Cell Biology Flashcards
What are examples of specialised cells?
Sperm, nerve, muscle, root hair, phloem and xylem cell.
What do bacterial cells contain?
A plasmid
How many pairs of chromosomes does a human have?
23
Where does gas exchange take place?
In the aveoli
What is diffusion?
Diffusion is the spreading out of particles from an area of higher concentration to an area of lower concentration.
What are cell membranes?
Cell membranes are semi-permeable, only small molecules can get through.
What is osmosis?
Osmosis is the movement of water molecules across a partially permeable membrane from a region of higher concentration to a region of lower concentration.
What is active transport?
Active transport is the movement of substances against the concentration
gradient. This process requires energy from respiration.
What is the independent variable in osmosis and potato practical?
The concentration.
What is the control variable in osmosis and potato practical?
Volume of solution, temperature time, surface area of the potato.
What is the dependent variable in osmosis and potato practical?
Change in mass
What is the conclusion of the osmosis and potato practical?
The potato in the sugar solution will lose water and so will have less mass at the end; the potato in the pure water solution will gain water.
What is differentiation?
When a cell changes to become a specialised cell.
What is a sperm cells’ function?
To get from the male DNA to the female DNA.
What is the nerve cells’ function?
To send electrical impulses around the body.
What is the muscle cells’ function?
To contract quickly.
What is the root hair cells’ function?
To absorb water from the soil.
What is the phloem’s function?
Transports substances around the plant.
What is xylem’s function?
Transports water through the plant.
How do you convert micrometers to millimeters?
Divide by 1000
What does the microscopy practical involve?
Includes preparing a slide, using a light microscope,
drawing any observations – use a pencil and label important observations.
What are the 3 things a plant cell have that an animal cell does not?
A chloroplast, vacuole and cell wall.
What does a bacterial cell contain?
A plasmid.
Describe a bacterial cell.
Bacterial cells do not have a true nucleus, they just have a single strand of DNA that floats in the cytoplasm.
