B1 Flashcards
Order of units
1 km = 1000 m
1 m = 100 cm
1 mm = 1000 micrometers
1 micrometer = 1nm
Light vs electron microscopes
Light has lower resolution and magnification
Light is b & w, electron is colour
Light is 2D, electron is 3D
Electron needs specialist training
Light is smaller
How to work out total magnification
Multiply the magnification of eyepiece lens by the magnification of the objective lens
Magnification equation
Image size = magnification x size of real object
What is resolution
The ability to distinguish between two points
What is resolving power
Affects how much detail it can show
Structures in animal cell
Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes
What does the nucleus do
Controls all the activities in the cell and contains the genes on the chromosomes that carry the instructions for making proteins needed to build new cells or organisms
What is the cytoplasm
Liquid gel in which organelles are suspended and where chemical reactions for life take place
What is the cell membrane
Controls the passage of substances such as glucose and mineral ions into the cell. Controls movement of substances such as urea or hormones out of the cell
What is mitochondria
Where aerobic respiration takes place
What are ribosomes
Where protein synthesis takes place
What is cell wall
Made of cellulose that strengthens the cell and gives it support
What are chloroplasts
Contain the substance chlorophyll which absorbs light so the plant can make food by photosynthesis
What is a permanent vacuole
Filled with cell sap which keeps the cell rigid to support the plant
What are eukaryotic cells
Have a cell membrane, cytoplasm and genetic material enclosed in a nucleus. All animals, plants, fungi and protista are eukaryotes
Example of prokaryote
Bacteria
Size of prokaryotic cell vs eukaryotic cell
Prokaryotic is much smaller
Structures in prokaryotic cell
Cytoplasm, cell membrane, cell wall (no cellulose), genetic material is in a free loop found in cytoplasm, may have plasmids, many have slime capsule, some have flagellum
Adaptations of nerve cells
- lots of dendrites to make connections to other nerve cells
- axon that carries nerve impulse from one place to another (very long)
- synapses are adapted to pass the impulses to another cell or between a nerve cell and a muscle using transmitter chemicals
- contain lots of mitochondria to provide energy needed to make transmitter chemicals