Chapter 1+2 - Cells And Organisation Flashcards
How do you calculate total magnification
Eyepiece lens x objective lens
Define the term resolution
Resolution is the ability to distinguish between two separate points in an image
What is the role of the nucleus
Contains DNA in the form of chromosomes. Controls the cell
What is the role of the cytoplasm in a cell
This is where chemical reactions take place
What is the function of the cell membrane
Controls what enters and leaves the cells
What is the function of the mitochondria in cells
This is the site of respiration.
Glucose + oxygen –> carbon dioxide + water vapour + ATP energy
Definition of magnification
Magnification is how much bigger an image is compared to its actual size. Can be calculated by using IAM triangle
Function of the cellulose cell wall
This is the 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
Traps sunlight energy which is needed for photosynthesis
What is diffusion
The movement of particles from a high concentration to a low concentration. No energy is needed
How does the concentration effect the rate of diffusion
The higher the difference in concentration the faster the rate is
How does the distance effect the diffusion rate
If there is a less distance for the particles to travel
What is osmosis
The movement of water molecules from an area of high concentration to an area of low concentration across a partially permeable membrane
What happens when an animal cell goes into a dilute solution
There is low concentration of water inside the cell and there is a high concentration of water outside therefore water goes in the cell by osmosis across a partially permeable membrane causing the cell to expand and burst this is known as lysis
What happens when an animal cell goes into concentrated solution
There is low concentration of water outside the cell and there is a high concentration of water inside therefore water leaves the cell by osmosis across a partially permeable membrane and as a result the cell has shrunk and shrivelled. This is known as crenated (lack of water)
IAM triangle
Image, actual size, magnification
Permanent vacuole
A space in the cytoplasm filled with cell sap
Eukaryotic cells
Plant and animal cells which has DNA to form chromosomes
Prokaryotic cells
Bacteria is a prokaryotic so they are single-celled living organisms. It does not have a nucleus
What happens when a plant cell goes into a dilute solution
There is a high concentration outside the cell and a low concentration inside the cell. Water would move inside the cell by osmosis through a partially permeable membrane causing the cell to expand but not burst. This is process is called turgid
What happens when a plant cell goes into concentrated solution
There is a high concentration inside the cell and a low concentration outside so the water leaves the cell by osmosis through a partially permeable membrane causing it to come off the cell wall. This is known as plasmolysis
Plasmids
Extra small rings of DNA found in prokaryotic cells
Embryonic stem cells
Can develop into almost every cell
