Plasma membrane
What model describes the structure of the plasma membrane?
The fluid mosaic model
What type of transport moves substances from an area of high concentration to low concentration without energy?
Simple diffusion
Which stage of the cell cycle do most cells spend the majority of their time in?
Interphase
What is apoptosis?
Programmed cell death
What type of cell does NOT have a nucleus?
Prokaryotic cell
What are the two parts of a phospholipid molecule?
A hydrophilic head and hydrophobic tails
What process specifically refers to the movement of water across a semipermeable membrane?
Osmosis
What happens during the S phase of the cell cycle?
DNA is replicated
Why is apoptosis important for multicellular organisms?
It removes damaged, malfunctioning or unnecessary cells
What is the term used to describe how different organelles perform specific functions within a cell?
Cellular compartmentalisation
Why can small non-polar molecules move through the membrane more easily than charged particles?
Because they can pass through the hydrophobic interior of the phospholipid bilayer
What role do transport proteins play in membrane transport?
They help specific substances move across the membrane
What is the purpose of mitosis?
To produce two genetically identical daughter cells
What cellular structure is involved in the intrinsic pathway of apoptosis?
The mitochondria
Define isotonic solution.
A solution with the same solute concentration as the cell
Define selective permeability.
The ability of the membrane to allow some substances to pass while restricting others
Name the process by which a cell releases substances out of the cell in vesicles.
Exocytosis
Why are most cells found in interphase rather than mitosis?
Because interphase is much longer and involves growth, normal function, and DNA replication
What type of signal activates the extrinsic pathway of apoptosis?
External death signals binding to receptors on the cell membrane
What type of stem cell can differentiate into all cell types in the body but not extra-embryonic tissues?
Pluripotent stem cell
Explain how the structure of the plasma membrane influences the movement of substances.
The phospholipid bilayer blocks large or charged molecules, while transport proteins allow specific substances to cross
Give one example of when a cell would use endocytosis.
Define the G0 phase and give one example of a cell that remains in this phase.
G0 is a non-dividing state where cells carry out normal functions
Example: Neurons (nerve cells)
What can happen if cell growth exceeds cell death in an organism?
Tumours or cancer can develop
Identify the independent variable in an experiment testing how temperature affects enzyme activity.
Temperature