Have a cell membrane, cytoplasm and genetic material (DNA) enclosed in a nucleus
Prokaryotic cells

Smaller than eukaryotic cells, the genetic material is not enclosed in a nucleus, the DNA is a single loop and there may be one or more rings of DNA called plasmids
Bacterial cells are prokaryoticcells
Prefixes
centi (cm) 1 cm = 0.01 m
milli (mm) 1 mm = 0.001 m
micro (μm) 1 μm = 0.000 001 m
nano (nm) 1 nm = 0.000 000 001 m
Prefixes are used in science to make very small numbers more manageable. You need to learn the ones in the table and be able to convert to and from standard form.
You will need to know the differences between animal, plant cells and bacterial cells
Eukaryotes

Cells that have a cell membrane, cytoplasm and genetic material (DNA) enclosed in a nucleus
Prokaryotes

Cells that are smaller than eukaryotic cells, with genetic material not enclosed in a nucleus. The DNA is a single loop and there may be one or more rings of DNA called plasmids
Cell components

Cell membrane
Cytoplasm
Genetic material (DNA)
Animal and plant cells are eukaryotic cells
Prefix

Used in science to make very small numbers more manageable
Prefixes

centi (cm) - 1 cm = 0.01 m, x 10^-2
milli (mm) - 1 mm = 0.001 m, x 10^-3
micro (μm) - 1 μm = 0.000 001 m, x 10^-6
nano (nm) - 1 nm = 0.000 000 001 m, x 10^-9
Animal cell

Contains a nucleus
Has cytoplasm
Has a cell membrane
Plant cell

Contains a nucleus
Has cytoplasm
Has a cell membrane
Has a cell wall
Bacterial cell

Genetic material not enclosed in a nucleus
Has a cell membrane
May have plasmids
Cell specialisation

The structure of different cells helps them to carry out a particular function within the organism
Cell differentiation

The process where a cell changes to become specialised
Most types of animal cells differentiate in the early stage of development
Most types of plant cells can differentiate throughout their life cycle
Light microscope

First used in 1590s, uses light rays, max magnification ~1500x, resolution 200nm
Resolution

The shortest distance between two objects that can be seen clearly
Making a wet mount slide
1. Place a thin section of the specimen onto slide
2. Place a drop of water in the middle or stain the specimen
3. Gently lower cover slip onto the specimen without trapping air bubbles
4. Soak up any excess liquid
Animal cell structure

Has a diameter of 6 mm
Actual diameter of the structure
0.15 mm
Calculating magnification

1. OBJECT (A) = 0.15 mm
2. IMAGE (I) = 6 mm
3. MAGNIFICATION (M) = I/A
The structure has been magnified 40 times
Making a wet mount slide e.g. onion cells
Bacteria multiply by binary fission
Bacteria can be grown in the lab
Testing effectiveness of antibiotics and disinfectants on bacteria
Crop plants with special features such as disease resistance can be cloned to produce large numbers of identical plants for farmers, e.g. potatoes, strawberries and dates
Chromosomes

Coiled strands of DNA molecules
Gene

A section of DNA that codes for a protein
DNA

A genetic material found in the nucleus that codes for proteins