Characteristics, Classification and Features of Organisms Flashcards
What are eukaryotic organisms?
Eukaryotic organisms can be multicellular or unicellular and contain a nucleus with a distinct membrane.
Examples include plants, animals, fungi, and protoctists.
How do prokaryotic organisms differ from eukaryotic organisms?
Prokaryotic organisms are always unicellular, do not contain a nucleus, and have their genetic material unbound in the cytoplasm as nucleoid DNA. They lack membrane-bound organelles.
An example of prokaryotic organisms is bacteria.
What are the characteristics of plants?
Plants are multicellular organisms with cells that contain chloroplasts for photosynthesis, a cellulose cell wall, and they store carbohydrates as starch or sucrose.
Examples include maize, peas, and beans.
What are the characteristics of animals?
Animals are multicellular organisms that do not have chloroplasts, cannot perform photosynthesis, lack cell walls, usually have nervous systems, can move, and store carbohydrates as glycogen.
Examples include humans, dogs, and mosquitoes.
What are protoctists?
Protoctists are a diverse group of eukaryotic organisms that are not classified into the other three eukaryotic groups. They can be single-celled or consist of similar cells.
An example of a protoctist is amoeba.
What type of organisms are bacteria?
Most are unicellular.
What structures do bacterial cells have?
Their cells have cell walls (not made of cellulose) and a cytoplasm, but no nucleus or mitochondria. Some species have another layer around this wall called a capsule.
What are plasmids?
Small circular rings of DNA that the majority of bacteria have.
How do bacterial cells divide?
They divide by binary fission or budding.
How do bacteria compare in size to eukaryotes?
Bacteria are smaller than eukaryotes.
What enables most bacteria to move?
Most have a flagellum which enables them to move.
Give an example of bacteria.
E.g. E. coli, Bacilli, Chlorella
What are the main components of an animal cell?
Cell membrane, nucleus, mitochondrion.
What additional structures do plant cells have compared to animal cells?
Plant cells contain a large permanent vacuole, cellulose cell wall, and chloroplasts.
What is the main difference between light and electron microscopes?
Electron microscopes have a higher resolution and magnification than light microscopes, but specimens must be dead to be seen under them and they are more expensive.
How is magnification calculated?
Magnification = Image size / actual size.
What are the levels of organisation in biology?
Organelles → Cell → Tissue → Organ → Organ system
What is an organelle?
Small structures within the cell which carry out a particular function.
What is a cell?
The basic structure and functional unit of a living organism, that can operate by itself or as part of a tissue.
What is a tissue?
Groups of cells with similar structure, working together to perform a similar function.
What is an organ?
Structure made up of a group of tissues, working together to perform specific functions.
What is an organ system?
Group of organs with related functions, working together to perform body functions.
What is the function of the nucleus?
Contains genetic material in chromosomes which controls how cells grow and work. Controls cell division.
What is the function of the cytoplasm?
Supports cell structures, site of many chemical reactions in the cell and contains water and solutes.
