Flashcards in Cell Biology Deck (34):
What are the two types of cell called?
Prokaryotes and eukaryotes
What is a eukaryotic cell
They are more complex and include all animal and plant cells, found in multi cellular organisms
What is a prokaryotic cell
It’s is a smaller and simpler cell, and only found in single celles organisms
What sub cellular organelles are in an animal cell?
What sub cellular organelles are found in a plant cell?
All of the animal cell structures plus:
Rigid cell wall
What sub cellular organelles are found in a prokaryotic (bacteria) cell
Single strand of DNA(floats freely in cytoplasm)
Can also contain more smaller rings of DNA called plasmids
What does a nucleus do?
Contains genetic material that controls activities of the cell
What does the cytoplasm do
It’s a gel like substance that allows most of the chemical reactions to happen inside he cell, also contains enzymes that control the chemical reactions
What does the cell membrane do inside of a cell
All it does is hold the cell together and controls what can come in or out of the cell
What does the mitochondria do inside of the cell
These are where most of the reactions for aerobic respiration happen. Respiration transfers energy that the cells need to work
What do the ribosomes do I side of the cell
These make proteins inside the cell
What does the rigid cell wall do Inside of a plant cell
It’s job is to support the cell and strengthen it, and is made of cellulose
What does the permanent vacuole do inside of a plant cell
It contains the cell sap, weak solution of salts and sugar
Chloroplasts do inside of a plant cell?
This is where the photosynthesis occurs inside of the cell which makes food for the plant. They contain a green substance called chlorophyll which absorbs light which is needed for photosynthesis
What does a microscope do?
It allows us to see things that we can’t see with the naked eye
Describe a light microscope
The use light and lenses to form an image of a specimen and magnify it ( make it look bigger), they allow us to see individual cells and some large sub cellular structures like the nuclei
Describe an electron microscope
The use electrons to create an image, they have a much higher magnification than a light microscope. They allow us to see far smaller things in more detail such as the internal structure of a mitochondria and chloroplasts and even smaller things like ribosomes and plasmids. Also have a much higher resolution
The ability to distinguish between two points, so a higher resolution gives a sharper image
What is the equation for magnification?
Magnifaction= image size/real size
How do you prepare a microscopy slide
Add a drop of water in the middle of the slide
Cut up an onion, separate into layers. Use tweezers to peel off some epidermal tissue from the bottom of one of the layers
Put tissue carefully into the water on the slide
Add drop of iodine solution onto tissue
Place cover slip on the specimen, by tilting and placing it gradually on the specimen so no air bubbles occur
How do you use a microscope?
Clip the slide onto the stage
Select the lowest powered objective lens
Use the coarse adjustment knob to move the stage up, just below the the objective lens
Look down on the eye peice, use the adjust men knob then to adjust until in focus roughly
Then further adjust the focus with a fine adjustment knob until the image is clear
If you need the greater magnification swap to a higher powered objective lens and refocus
How do you draw your observations from the microscope?
Use a sharpened pencil
Draw clear unbroken lines
Subcellular structures should be drawn in proportion
Title the magnification of the diagram
Label the important features of the drawing
Define Cell differenttation
It is the process by which a cell changes to become specialised for its job
What process happens when a cell differentiates
they develop different subcellular structures and turn into different types of cells that become adapted for specific jobs
When does cell differentiation occur
Usually at a young stage in most animals afterward they lose this ability. But plants never lose this ability
Why is cell differentiation used in mature animals
They are mainly used for replacing or repairing cells
Name 6 types of specialised cells
sperm cells - reproduction
Nerve cells - rapid signalling
muscle cells - contraction
Root Hair Cells - Absorbing water and minerals
Phloem and Xylem - Transporting substances
What are stem cells?
They are un differentiated cells that can be made into a differentiated cell. Like a blank canvas being made into a painting
Where are stem cells found?
They are usually found in early stage human embryos
Why are stem cells exciting?
Because they offer many new opportunities to doctors and in the field of medicine
How can stem cells be used in medicine?
You could use embryonic stem cells to replace faulty cells in sick people, such as insulin cells for people with diabetes or nerve cells for paralysed people
Why is therapeutic cloning using embryo stem cells useful?
When an embryo is made to have the same genes as the patient so the cells wouldn't be rejected by the body if the faulty cells were replaced
What are the risks with using stem cells in medicine?
They could get infected with a virus and contaminate the patient