How to classify organism?
There are millions of different plants and animals in the world. To make it easier to identify them, we place them into different groups. These groups contain organisms whose characteristics are similar. The process of classifying organism is called taxonomy. Classification itself means identifying and grouping organisms.
Living organisms are placed into groups, called kingdoms.
In I/GCSE Biology, there are five kingdoms:
- Unicellular – have a cell wall, cell membrane, cytoplasm and plasmids
- Lacks nucleus but contains DNA
- Some can photosynthesis but most feed off other living or dead organisms
- Examples include Lactobacillus bulgaricus
Viruses are parasitic, smaller than bacteria, have no cellular structure but have a protein coat and one type of nucleic acid, either DNA or RNA. They can only reproduce inside living cells and infect every type of living organism. Examples include the influenza virus, and HIV. Fungi, bacteria, protoctists or viruses can be pathogens – agents that cause disease.
*Note: Viruses are NOT living things. They do not feed, respire, excrete, move, grow or respond to their surroundings. They only reproduce – but they do it parasitically by entering a host cell and taking over the host’s genetic machinery to make more virus cells.
How to define ‘Living’ ?
Genus V.S. Species
A genus is the second last classification group. Kingdoms such as animals are divided into smaller groups such as mammals. That can then be divided into even smaller groups such as… dolphins! And then even smaller, such as pink-nose dolphin! Get the idea? Unfortunately we’re talking about Latin names here.
Key point here: No different species can reproduce with each other.
An example would be Homosapien. ‘Homo’ is the genus, because there are lots of other ‘Homos’ out there such as Homo neanderthelansis. ‘Sapien’ is the species name.
Other Groups Lower Down Kingdoms 👇👇
Anyways these are the groups from the biggest down to the smallest – or from the very first level of classification down to the last.😁😁😁
That's the end of the topic!
Drafted by Joey (Biology)