Classification & Evolution Flashcards
What are the 7 taxonomic groups?
Kingdom Phylum Class Order Family Genus Species
Why do scientists classify organisms?
- To identify species
- To predict characteristics
- To find evolutionary links
What are species?
A group of organisms that are able to reproduce to produce fertile offspring
What is a mule/hinny?
Infertile offspring - not a species
Why are mules infertile?
Their cells contain an odd number of chromosomes. This means that meiosis and gamete production cannot take place correctly as all chromosomes must pair up
What were the issues before classification systems were used?
- Organisms may have more than one common name
- Different names in different languages
- Common names don’t provide information about relationships between organisms
What is binomial nomenclature?
The system in which two terms are used to denote a species of living organism
What does the first word of the species name indicate?
The genus
What does the second word of the species name indicate?
The specific name - organism’s species
How should an organism’s scientific name be presented?
- Italics
- Handwritten = underline name, lowercase with the exception of the first letter of genus’ name
What are the 5 kingdoms?
Prokaryotae Protoctista Fungi Plantae Animalia
How are organisms classified as prokaryotae?
- Cell type = prokaryotic
- Body organisation = unicellular
- Type of nutrition = autotrophic/heterotrophic
- No membrane-bound organelles
- E.g. bacteria
How are organisms classified as protoctista?
- Cell type = eukaryotic
- Body organisation = unicellular
- Type of nutrition = autotrophic/heterotrophic
- Membrane-bound organelles present
- E.g. algae
How are organisms classified as fungi?
- Cell type = eukaryotic
- Body organisation = multicellular
- Type of nutrition = heterotrophic
- Membrane-bound organelles present
- E.g. yeast
How are organisms classified as plantae?
- Cell type = eukaryotic
- Body organisation = multicellular
- Type of nutrition = autotrophic
- Membrane-bound organelles present
- E.g. angiosperms
How are organisms classified as animalia?
- Cell type = eukaryotic
- Body organisation = multicellular
- Type of nutrition = heterotrophic
- Membrane-bound organelles present
- E.g. birds
What is the current classification system used by scientists?
Three Domain System - Carl Woese
When was the word ‘kingdom’ renamed ‘domain’?
1990
How are the organisms in the 3 different domains different?
Unique form of rRNA and different ribosomes:
- Eukarya: 80s ribosomes and RNA polymerase with 12 proteins
- Archaea: 70s ribosomes and RNA polymerase with 8-10 proteins
- Bacteria: 70s ribosomes and RNA polymerase with 5 protein sugar