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.