Introduction to cells - Coggle Diagram
Introduction to cells
Types of eukaryotic cells
Eukaryotic cells have similar structures across different types of organisms. But there are some key differences that are outlined here.
Animal cell structure
Plant cell structure
Algal cells and plant cells have an identical set of organelles.
Fungal cells are similar to plant cells, apart from:
There are no chloroplast in fungal cells.
The cell walls of fungal are made from chitin instead of cellulose
Eukaryotic vs Prokaryotic cells
All life on Earth exists as cells. A cell is the smallest unit if a living thing. All cells can be grouped into either eukaryotic or prokaryotic cells. These different categories have similarities and differences.
Both eukaryotic and prokaryotic cells contain organelles.
The cell-surface membrane in eukaryotic and prokaryotic cells is made of a phospholipid bilayer.
This bilayer is responsible for controlling the passage of substances across exchange surfaces.
Prokaryotic cells make up single-celled prokaryotic organisms (e.g. bacteria). In contrast, eukaryotic cells make up complex eukaryotic organisms (e.g. animals, plants, fungi and algae).
Eukaryotic cells are larger and more complex than prokaryotic cells.
Cells arise from other cells by binary fission in prokaryotic cells and by mitosis or meiosis in eukaryotic cells.
Eukaryotic = 10-100um
Prokaryotic = 0.1-5.0um
Specialisation and organisation of cells
In complex multicellular organisms, cells gain specific features. This is called specialisation. Specialised cells are then organised into groups to perform a function.
A cells specialises because the shape and contents of a cell help it to carry out its function. Examples include:
Muscle cells are very active so contain lots of mitochondria in order to produce ATP.
Red blood cells have a biconcave shape and no nucleus to maximise space to carry oxygen.
Palisade cells have a long, upright shape and contain chlorophyll to absorb light for photosynthesis.
Specialised cells are organised into tissues, tissues into organs and organs into organ systems.
Tissues - muscle tissue or xylem tissue
Organs - the animal heart or plant leaf
Organ systems - the female reproductive system, which includes uterus, ovaries, mammary glands and breasts)