Classification Flashcards
Why is classification important?
- To organise the enormous amount of species so we can see patterns and relationships between them.
- To collect data to compare and evaluate.
- To easily identify invasive species and reduces the risk of misidentification of endangered species.
- Creates a common language to use when communicating internationally to identify species and compare findings.
What is classification based on?
Characteristics of organisms that include morphological features, reproductive methods and molecular sequences.
How is classification based on morphological characteristics?
Classification is based on the idea that members of the same group share characteristics. Linnaeus originally used physical (morphological) characteristics to classify organisms.
How are organisms classified based on methods of reproduction?
Organisms reproduce in different ways, organisms that reproduce in similar ways can be classified based on this reproduction method. E.g. reptiles and birds lay eggs. Fungi, ferns and mosses produce spores. etc.
How is molecular sequences used to classify organisms?
New technology has allowed for the analysis of chemical sequences in molecules such as DNA and proteins to be used to classify organisms.
Can be used when morphological evidence is unclear.
What does classification of organisms show?
Reflects their evolutionary relationships. Shown on a phylogenetic tree.
All organisms originated from a single common ancestor that lived at some point in the past. Over time populations change as organisms adapt to their environment. Slow incremental changes lead to the evolution of a new species. Multiple species can arise from the same common ancestor but the more recently that the common ancestor of the two species lived the more closely related they are.
What system is used for scientifically naming organisms?
Binomial system/binomial nomenclature.
What is the binomial naming system?
Scientific name have 2 parts, the first part is the genus that organisms is in, the second part is the species. The genus is capitalised the species is not. The whole name is italicised when printed and underlined when handwritten.
Why is the binomial naming system used?
It is an international naming system, meaning it allows people from other areas to understand.
What are the levels of taxonomy in order?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
What are domains?
Domains are organised based on cellular characteristics eg. organisms from Domain Eukarya (Eukaryotes) contain DNA within a nucleus and membrane bound organelles, Prokaryotes do not.
What are the 2 types of kingdoms in the prokaryotes?
- Archaea
- Bacteria
Compare and contrast archaea and bacteria.
- Archaea: Live in extreme environments, eg. high temp or salt, cell wall composed of Pseudopeptidoglycan
- Both: Prokaryote, microscopic, single celled, asexual reproduction (fission, budding), used to be considered one group called Monera.
- Bacteria: Can live in all environments,
cell wall composed of Peptidoglycan / Lipopolysaccharide, some types can reproduce through spores
What are the 4 types of Kingdom int eukaryotes?
- Plantae: Able to obtain energy from the sun using chloroplasts (autotrophs), have cell walls that contain cellulose
- Animalia: All of the animals, heterotrophs, largest number of named species.
- Protista: mostly single celled, live in aquatic environments.
- Fungi: Cell walls made of chitin Yeast, mushrooms and moulds.
What are the 9 major animal phyla?
- Chordata
- Echinodermata
- Porifera
- Nematoda
- Annelida
- Mollusca
- Arthropoda
- Platyhelminthes
- Cnidaria
