classification and evolution Flashcards
give the taxonomic family
axonomic Hierarchy:
1. Domain – 3 domains: Archaea, Eubacteria and Eukaryotae
2. Kingdom – 5 kingdoms: Plantae, Animalia, Fungi and Protoctista are all eukaryotes (have a nucleus).
The kingdom Prokaryotae are all single celled organisms that don’t have a nucleus.
3. Phylum – subdivision of kingdom, a phylum contains groups of organisms with same body plan (e.g.
possession of backbone).
4. Class – group of organisms that all possess the same general traits (e.g. number of legs).
5. Order – subdivision of class using additional information (e.g. the class mammal is divided into order
Carnivora and order Herbivora).
6. Family – group of closely related genera (e.g. within order Carnivora, ‘dog’ and ‘cat’ families).
7. Genus – a group of closely related species.
8. Species – the basic unit of classification, members show some variation but are essentially the same.
why do we use latin for binomial mnaming system
re species were identified by a common name, however:
- The same organism may have different common names in different parts of a country/the world.
- Translation of languages may give different names.
- The same common name may be used for different species in other parts of the world.
Latin is the universal language, avoiding potential confusion by using common names.
(genus in upper case)
Biological definition of species:
A group of organisms that can freely interbreed to produce fertile offspring.
- doesn’t work for organisms only known as fossils, and organisms that reproduce asexually
Phylogenetic definition of species
A group of individual organisms that are similar in appearance, anatomy,
physiology, biochemistry and genetics.
why we cant use observable features as final classification system
Used in early classification systems, however don’t correctly classify things. Animals that move in water,
move in air, and move on land were separated. However, this means fish and turtles, birds and insects,
mammals and frogs are all grouped together. Observable features have the drawback that they are limited
to what can be seen
why were fungi were originally classified as plants
Fungi were originally classified as plants, their hyphae grow
like roots, however they don’t photosynthesise and digest organic matter and absorb nutrients.
how did we classify the five kingdom through just obsevable features
Electron microscopes reveal further detail inside cells allowing for more accurate classification. The fivekingdom classification are still based on observable feature of their anatomy, but at a microscopic level.
what system has replaced the 5 kingdom system
5 Kingdom system – now replaced with 3 domain (as Prokayotae are now Eubacteria and Archaea):
what feature does Prokaryotae have ?and example
No nucleus, loop of naked DNA (not in chromosomes with histone
proteins), no membrane-bound organelles, 70S ribosomes,
unicellular – smaller than eukaryotes, free-living or parasitic
EX Bacteria
what feature does Protoctista have? and example
Single-celled or simple multicellular (algae), variety of forms (they
are group as they don’t qualify to be in the other 4 kingdoms),
show plant-like and animal-like features, all methods of nutrition
EX Algae, protozoa
What feature does the fungi have? give example
Single-celled (yeasts) or have a mycelium consisting of hyphae,
chitin cell wall, multinucleate cytoplasm, saprotrophic – cause
decay of organic matter and absorb substances from them, by
secreting extracellular enzymes.
EX Moulds, yeasts,
mushrooms.
what feature does Plantae kingdom have?
Multicellular, cellulose cell walls, contain chlorophyll and can
photosynthesise, autotrophic – absorb simple molecule and build
them into larger molecules (i.e. produce own food).
EX Mosses, ferns,
flowering plants
what feature does Animalia have?and example
Multicellular, no cell walls, usually able to move around,
heterotrophic – digest large organic molecules for absorption.
EX Mammals, reptiles,
birds, insects etc.
whats a convergent evolution.and why does it disprove the observable classification
Observable features are largely successful, however since organisms adapt to their environment, it is
possible that two unrelated species adapt in similar ways and look similar – convergent evolution.
whats an Embryological evidence
Similarities in the early stages of an organisms’ development
whats an Anatomical evidence
Similarities in structure and function of different body parts
whats an Behavioural evidence
Similarities in behaviour and social organisation of organisms.
how does the sequence of cytochrome C help in identifying how living things are closely related to each other
A protein called cytochrome C is used in respiration, so all living things have it, but the protein isn’t
identical in every species. The sequence of amino acids in cytochrome c is what varies. The more similar
the sequence of amino acids of cytochrome C, the more closely related the species are likely to be.
Example: Humans and chimpanzees have identical cytochrome c, but different protein than fish.
how does the sequence of DNA help in identifying how living things are closely related to each other
Another biological molecule found in all living organisms, it provides the universal genetic code – a
sequence of DNA codes for the same sequence of amino acid in an organism. Random mutations cause
the DNA sequence to change. The more similar the sequence in a part of the DNA, the more closely
related the species are – this is the most accurate way to demonstrate how closely related species are
