Topic 1 - Cells Flashcards
Name all the features of an animal cell.
- cytoplasm
- nucleus
- mitochondria
- cell membrane
Name all the features of a plant cell.
- cytoplasm
- cellulose cell wall
- cell membrane
- Nucleus
- vacuole
- mitochondria
- chloroplasts
Why is he nucleus called the control centre of the cell ?
It’s surrounded by nuclear membrane and these contain chromosomes. Which then contain DNA.
What’s the purpose of a cellulose cell wall?
Stiff structure, and it provides support
What’s the purpose of the vacuole ?
Contains cell sap, when it’s full it pushes the cell membrane against the cell wall making the cell rigid.
What are the purpose of chloroplasts ?
Contain chlorophyll , which traps light and makes food during photosynthesis.
List the features of a bacterial cell.
- circular chromosome
- plasmid
- non-cellulose cell wall
What are the plasmids in the bacterial cell ?
Small rings of DNA
List the steps taken to prepare a slide to look at onion cells.
1: peel a thin transparent layer of onion off with forceps
2: place on the slide with a few drops of water.
3: add iodine to stain the cells to make them easier to see.
4: lower coverslip over the epidermis( make sure no air bubbles are present)
What is the (did)advantages to using a low power objective lens ?
Advantages:
• greater field of view
• easier to focus
Disadvantages:
• only see a little detail
What are the (dis)advantages of using a high power lens?
Advantages:
•see in greater detail
Disadvantages
• harder to focus
• can be damaged easily
• lower field of view
What’s the equation for magnification?
Observed
——————————-
Actual x magnification
State how to convert mm - um
mm - m
And the standard form of mm and um in m
Multiply um by 1000 to get mm
Multiply mm by 1000 to get m
mm = 10^-3 um = 10^-6
What’s a microscopes resolution ?
The ability of the microscope to let us see detail.
How do electron microscopes work?
Pass a beam of electrons through a specimen, to investigate the structures inside cells.