B1: The world of the Microscope Flashcards
What is the function of a nucleus in a eukaryotic cell?
Controls cell activities and contains genetic material
What is the size of prokaryotic cells, compared to eukaryotic cells?
They are much smaller
Where is the genetic material located in prokaryotic cells?
No nucleus, single loop of DNA alongside small loops called plasmids
How is a sperm cell adapted to its function?
Half genetic information
Tail to help them swim
Streamlined head to help swim
Many mitochondria for energy to swim
How is a nerve cell adapted to its function?
Long axon, carries the electrical impulse between body parts
Myelin sheath for isolation and increases efficiency
Synapses at the end of the cell
Dendrites, increase surface area to connect with other nerve cells
How is a muscle cell adapted for its function?
Long protein fibres that can change their length
Many mitochondria for energy
What is diffusion?
The spreading out of particles, resulting in a net movement from an area of high concentration to an area of low concentration.
How can diffusion efficiency be increased?
Increase conc. gradient
Increase temp.
Increase SA of cell membrane
What is osmosis?
The movement of water (specifically) from a dilute solution to a concentrated solution through a partially permeable membrane
What happens when you place an animal cell in water?
Water will move into the cell and cause it to swell and possibly burst
(cytoplasm is concentrated, thus more water comes in the cell than leaves it)
What do micro and nano refer to?
Micro = 1/1,000,000 of a metre (110^-6)
Nano = 1/1,000,000,000 of a metre (110^-9)
What is the size of a typical human cell?
10-20 micrometers
What structures are measured in nanometres?
Proteins
Haemoglobin
etc.
What is an order of magnitude?
Every order of magnitude is 10x greater than the one before. e.g. 10x = 1 order, 100x = 2 orders, 1000x = 3 orders.
