3. Classification And Evolution Flashcards
(77 cards)
Need for classification
- for convenience
- Makes it easy to identify organisms
- Makes it easier to study organisms
- Allows us to see the relationships between organisms
Classification top to bottom
Domain, kingdom, phylum, class, order , family, genus, species
Domain
(archaea, eubacteria, eukaryotae)
Kingdom
plantae, animalia, fungi, protoctista, prokaryotae)
Phylum
whether or not they have a backbone) chordata = animals w/ backbones
Class
general traits e.g. number of legs + arms)
Order
depends on what they eat)
Family
closely related group within order)
Species biological definition
a group of organisms that can interbreed to produce a fertile offspring =
Phylogenetic definition of species
a group of individual organisms that are very similar in appearance, anatomy, physiology, biochemistry and genetics
Features of protoctista
- eukaryotic
- Aquatic
- Most unicellular
- Autotrophic or heterotrophic
Plant responses to defend themselves from herbivores:
- chemicals (phenols)
- Folding
- Stings
Autotroph
make their own nutrients
Heterotroph
organisms that eats other plants or animals for energy and nutrients
Q
Binomial naming system
- first name is always the genus
- Second part of the name is the species
- The first letter in the genus is a capital letter and the species is in lower case (it all is in italics) = allows everyone to use the same naming system which simplifies research
Advantage of binomial naming system
universal and helps know which genus it belongs to
Prokaryotae
have no nucleus
have a loop of DNA that is not arranged in linear chromosomes
• have naked DNA (DNA that is not associated with histone proteins)
• have no membrane-bound organelles
• have smaller ribosomes than in other groups
• have cells smaller than those of eukaryotes
• may be tree-living or parasitic (some cause diseases)
Protoctista
• are eukaryotic
• are mostly single celled (but many algae are multicellular)
• show a wide variety of forms (the only thing that all protoctists have in common is that they do not qualify to belong to any of the other four kingdoms!)
• show various plant-like or animal-like features
• are mostly free-living
• have autotrophic or heterotrophic nutrition - some photosynthesise, some ingest prey.
some feed using extracellular enzymes (like fungi do), and some are parasites
Fungi
• are eukaryotic
• can exist as single cells (called yeasts) or they have a mycelium that consists of hyphae
• have walls made of chitin
• have cytoplasm that is multinucleate
•are mostly free-living and saprophytic - this means that they cause decay of organic matter
Plantae
• are eukaryotic are multicellular
have cells surrounded by a cellulose cell wall
• are autotrophic (absorb simple molecules and build them into larger organic molecules)
• contain chlorophyll
Animalia
• are eukaryotic are multicellular
• heterotrophic (digest large organic molecules to form smaller molecules for absorption)
• are usually able to move around
How is genetic material in bacteria held?
- dna loop free in cytoplasm
- Not associated w histone
Defining features of eukarya
- nucleus
- DNA w histone
- Membrane bound organelles
Evidence to classify organisms
DNA, biological evidence, conversion evolution