Topic 3 – Classification and Biodiversity Flashcards
what is a species
a group of organisms that share similar features such as physiology, biochemistry and ecological niche.
They must be capable of breeding to produce fertile offspring
what are some issues with defining a species
Bacteria, protists and some eukaryotes do not produce sexually so the definition does not apply here
what is Biodiversity
a measure of the variety of living organisms and their genetic differences
why do we classify organisms
we need an internationally recognised way of referring to any particular living organism
a good classification system allows scientists to see how organisms are related and make these ancestral relationships clear
Biodiversity is a very important concept and we use classification to quantify it.
what is taxonomy
the science of describing, classifying and naming living organisms
the aim to make a classification system to accurately identify and represent their ancestral relationship
explain issues with taxonomy in the past and how these issues have been solved
From the time of the Greek philosopher Aristotle onward people mainly classified organisms on their physical appearance (morphology)
- people often used analogous features to classify organisms (features that look the same or have the same function but not of the same biological origin)
issues arose with spotting small differences and placing organisms in the wrong group
now we use homologous structures which show genuine common ancestry
explain the main taxonomic groups
they divide the whole living world into three domains: 1) the Archaea 2) the bacteria 3) the eukaryotes
the main groups from largest to smallest are Domain, kingdom, phylum, class, order, family, genus and species
“Dear King Philip Came Over For Good Soup”
explain the kingdom of the archaea, bacteria and eukaryotes
The archaea and bacteria only have one kingdom each within their domain
archaea: archaebacteria - ancient bacteria, found in extreme conditions and thought to be more related to early eukaryotes
Bacteria: Eubacteria - the true typical bacteria we think of from pathogens to bacteria in the gut aiding digestion
however, there are four eukaryote kingdoms:
1) Protoctista: a very diverse group of microorganisms, some are animal-like, some are plant-like and some are more fungi like
2) Fungi - all heterotrophs (eat other organisms)
3) Plantae - all autotrophs and make food through photosynthesis
4) Animalia - move their whole bodies around during at least one stage of life, include the invertebrates and vertebrates
Explain the binomial system
every organism is given 2 Latin names
The first name is the genus and the second is the species name
- use italics
- the genus name has an uppercase letter and the species doesn’t
