B2 - Cells Flashcards
What are basic plant cells made up of?
A cell wall, cell membrane, nucleus, vacuole, cytoplasm and chloroplasts containing chlorophyll.
What are basic animal cells made up of?
A cell membrane, nucleus, and cytoplasm.
What is the cytoplasm and what does it do?
It is jelly-like, with particles and organelles in it. it is enclosed by the cell membrane. It contains the cell organelles e.g. mitochondria, nucleus, site of chemical reactions.
What is the cell membrane and what does it do?
A partially permeable layer that forms a boundary around the cytoplasm. It prevents cell contents from escaping and controls what substances enter and leave the cell.
What is the nucleus and what does it do?
A circular or oval structure containing DNA in the form of chromosomes. It is inside the cytoplasm and controls cell division, cell development, and cell activities.
What is the cell wall and what does it do?
A tough, non-living layer made of cellulose surrounding the cell membrane. It is around the outside of plant cells. It prevents plant cells from bursting and allows water and salts to pass through (freely permeable).
What is the vacuole and what does it do?
A fluid-filled space surrounded by a membrane. It is inside the cytoplasm of plant cells. It contains salts and sugars and helps to keep plant cells firm.
What is the chloroplast and what does it do?
An organelle containing chlorophyll inside the cytoplasm of some plant cells. It traps light energy for photosynthesis.
What is the function of ciliated cells?
Movement of mucus in the trachea and bronchi
What is the function of root hair cells?
Absorption.
What is the function of palisade mesophyll cells?
Photosynthesis.
What is the function of red blood cells?
Transport of oxygen.
What is the function of sperm and egg cells?
Reproduction
What is the formula for magnification?
image size/real size
measured in mm
What is diffusion?
The net movement of particles from a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of their random movement.
What is osmosis?
The net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution), through a partially permeable membrane.
How does surface area affect diffusion?
The bigger the surface area to volume ratio of an object the faster particles will diffuse in or out of it.
How does temperature affect diffusion?
Higher temperature = more kinetic energy = faster diffusion
How does the concentration gradient affect diffusion?
Steeper concentration gradient = faster diffusion
How does distance affect diffusion?
Shorter distance = faster diffusion
What is a partially permeable membrane?
A membrane that only lets certain substances through.
What is low/high water potential?
Less water = low water potential
More water = high water potential
What is a solute?
A substance that dissolves in a solvent.
What is a solvent?
A substance that dissolves a solute.
What is isotonic?
Equal water potential.
What is hypertonic?
Lower water potential. The cell undergoes plasmolysis.
What is hypotonic?
Higher water potential.
What is a turgid cell?
A plant cell that is plump and swollen with water.
What is a flaccid cell?
A limp and wilted cell that doesn’t have as much water.
What is haemolysis?
In a solution of higher water potential, the red blood cell takes in water, swells and bursts. The ‘ghost’ of a red blood cell; just the membrane is left behind.
