Domains & Kingdoms Flashcards
what are the five kingdoms?
• Monera, protista, plantae, fungi, animalia. prokaryotes used to be in monera
what are the three domains? why were they proposed?
bacteria, archaea, eukarya some prokaryotes (archaea) shared traits with eukaryotes - need for another group
describe the Linnean hierarchy from most inclusive to least
kingdom, phylum, class, order, family, genus, species
remember the indentation when writing it
how would scientists change their names?
• Scientists would change their name into a Latinised version
what is more exclusive than kingdom?
domain
what is systematics? who proposed it?
• Study of biodiversity
• Study of evolutionary relationships / genealogy
William Henning proposed systematics can be done via ancestor- descendant relationships
what is a cladogram?
- A branching diagram depicting the evolutionary relationships of groups of organisms
- Usually dichotomously branched
- Diagram representing clades
what is a clade? nodes? terminal taxa?
• A monophyletic group of organisms sharing homologous features derived from a common ancestor
• Terminal taxon/taxa
• The areas of dichotomous branching are called nodes - represents most recent common ancestor
Clade includes most common ancestor and all its descendants
what is monophyletic?
A taxon in which all species share a most recent common ancestry and all species derived from that common ancestor must be included
what is polyphyletic?
derivation of a taxon from two or more ancestral sources
what is paraphyletic?
a taxon where all species share a common ancestor but not all species derived from that common ancestor are included
bacteria and archaea are paraphyletic
in the 5 kingdom system monera is paraphyletic
is taxonomy complete?
• Clearly taxonomy at the highest level is a work in progress
There will be much more research before there is anything close to a new consensus for how the three domains of life are related and how many kingdoms there are
what is the criteria for a gene looked at for phylogeny?
• 1. Because you want to build a tree that contains representa-tives from all major groups of life, the gene must be uni-versal: it must be present in all forms of life.
• 2. You want the gene sequence to be strongly conserved. Although it is essential that there is variation in the se-quence, too much variation will make it hard to compare the sequences between two distantly related organisms. Genes critical for the survival of the cell are ideal for this purpose.
3. You want the gene to be fairly long, because the longer the gene sequence, in essence, the more information it con-tains.
what did carl R woese discover?
he gene that codes for the RNA molecule that makes up the small subunit of the ribosome (rRNA) was an ideal candidate. Ribo-somes, the organelles that that translate messenger RNA mole-cules into proteins (see Section 12.4), are found in all forms of life and are remarkably similar in their structure.
how did carl’s work change the tree of life?
Starting in 1977, the phylogenetic tree that Carl Woese and his colleagues built based on rRNA sequences completely changed how scientists saw the tree of life (Figure 21.24). Instead of the old five kingdoms, the rRNA data clearly delineated only three primary lineages of organisms, which we refer to as domains: Bacteria, Archaea, and Eukarya.
