Flashcards in Chapter 1 Deck (33):
How do you find total magnification?
Eye piece lens * objective lens
What is magnification?
Magnification is how large the image is compared to it's actual size
What is the definition resolution?
Resolution is the ability to distinguish between two separate points in an image.
What does an iam triangle do?
An iam triangle can find the image size, actual size or magnification using equations.
What is the role of the nucleus
Contains DNA in the form of chromosomes. Contains the genetic code.
What is the role cytoplasm in a cell
This is where chemcial reactions take place
What is the function of the cell membrane
Controls what enters and leaves the cells.
What is function of the mitochondria is cells
This is the site of respiration.
Glucose + Oxyen --> Carbon dioxide + water vapour + ATP energy
Function of the cellulose cell wall
This is outer layer of plant cells. It is made of cellulose. It gives the plant strength and support.
Why are ribosomes needed in a cell?
Ribosomes are the site (location) where proteins are made.
What is the function of chloroplasts in plant cells?
Chloroplasts contain a green chemcial called chlorophyll. It traps sunlight energy which is needed for photosynthesis.
What is a vacuole and what does it do
Filled with cell sap to keep the cell turgid
What is a eukaryotic cell
A eukaryotic cell is a cell with 46 chromosomes in the nucleus.
What is prokaryotic cell?
A prokaryote is a unicellular organism that lacks a membrane-bound nucleus (karyon), mitochondria, or any other membrane-bound organelle.
What is a plasmid?
a genetic structure in a cell that can replicate independently of the chromosomes,
typically a small circular DNA strand in the cytoplasm of a bacterium or protozoan.
Plasmids are much used in the laboratory manipulation of genes.
What is the order of magnitude?
the forces between atoms on a polymer chain are about two orders of magnitude stronger than those between chains
Nerve cell adaptions?
The sheath acts as an insulator - rather like the plastic coating of an electrical wire.
Neurones are adapted to their function by being long, so that they communicate with distant parts of the body.
They also have branched endings called dendrites.
Muscle cell adaptions?
They are cells found in muscles in animals, they contract and relax together to move the organisms.
Their function is to contract to support and move the body.
They are adapted by two ways, First, Is that they are made of contractile filament to help in contraction.
Sperm cell adaptions?
Long 'finger-like' process with very thin wall, which gives a large surface area.
The head contains genetic information and an enzyme to help penetrate the egg cell membrane.
The middle section is packed with mitochondria for energy.
The tail moves the sperm to the egg.
Root hair cell adaptions?
Root hair cells are adapted for this by having a large surface area to speed up osmosis.
What are xylem cells
xylem cells are the long tracheary elements that transport water. Tracheids and vessel elements are distinguished by their shape.
What are phloem cells?
Phloem, also called bast, tissues in plants that conduct foods made in the leaves to all other parts of the plant.
What is diffusion?
Diffusion is the movement of cells from a high concentration to low concentration.
What is the rate of diffusion?
The rate of diffusion is increased when: The distance is decreased. The surface area is increased. The concentration difference (concentration gradient) is increased.
What does dilute mean?
Where there is more water and less solution.
What does concentrated mean?
Where there is less water and more solute.
What is osmosis?
Osmosis is the movement of water particles from high to low concentration.
What is a crenated cell
A process resulting from osmosis in which red blood cells, in a hypertonic solution, undergo shrinkage and acquire a notched or scalloped surface.
What is a lysis cell
Lysis refers to the breaking down of the cell, often by viral, enzymic, or osmotic mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a "lysate".
What is plasmoysis
contraction of the protoplast of a plant cell as a result of loss of water from the cell.
What is a turgid cell?
When the plant cell is placed in a hypotonic solution , it takes up water by osmosis and starts to swell, but the cell wall prevents it from bursting. The plant cell is said to have become "turgid" i.e. swollen and hard.
What is turgor pressure
Turgor pressure is the pressure of water pushing the plasma membrane against the cell wall of a plant cell.