Chapter 14- Classification Flashcards
Who introduced the idea of classification
English scientist John Ray surveyed many plant species and gave them short descriptive Latin names.
Carl Linnaeus standardised the binomial system for naming species. He gave every species two names (like a first and surname). The first name reflected the way in which he classified the species and the second often gave some information about it. This is often done to avoid confusion between other species. Ex: the Apodemus sylvaticus which translates to ‘not house, wood’ because this species is often confused between house mouses ‘Mus musculus’.
What are subspecies
When species are subdivided into subspecies. In this case, a third name is given.
What does the first name show
The genus (or generic name). This indicates a rank higher than species in the classification system. Species that show too many similarities and are closely related are classified together in the same genus.
What does the second name show
This is the specific epithet. However, the name of the species is both words (the genus and the epithet). The epithet refers to the one species within the genus.
How do you abbreviate the name of a species
The first letter of the genus followed by the epithet.
Why is the Genus name not unique
A genus name cannot be used for more than one animal genus just like how a specific genus name cannot be used for more than plant genus.
However, the same genus name can be used for one animal genus and one plant genus.
Ex: Pieris brassicae a cabbage white butterfly
Plant known as Japanese andromeda is Pieris japonica.
Are epithets unique
No, some specific epithets are used for many species.
Which international organisations are responsible for devising codes that regulate the naming of organisms
International Code of Zoological Nomenclature for animals
International Code of Nomenclature for Algae, Fungi and Plants
International Code for Nomenclature of Bacteria
Who are taxonomists
They are biologists who specialise in describing, naming and classifying living and extinct organisms.
Definition of Taxonomy
This is the study of classification and the way in which features are used to distinguish between different species and to group them together.
Definition of classification
This is the organisation of living and extinct organisms into groups that are arranged in a hierarchy.
Some classifications are natural, in that they attempt to show relationships between species based on a study of many features.
Others are artificial and are done for a specific purpose.
What is a hierarchical classification system
This is where large groups were continually subdivided down to the level of the species.
The hierarchical classification- taxonomic ranks (taxons)
Species Genus Family Order Class Phylum Kingdom
What are the five kingdoms
Prokaryota Protoctista Fungi Plantae Animalia
Prokaryota kingdom
Includes the bacteria and blue-green bacteria
Most prokaryotic cells exist as single cells, filaments of cells or groupings of similar cells known as colonies.
Prokaryotic cells are about 1 micrometre in diameter.
They make up 90% of the ocean’s biomass
Live in a variety of habitats, including extreme conditions of heat, pH and salinity that kills eukaryotes.
Autotrophic prokaryotes
Blue-green bacteria and some bacteria are photosynthetic and fix carbon dioxide and produce oxygen in the same way that green plants do
Autotrophic means when light is used to produce food
Heterotrophic prokaryotic cells
Decomposers on organic material, both living and dead.
A heterotroph is an organism that cannot manufacture its own food by carbon fixation and therefore derives its intake of nutrition from other sources of organic carbon, mainly plant or animal matter.
These are generally the secondary or tertiary consumers.
Examples of heterotrophics
Some parasites:
Neisseria meningitidis
Mycobacterium tuberculosis
Cause diseases in human
Why are prokaryotic cells important
They are important in recycling elements such as nitrogen, phosphorus and sulphur. Some live in anaerobic conditions and produce methane (CH4) as a waste.
Some prokaryotic cells can fix nitrogen gas (dinitrogen- N2) to form ammonia from which they can synthesise many nitrogenous compounds. Others can make use of other inorganic substances in place of oxygen in respiration.
How does cell division occur in prokaryotic cells
Prokaryotes do not have linear chromosomes like eukaryotes and they do not divide by mitosis.
Their DNA replicates in the same way as in eukaryotes but there is no nuclear envelope to break down and there is no separation of chromosomes so there is no anaphase
Cell division occurs by binary fission, which is a form os asexual reproduction.
The transfer of genetic material from one individual to another happens when bacteria join together and exchange DNA.
Plasmids are also exchanged between bacteria, even between bacteria from different species.
Due to this, bacteria can gain new genes such as those for antibiotic resistance.
How were mitochondria and chloroplasts formed
From bacteria that invaded or were taken in by eukaryotic cells than a billion years ago.
Hence the similarities between bacteria and these organelles
Kingdom Protoctista
Protozoans (‘simple animals’) such as algae (ex: seaweeds)
Any eukaryote that is not a fungus, plant or animal is classified as a protoctist.
Many such as Paramecium are single celled; some are filamentous and some, such as Pediastrum duplex, are groups of similar protoctists known as colonies.
Seaweed?
Most complex multicellular protoctist
Their bodies are not differentiated into organs such as roots, leaves and stems but different areas of the body are specialised for attachment, photosynthesis and sexual reproduction.
Many organisms in this kingdom are more closely related to organisms from other kingdoms than they are to each other. Some might argue that algae (ex: seaweed) is more closely related to the plant kingdom
Where are protoctists found
In many different natural and artificial environments
Algae are important photosynthetic organisms in aquatic ecosystems. Ciliates are important in sewage-treatment works, where they feed on bacteria, keeping their numbers in check. Some, such as Plasmodium, which causes malaria, are important human and animal pathogens.
Kingdom Fungi- what are they and why can they be useful?
All fungi are heterotrophic, obtaining energy and carbon from dead and decaying matter or by feeding as parasites.
Fungi are just as important as decomposers aiding the recycling of carbon (as CO2) and mineral elements such as nitrogen. None of the fungi can photosynthesise.
