evolution of classification Flashcards
What is an example and features of the Prokaryotae kingdom? (2)
Bacteria
Features: Prokaryotic, unicellular, no nucleus (DNA is free), smaller ribosomes, less than 5μm
What is an example and features of the Protictista kingdom? (2)
Example: Algae, Protozoa
Features: Eukaryotic, usually live in water, unicellular or simple multicellular organisms
What is an example and features of the Fungi kingdom? (2)
Example: Moulds, Yeast, Mushrooms
Features: Eukaryotic, chitin cell wall, saprotrophic (absorb substances from dead/decaying organisms), single-celled or multicellular organisms
What is an example and features of the Plantae kingdom? (2)
Example: Mosses, Ferns, Flowering plants\n\n-
Features: Eukaryotic, multicellular, cellulose cell walls, photosynthetic, contain chlorophyll, autotrophic/photoautotrophic (produce own food using light)
What is an example and feature of the Animalia kingdom? (2)
Example: Nematodes, Molluscs, Insects, Fish, Reptiles, Mammals, Birds
Features: Eukaryotic, multicellular, no cell walls, heterotrophic (consume plants and animals)
What were early classification systems based on, and what was their limitation? (2)
Early classification systems used observable features
But they might not accurately show how related organisms are
What do modern classification systems use alongside observable features? (4)
Molecular evidence (DNA and proteins)
Embryological evidence (development stages)
Anatomical evidence (body structure and function)
Behavioural evidence (behaviour and social organisation)
How is molecular evidence used in classification? (3)
By comparing DNA base sequences and amino acid sequences in proteins (e.g. cytochrome C)
Which shows the degree of relatedness between organisms
The more similar the sequences, the more closely related the species are
What is embryological evidence in classification? (2)
It involves comparing the similarities in the early stages of an organism’s development
To determine how closely related organisms are
What is anatomical evidence in classification? (2)
It compares the structure and function of body parts in different organisms
To assess their relatedness
What is behavioural evidence in classification? (2)
It involves comparing the similarities in behaviour and social organisation among organisms
To help classify them
What system has replaced the five-kingdom classification system? (1)
Three-domain system
How did the old five-kingdom system classify organisms? (2)
Into five groups
Plant, Animal, Fungi, Protista, and Prokaryotae (Monera)
What are the three domains in the modern classification system? (3)
Eukarya
Archaea
Bacteria
Which organisms are placed in the Eukarya domain? (2)
Organisms that contain a nucleus
Including four of the five kingdoms (Plant, Animal, Fungi, and Protists)
Why were organisms in the kingdom Prokaryotae separated into two domains in the new system? (2)
Because new evidence showed that Archaea and Bacteria evolved separately
Archaea are more closely related to Eukarya than Bacteria
What molecular evidence supports the three-domain system? (2)
RNA polymerase is different in Bacteria and Archaea
Archaea (but not Bacteria) have similar histones to Eukarya
What cell membrane evidence supports the three-domain system? (2)
The bonds in lipids in the cell membranes of Bacteria and Eukarya are different
The development and composition of flagellae differ between the domains
