Flashcards in Ch. 10.2 : The Five Kingdoms Deck (13):
What are the traditional five kingdoms?
The prokaryotes :
Prokaryote ( bacteria )
The eukaryotes :
Protoctista ( unicellular eukaryotes )
Fungi ( eg yeasts, moulds and mushrooms )
Plantae ( the plants )
Animalia ( the animals )
What are the general features of prokaryotes ?
No nucleus or other membrane bound organelles - a ring of 'naked' DNA - small ribosomes
No visible feeding mechanism - nutrients are absorbed through the cell walk or produced internally by photosynthesis
What are the general features of protoctista ?
( Mainly ) unicellular
A nucleus and other membrane bound organelles
Some have chloroplasts
Some are sessile, but others move by cilia, flagella or by amoeboid mechanisms
Nutrients are acquired by photosynthesis ( autotrophic feeders ), ingestion of other organisms ( heterotrophic feeders ) , of both - some are parasitic
What are the general features of fungi ?
Unicellular or multicellular
A nucleus and other membrane bound organelles and a cell wall mainly composed of chitin
No chloroplasts or chlorophyll
No mechanisms for locomotion
Most have a body or mycelium made of threads or hyphae
Nutrients are acquired by absorption - mainly from decaying material - they are saprophytic feeders - some are parasitic
Most store their food as glycogen
What are the general features of plantae ?
A nucleus and other membrane bound organelles including chloroplasts , and 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 - they are autotrophopic feeders - organisms that make their own food
Store food as starch
What are the general features of animalia ?
A nucleus and other membrane bound organelles ( no cell walls )
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
Food stored as glycogen
Why are classification systems changing?
Originally they were based on observable features.
Through the study of genetics scientists are now able to study the evolutionary relationships between organisms.
This can be done by comparing DNA and proteins, which affects the observable features and characteristics.
What is the classification system we now use?
Three Domain System - Carl Woese
Renamed to Domain in 1990
Describe the three Domain system
There are three domains and six kingdoms. The three domains are Archaea, Bacteria and Eukarya.
What are the differences in the three domains?
Eukarya - have 80s ribosomes
- RNA polymerase contains 12 proteins
Archaea - have 70s ribosomes
- RNA polymerase of different organisms contains between 8 and 10 proteins and is very similar to eukaryotic ribosome
Bacteria - have 70s ribosomes
- RNA polymerase contains 5 proteins
What is the difference in kingdoms in Domain and the traditional 5 kingdoms?
In Domain, the prokaryote kingdom becomes divided into Archaebacteria and Eubacteria, so there are 6 kingdoms.
Describe Archaebacteria and Eubacteria and their differences
Archaebacteria : Can live in extreme conditions e.g hot thermal vents, anaerobic conditions and highly acidic environments
Eubacteria : Found in all environments. Most bacteria are Eubacteria
Their chemical makeup is different