Classification Flashcards
What is classification?
The process of living organisms being sorted into groups
What are taxonomic groups?
A classification system based on hierarchy
What are the 7 groups in the major taxonomic groups?
Kingdom Phylum Class Order Family Genus Species
What are the three reasons that scientists classify organisms?
To identify species
To predict characteristics
To find evolutionary links
What are the three domains?
Archaea
Bacteria
Eukarya
Define ‘species’
A group of organisms that are able to reproduce to produce fertile offspring
What were animals classified on before the kingdom system?
Physical characteristics
What is binomial nomenclature?
A scientific name consisting of the genus and the species
When Aristotle classified organisms how did he do so?
Plants and Animals
Plants- every living thing that did not move or eat or that continued to grow throughout life
Animals- everything that moved, ate, and stopped growing at a certain size
What are the 5 kingdoms in Linnaeus’ system?
Prokaryotae Protoctista Fungi Plantae Animalia
What are the 3 general features of a prokaryotae?
Unicellular
No nucleus or membrane bound organelle
No visible feeding mechanism
Give an example of a prokaryotae
Bacteria- E coli
Explain the cellular structure of a protoctist
Unicellular
A nucleus and other membrane bound organelles
Some have chloroplasts
How do protoctists move?
Cillia, flagella or amoeboid mechanisms. However some are sessile.
How are nutrients acquired in protoctists?
Some are autotrophic
Some are heterotrophic
Some use both
Give two examples of a protoctist
Paramecium and Amoeba
Explain the cellular structure of fungi
Unicellular or multicellular
A nucleus and other membrane bound organelles
No chloroplasts
How do fungi move?
They have no mechanism for locomotion
What is a fungi made of?
A body or mycelium made of threads or hyphae
How do fungi acquire nutrients?
Saprophytic feeders
Give 3 examples of fungi
Mushrooms, Moulds and Yeast
Explain the cellular structure of plants
Multicellular
A nucleus and other membrane bound organelles
Chlorophyll
How do plants move?
Don’t tend to move however gametes of some plants move via cillia or flagella
How do plants obtain nutrients?
Autotrophic so acquire nutrients via photosynthesis
How do plants store food?
As starch
Explain the cellular structure of animals
Multicellular
A nucleus and other membrane bound organelles
No chloroplasts
How do animals move
Aid of cillia, flagella, contractile proteins in form of muscular organs
How do animals obtain nutrients?
Heterotrophic feeders, obtain nutrients via ingestion
What characteristics does Woese’s system use to classify?
Differences in sequences of nucleotides in cell’s ribosomal RNA
Cell’s membrane lipid structure
Sensitivity to antibiotics
What form of rRNA and have different ribosomes do Eukarya have?
Ribosomes=80S
RNA polymerase contains 12 proteins
What form of rRNA and have different ribosomes do Archaea have?
70S ribosomes
RMA polymerase has between 8 and 10 proteins
What form of rRNA and have different ribosomes do Bacteria have?
70S ribosomes
RNA polymerase has 5 proteins
What are the 6 kingdoms in Woese’s system?
Archaebacteria Eubacteria Protoctista Fungi Plantae Animalia
What is specific about Archaebacteria?
Ancient bacteria that live in extreme environments
What is phylogeny?
The name given to evolutionary relationships between organisms
What does phylogeny show?
Reveals which groups organisms are particularly closely related to
How closely organisms are related to each other
What does a phylogenetic tree show?
Branched diagrams which show that different species have evolved from a common ancestor
How are phylogenetic trees produced?
Looking at similarities and differences in species’ physical characteristics and genetic make up.
Give 2 advantages of phylogenetic classification
Phylogeny creates a continuous tree and therefore data is not forced into groups
Doesn’t have a hierarchal nature
What is evolution?
The theory that describes the way in which organisms evolve, or change, over many years as a result of natural selection
What is the theory of uniformitarianism?
The Earth was shaped by physical forces such as sedimentation, erosion and depostion
Who came up with the theory of uniformitarianism?
James Hutton
Which animal did Darwin investigate evolution on? What did he see?
Finches, variations in the beaks and claws.
What did theory did Darwin propose?
The theory of evolution by natural selection
Give 3 different ways that the process of evolution can be studied
Palaeontology
Comparative Anatomy
Comparative Biochemistry
What is the fossil record?
Different layers of rock are formed over time
The top strata is the newest and the bottom strata is the oldest
The newest fossils are found in the top
Fossils look different depending on their time period
Give 4 pieces of evidence for evolution provided by the fossil record
Oldest fossils have more simple organisms, newer fossils have more complex organisms
Sequence which organisms are found matches ecological links
Fossils can show how closely related ancestors are linked
Fossils allow the relationship between extinct and living organisms to be investigated
Give 3 reasons why the fossil record is incomplete
Soft-bodied organisms decompose quickly
Conditions for fossilisation aren’t always present
Fossils have been destroyed by tectonic activity
What is comparative anatomy?
The study of similarities and differences in the anatomy of different living species
What is a homologous structure?
A structure that appears superficially different in different organisms but has the same underlying structure
What is divergent evolution?
The process of from a common ancestor different species evolve with a different set of adaptive features.
When does divergent evolution occur?
Closely related species diversify to adapt to new habitats as a result of migration or loss of habitat
What is comparative biochemistry?
The study of similarities and differences in the proteins and other molecules that control life processes
What does the hypothesis of neutral evolution state?
The most variability of structure of a molecule does not affect its function
How do scientists compare when two species last shared a common ancestor?
The number of differences that exist are plotted against the rate at which molecule undergoes neutral base substitution.
How are relationships between ancient species compared?
Ribosomal RNA and fossil records
