the main function of the chloropast
where photosynthesis occcurs making food for the plant
whta do chloropasts contain and what is its purpose
chlorophyll, a green substance in the leaf which absorbs the light needed for photosynthesis
what are the three main things that bacterial cells dont contain
chloropasats, mitochndria, nucleus
what holds the dna in a bacterial cell
the plasmid
what are the 4 main things bacterial cells contain
cell membrane, cytoplasm, cell wall and plasmid
what do light microscopes use and allow us to see
use light and lenses to magnify an image and let su see individual cells and large subcellular structures
what do electron microscopes use and allow us to see
use electrons instead of lights and have a great magnification
compare the difference of images a light microscope will show to an electron microscope
electron microscopes have a greater magnification and a higher resolution
how to prepare your slide to view an onion cell
add a drop of water to the middle of a clean slide, cut an onion and peel off a layer using some tweezers. using the tweezers place the epidermal tissue (layer of onion) into the wtare on the slide. then add a drop of iodine solution and place a cover slip on top making sure no air bubbles are underneath.
what is resolution
the ability to distinguish two points under a microscope
why dont you want airbubbles under the cover slip when using a microscope to look at an onion cell
theyll obstruct your view of the specimen onion peel)
how do use a light microscope to look at your slide
clip the slide youve prepared onto the stage, sleect the lwoest powered objective lens, use the coarse adjustment knob to move the stage up to just below the objective lens. look down the eyepiece using the coarse adjustment knob unti you get a clear image
why might you add stain to the sample on a microscope slide
to highlight the object by adding colour to them
what do cells do to become specialized
cells differentiate
what is differentiation
the process by which a cell becomes specialized for its purpose
what allows cells to carry out a specific function
by developing different subcellular structures turning into different types of cells
what are sperm cells spezializeed for
reproduction
what are nerve cells specialised for
rapid signalling
what are muscle cells specialised for
contraction
what are root hair cells specialised for
absorbing water and minerals
what are phloem and xylem cells specialised for
transporting substances
what are 4 features of a sperm cell which helps it for its role
has a long tail, streamlined head to help it swim to the egg. lots of mitochondria to provide energy needed. carries enzymes in its head to digest through the egg cell membrane
what is the main feature of a nerve cell to help it for its role
has many branched connections at the end of the cell to connect to other nerve cells to create a network
what are the TWO main feature of a muscle cell to help it for its function
muscle cells are long so they have more space to contract. have many mitochondria to generate energy needed for contraction
what is the main feature of phloem and xylem cells which help it for its function
xylem cells are hollow in the centre so stuff can flow through them
phloem cells have little subcellular structure so stuff can flow through them