Classification Flashcards
What does it mean that classification systems are a hierarchy?
There are levels of organisation in the system:
bigger groups are subdivided into smaller groups
Define biodiversity:
The variety of life on earth
What are classification schemes used for?
To organise the huge range of biodiversity into groups.
How are organisms grouped?
Based on common features and characteristics (traits)
What did Linnaeus (Carl von Linne) devise?
Linnaeus devised a system of classification for living organisms known as the :
Linnaean taxonomy
This system organizes organisms into hierarchical categories called taxa, which range from broad to specific.
He also devised: Binomial naming system
What is a taxon?
Shared features/ characteristics (traits) of the organisms were used to group them s single group (the taxon)
Arrangement of taxa?
Arranged from biggest to smallest and become more specific as the size of the group gets smaller
Name the 7 taxonomic groups from biggest to smallest:
-Kingdom
-Phylum / phyla (animals) OR division (plants)
-Class
-Order
-Family
-Genus (genera)
-Species
Why was the binomial naming system (LATIN) useful for classification.
Latin was understood universally by scientists, therefore organisms could be identified and named accurately. This eliminated confusion and incorrect naming and classification
AND
Meaning of words wouldn’t change over time.
Structure of BINOMIAL NAMING SYSTEM
(Genus) (species)
Underlined **
Scientific name of HUMANS
Homo sapiens
The kingdom system of Linnaeus:
THE 5 MAIN KINGDOMS OF LIVING ORGANISMS:
- Monera
- Protista
- Fungi
- Plantae
- Animalia
The kingdom system of Linnaeus:
THE 5 MAIN KINGDOMS OF LIVING ORGANISMS:
- Monera
- Protista
- Fungi
- Plantae
- Animalia
How are organisms grouped into the 5 kingdoms?
Based on Diagnostic features
- Body structure
- Cell structure
- Cell wall composition
- Mode of nutrition
- Type of reproduction
monera: body structure
Unicellular / colonies
Protista: body structure
Unicellular / Multicellular
Fungi: body structure
Multicellular
(Few are unicellular - eg. Yeast)
Plantae: body structure
Multicellular
Animalia: body structure
Multicellular
(Some unicellular -amoeba)
Monera: cell structure
Prokaryotic
Protista: cell structure
Eukaryotic (true nucleus)
Fungi: cell structure
Eukaryotic
Plantae: cell structure
Eukaryotic
Animalia: cell structure
Eukaryotic
Monera: cell wall composition
Cellulose
(Some : chitin)
Protista: cell wall composition
Cellulose
(Some none)
(Some chitin)
Fungi: cell wall composition
Chitin
(Some: cellulose)
Plantae: cell wall composition
Cellulose
Animalia: cell wall composition
None
Monera: mode of nutrition
Heterotroph
(Some autotroph : Cyanobacteria)
Protista: mode of nutrition
Heterotrophic;
(Some autotroph)
Fungi: mode of nutrition
Heterotroph
Plantae: mode of nutrition
Autotrophic
(Some: heterotrophic)
Animalia: mode of nutrition
Heterotrophic
Monera: type of reproduction
Asexual
Protista: type of reproduction
- Asexual: in favourable (good) conditions
*Sexual: in unfavourable conditions only. (Survival)
Fungi: type of reproduction
- Asexual: favourable conditions
- Sexual: unfavourable conditions only
Plantae: type of reproduction
- Asexual: favourable conditions
*Sexual: unfavourable conditions only
**EXCEPT: Angiosperms (flowering plants) = Sexual reproduction
Animalia : type of reproduction
Sexual
OR Asexual (unicellular organisms)
Why are viruses not classified into a group
Viruses are non-living: inactive until in a cell
Which kingdoms are microorganisms.
CAN’T BE SEEN WITH NAKED EYE
- Monera
- Protista
- Fungi
Which kingdoms are macro-organisms ?
CAN BE SEEN WITH NAKED EYE
- Fungi
- Plantae
- Animalia
Define: Organism
An organism must possess the 7 life processes to be classified as living
(Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition
Define: Microorganisms
These organisms are not visible to the naked eye.
Magnification allows them to be seen (microscope, hand lens)
*Viruses don’t belong to a kingdom but are also microorganisms
Define: Macroorganisms
Organisms which are larger than microorganisms and are visible to the naked eye.
Define: Species
A species is a group of organisms with:
1. Shared characteristics
2. Living in a defined area
3. Close enough to interbreed
4. Produce a fertile offspring
Define: viruses
Viruses are not currently classed as a living organism as they do not present the 7 life processes.
*they only REPRODUCE (must be inside cell to do so)
* ACELLULAR (not true cell): parasitic particles organised at basic level
*Only active once inside host cell , using host cell’s structures to reproduce. When they are not inside the cell, they are inert (inactive)
Eg. HIV, influenza , colds
Acellular =
Not true cell
Inert=
Inactive
Parasitic=
Harmful
(Lives on other organisms)
Define: Classification/ Biological key
A classification key is a series of questions that determine an organism’s physical characteristics
and when you answer one question, it either branches off to another question or identifies the organism.
What are keys used for?
- Identify an unknown organism
- Work out how to categorise groups of similar organisms
Type of key:
Dichotomous Key :(flow chart / list)
A tool that uses a series of yes or no questions, statements, or descriptions that are ordered or grouped in pairs in order to identify a specimen within a defined group of specimens.
Explain Linnaeus’s contribution to modern biology
Came up with taxonomic groups and 5 kingdom classification used to SORT and GROUP organisms
Why is it important to record indigenous knowledge (medicinal use)
Preserves for future generations: cultural heritage
More accurate than to pass info down orally
Why is it important to record common names
Common names reflects a plant’s apparence and use
Most people in community know common name, making it easier for scientists to find
- more accessible = increased awareness = increased conservation
Why do scientists collect many samples before classifying?
To observe and study: physical characteristics
*then group based on similarities and differences
Scientist’s next step after collecting samples:
- Make observations : similarities/ differences
- Drawings with annotations: to record specific characteristics
What type of scientist studies the classification of organisms?
Taxonomist
Scientific skill: ready a dichotomous key
Critical physical observation
