Flashcards in Classification and Evolution Deck (84)
Define the term “classification”.
The act of arranging organisms into groups based on their similarities and differences.
Define the term “taxonomy”.
The study of classification.
Define the term “taxonomic group”.
The hierarchical groups of classification: domain, kingdom, phylum, class, order, family, genus, species.
Define the term "hierarchical”.
Arranged so that entity is subordinate to a different to a different entity.
Define the terms “phylogeny".
The evolutionary relationships between organisms.
List the seven taxonomic groups, in order, from the broadest to the smallest.
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
Name the taxonomic level that has been added above kingdom.
Give 3 reasons why scientists classify organisms.
To identify species - by using defined systems of classification the species an organism belongs to can be easily identified.
To predict characteristics - if several members of a group have a specific characteristic it is likely other species in that group will have the same characteristics.
To find evolutionary links - species in the same group probably share characteristics as they have evolved from a common ancestor.
Define the term “species”.
A group organisms that are able to reproduce and produce fertile off spring.
Explain why horses and donkeys are separate species, and why mules are not given a scientific name and are not a separate species.
Horses and donkeys cannot produce fertile offspring. Mules are the offspring of donkeys and horses and they are infertile because their cells contain an odd number of chromosomes. Because they are infertile they are not classified as a species, and so are not given a scientific name.
Define the term “scientific name".
The taxonomic name of an organism, that consists of the genus and species.
Define the terms“binomial nomenclature”.
The scientific naming of a species with a latin name made of two parts, the first indicating the genus and the second indicating the species.
Define the term “generic name”.
The first word that indicates the organism's genus.
Define the term “specific name”.
The second word that indicates the organism's species.
State the conventions used in writing scientific names.
Written in lower case and in italics or underlined. The first letter of the genus name is capitalized.
Name the 5 kingdoms and give examples of the organisms they contain.
moulds, yeasts, mushrooms
fish, reptiles, birds
Describe the characteristic features of each of the 5 kingdoms: Prokaryotae
- no nucleus or any membrane bound organelles
- ring of naked DNA
- small ribosomes
- no visible feeding mechanism
- nutrients are absorbed through cell walls or produced internally by photosynthesis.
Describe the characteristic features of each of the 5 kingdoms: Protoctista
- mainly unicellular
- contains nucleus and other membrane bound organelles
- some are sessile, but others move by cilia, flagella or amoeboid mechanisms.
- nutrients are acquired by photosynthesis so they are autotrophs, or by ingestion of other organisms meaning they could also be heterotrophs.
- Some could be parasites.
Describe the characteristic features of each of the 5 kingdoms: Fungi
- unicellular or multicellular
- contains nucleus and other membrane-bound organelles.
- cell wall mainly composed of chitin.
- No chloroplasts or chlorophyll.
- Saprotrophic nutrition (absorbing substances from dead or decaying organisms) .
- no mechanisms for locomotion
- most have a body or mycelium of threads of hyphae
- Some are parasitic
- Most store glucose as a glycogen
Describe the characteristic features of each of the 5 kingdoms: Plantae
- a nucleus and other membrane bound organelles including chloroplasts
- a cell wall mainly composed of cellulose
- all contain chlorophyll
- most do not move, although gametes of some plants move using cilia or flagella.
- nutrients are acquired by photosynthesis so they are autotrophic feeders.
- store food as starch
Describe the characteristic features of each of the 5 kingdoms: Animalia.
- nucleus and other membrane organelles but no cell walls
- no chloroplasts
- move with the aid of cilia, flagella or contractile proteins, sometimes in the form of muscular organs.
- nutrients are acquired by ingestion, they are heterotrophic feeders.
State the 3 domains of life and the 6 kingdoms that the three-domain system uses.
3 domains: Bacteria, Archae, Eukayra,
6 kingdoms: Animalia, Eubacteria, Protoctista, Plantae, Fungi, Archae bacteria.
Describe the characteristic features of each of the 3 domains: Eubacteria (bacteria)
- 70s ribosomes
- RNA polymerase contains 5 proteins
Describe the characteristic features of each of the 3 domains: Archaea
- 70s ribosomes
- RNA polymerase of different organisms contains 8-10 proteins
Describe the characteristic features of each of the 3 domains: Eukarya
- 80s ribosomes
- RNA polymerase contains 12 proteins
Describe the evidence used to create the “Three Domain System” of classification.
- Scientists can discover evolutionary relationships between organism by comparing DNA and protein structure.
- These observations are used to categorise organisms
Define the term “phylogeny”.
The study of living organisms based on their evolutionary relationships.
Define the term “phylogenetic tree"
A diagram used to represent evolutionary relationships between organisms. Shows common ancestors.
Define the term “sister group”
Two descendants which are split from the same node are called sister groups.