Topic 1 Cell Biology Flashcards
What type of cells do animals, plants and fungi have?
Eukaryotic
Where do most of the chemical reactions in a cell happen?
In the cytoplasm
What is the function of the cell membrane?
It controls the movement of substances in and out the cell
What is the function of the cell wall?
It strengthens the cell and supports the plant
What is the function of the permanent vacuole?
It is filled with cell sap to help keep the cell turgid
Where is genetic material found in a prokaryotic cell?
DNA is a single loopin cytoplasm and also in small rings called plasmids.
Are prokaryotic cells bigger or smaller than eukaryotic cells?
Much smaller
What is the size of a micrometre?
1/1,000,000th of a metre(1 millionth)
What is the symbol for a micrometre?
Looks like an upside down h and an m
What is a micrometre in standard form?
1x10(-6)m
What is the size of a nanometre?
1/1,000,000,000th of a metre (1 billionth)
What is the symbol for a nanometre?
nm
What is a nanometre in standard form?
1x10(-9)m
What is the orderof magnitude?
number used for size comparisons, for each order of magnitude, number is 10 times previous
What is one order of magnitude?
10x greater
What is two orders of magnitude?
100x greater
What is three orders of magnitude?
1000x greater
Are mitochondria larger or smaller than ribosomes?
Larger
What is the cell wall made from?
Cellulose
What is the vacuole filled with?
Cell sap
What is cell differentiation?
When cells become specialised
How are sperm cells adapted for fertilisation?
- head of the sperm contains genetic information
- tail and streamlined shape to swim to the egg
- mid piece packed with mitochondria- releases energy for swimming and fertilisation
- acrosome contains enzymes allow sperm to penetrate/digest way through eggs outer layer
Where is the genetic information contained in a sperm cell?
In the nucleus in the head
Where is the mitochondria contained in a sperm cell?
The mid piece/middle
Where are the enzymes contained in a sperm cell?
In the acrosome (top of the head)
What is the function of the mitochondria in a sperm cell?
Release energy needed to swim and fertilise the egg
What is the function of the enzymes in a sperm cell?
Allow sperm to penetrate/digest their way through outer layer of the egg
What is the function of the nerve cell?
To send electrical impulses around the body
What is the function of the axon in a nerve cell?
Carries electrical impulses from one part of the body to another
What is the axon in a nerve cell?
Long thin part in the middle
What is the myelin in a nerve cell?
A fatty sheath that covers the axon
What is the function of myelin?
Insulates nerve cell and increases speed of transmission of nerve impulses
What is the function of synapses in a nerve cell?
Junctions (at the end of the axon) that allow impulse to pass from one nerve cell to another
What are dendrites in a nerve cell?
Projections from the cell body
What is the function of dendrites?
Increase the surface area available to receive information from other nerve cells
What is another name for a nerve cell?
Neuron
What are the two ways muscle cells are adapted to contract?
- contain protein fibres
- contain mitochondria
What is the function of mitochondria in a muscle cell?
Provide energy for muscle contraction
What is the function of protein fibres in a muscle cell?
Allow muscle cell to contract (get shorter)
What plant cell organelle does a root hair cell not contain?
Chloroplasts - root hair cells are underground
What is the function of the root hair cell?
To absorb water and mineral ions
How is the root hair cell adapted to increase the rate of absorption?
large surface area
Where are xylem found?
Plant Stem
What is the function of the xylem?
Transport water and mineral ions from roots to leaves