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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?

Cell membranes


What sub cellular organelles are found in a plant cell?

All of the animal cell structures plus:
Rigid cell wall
Permanent Vacuole


What sub cellular organelles are found in a prokaryotic (bacteria) cell

Cell membrane
Cell wall
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


Define 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


Why are people against stem cell research?

because they feel that the embryos from where they are grown from are a waste of a potential human life, but some think the people who are suffering and living with them are more important than the rights of the embryos
Some countries have banned stem cell research.