bioligy year 9 Flashcards
What is osmosis?
The movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
True or False: Osmosis requires energy.
False
Fill in the blank: Osmosis is a type of __________ transport.
passive
What is diffusion?
The movement of particles from an area of higher concentration to an area of lower concentration.
Which of the following substances can diffuse through a cell membrane? a) Water b) Oxygen c) Glucose d) Both a and b
d) Both a and b
Define selectively permeable membrane.
A membrane that allows certain molecules to pass through while blocking others.
True or False: Osmosis only involves the movement of solutes.
False
What happens to a cell placed in a hypertonic solution?
The cell will lose water and shrink.
What is a hypotonic solution?
A solution with a lower concentration of solutes compared to another solution.
Fill in the blank: In a __________ solution, cells swell as water enters.
hypotonic
What is isotonic solution?
A solution where the concentration of solutes is equal inside and outside the cell.
True or False: In diffusion, particles move against their concentration gradient.
False
What role do proteins play in osmosis?
They can act as channels to facilitate the movement of water across the membrane.
Multiple Choice: Which process is primarily responsible for the uptake of water by plant roots? a) Diffusion b) Osmosis c) Active transport d) Endocytosis
b) Osmosis
What is the main difference between osmosis and diffusion?
Osmosis specifically refers to the movement of water, while diffusion refers to the movement of any particles.
Fill in the blank: Water moves from areas of __________ concentration to areas of __________ concentration during osmosis.
low, high
What can be the effect of osmosis on red blood cells in a saline solution?
They may crenate (shrink) in hypertonic solutions or lyse (burst) in hypotonic solutions.
True or False: Diffusion can occur in gases, liquids, and solids.
True
What is facilitated diffusion?
A process where specific molecules are transported across a membrane via protein channels.
Multiple Choice: Which of the following is NOT a factor affecting the rate of diffusion? a) Temperature b) Concentration gradient c) Molecular size d) Color of the substance
d) Color of the substance
What happens to the rate of osmosis if the temperature increases?
The rate of osmosis generally increases with temperature.
Fill in the blank: The __________ is a measure of the concentration of solute in a solution.
osmolarity
What is osmotic pressure?
The pressure required to stop the flow of water across a semipermeable membrane due to osmosis.
