Cells Flashcards
Magnification Equation
Magnification= image size / size of real object
Difference between Electron and Light Microscope
An electron microscope has much higher magnification and resolving
power which can be used to
study cells in much finer detail. Enables us to see and understand many more sub-cellular structures.
Function of Nucleus
- Eukaryotic only *
Controls all the activities of the cell.
Contains the genetic material.
Function of Cytoplasm
- All Cells *
Liquid gel where organisms are suspended and site where most chemical reactions take place.
Function of Ribosomes
- Eukaryotic only *
Protein synthesis takes place, making all proteins for the cell.
Function of Mitochondria
- All Cells *
Aerobic respiration - releasing energy for the cell.
Function of Cell Wall
- Plant Cells + Prokaryotes *
Supports and protects internal structures and organelles
Function of Cell Membrane
- All cells *
Controls the passage of substances in and out of the cell.
Function of Permanent Vacuole
- Plants only *
Space filled with cell sap.
Keeps cell rigid to support plant.
Function of Chloroplasts
- Plants only (except RHC) *
Make food by the process of photosynthesis
Function of Chlorophyll
- Plants only (except RHC) *
Absorbs light so plant can make food by photosynthesis
Where is chlorophyll found?
Chloroplasts
What gives plants their green pigment?
Chlorophyll
What is the cell wall made up of ?
Cellulose to strengthen the cell
Definition - Eukaryotic
Genetic material is enclosed in a nucleus
Definition - Prokaryotic
Genetic material is not enclosed in a nucleus.
Difference between Prokaryotes and Eukaryotes
Prokaryotes are….
- smaller
- don’t have a nucleus
- may have plasmids
Definition - Plasmids
Small rings of DNA that code for specific features such as antibiotic resistances
What type of cell is a bacteria?
Prokaryotic
Example of animal specialised cells
Nerve Cell, Sperm Cell, Muscle Cell
Example of plant specialised cells
Xylem Cell, Phloem Cell, Root Hair Cell
Adaptations of a nerve cell (3)
- Lots of dendrites that make connections to other cells
- Axons that carry the impulse from one place to another
- Synapses aww adapted to pass the impulse to another cell or between a nerve cell and a muscle cell
Adaptations of Muscle Cells (3)
- Contain proteins that slide over each other and make the fibres contract
- Contain many mitochondria to transfer energy needed for chemical reactions to take place
- Store glycogen, which can be broken down and used in cellular respiration by the mitochondria to provide energy needed for the fibres to contract.
Adaptations of Sperm Cells (4)
- Long tail helps it to move
- Middle section is full of mitochondria, which provide energy for the tail
- Large nucleus contains genetic information to be passed on
- Acrosome stores digestive enzymes to break down the outer layers of the egg
Adaptations of a Root Hair Cell - RHC (3)
- Increased surface area for water to move into the cell
- Permanent vacuole that speeds up movement of water by osmosis from the soil across the root hair cell
- Many mitochondria to transfer energy needed for active transport
Adaptations of Xylem Cell (2)
- Alive at first but die and form long hollow tubes to allow water and mineral ions to move easily through them
- Spirals is lignin make them very strong and help them to withstand pressure of water. Also help support phloem.
Adaptations of Phloem Cell (2)
- Cell walls between the cells break down to form special sieve plates. Allow water carrying dissolved food to move freely
- Supported by companion cells which transfer energy and support them.
