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What is the binomial system?
A system that uses the genus name and the species name
Avoids confusion when naming organisms
What is classification?
Process of placing living things into groups
Why do we classify things?
- For convenience
- Make the study of living things more manageable
- Make it easier to identify organisms
- Helps to view the evolutionary relationships (phylogeny) between species
What is the order of the modern classification hierarchy?
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
What are the three domains?
- Archaea
- Eubacteria
- Eukarya
What are the five main kingdoms?
- Plantae
- Animalia
- Fungi
- Protocista
- Prokaryote
What is the kingdoms that possess a nucleus?
Plantae, Animalia, Fungi, protocista
What kingdom has no nucleus?
Prokaryote
Does it become easier or harder to classify new species' as you go down the taxonomy hierarchy?
As you go down the modern classification hierarchy, it becomes harder and harder to;
- Separate closely related species
- Place a species accurately
- Therefore a more and more detailed description is needed
What is the binomial naming system?
Using the genus and species names together
How can you tell the genus name of the binomial name?
Genus name will be;
- First name
- Have a capital letter
How must the binomial system be portrayed?
Stand out, either in,
- Italics (primary option)
- Underlined (secondary option)
Who devised the binomial naming system?
Carl Linnaeus
What occurred before the binomial name?
Common name system
What does binomial mean?
In two (parts)
Why was the common name system terrible, did not work well?
- Same organism may have a completely different common name is different parts of one country
- Different common names of the same species were used in different countries
Why were there an addition of different common names of the same species between countries?
Translation of languages/dialects gave many different names for the same species
What language was used to place species in the taxonomy?
Latin
What does using latin as the universal language for the taxonomy mean?
Avoids potential confusion between names for the same species (common names)
What is the biological definition of species?
A group of organisms that can freely interbreed to produce fertile offspring
What is the phylogenic definition of species?
A group of individual organisms that are very similar in;
- Appearance
- Anatomy
- Physiology
- Biochemistry
- Genetics
What was the old classification system based on?
- Appearance
- Anatomy
Did the old classification provide classification?
Yes, however mistakes were common
What, in the earliest attempts of classification, was the first classification system?
- Plant
- Animal
How were animals subdivided?
- Living and moving through air
- Living and moving in water
- Living and moving on land
Example of animals that were incorrectly group?
Everything; i.e. penguins and a giraffe, killer whale and squid, eagle and a mosquito
When was classification developed beyond observable features?
17th century, with the help of microscopes.
What was the general acceptance of kingdoms at the start of classification? (repeated question)
2 kingdoms only; plants and animals.
If you got this wrong, go and get some sleep
Where were single celled organisms grouped in?
Animals
What were fungi originally classified as?
Plants
What are the five kingdoms?
- Prokaryote
- Protoctista
- Fungi
- Plantae
- Animalia
What is the description of prokaryote that allows them to be classified?
- No nucleus
- Loop of DNA that is non-linear
- Naked DNA, not histone proteins
- No membrane-bound organelles
- Have smaller ribosomes than other groups
- Have cells smaller than eukaryotes
- May be free living or parasitic
What is the description of protoctists that allows them to be classified?
- Eukaryotic
- Mostly single celled but can be multicellular
- Show a variety of forms
- Show various plant-like or animal-like features
- Are mostly free living
- Have autotrophic and/or heterotrophic nutrition
- Commonality; do not qualify to belong to any of the other four kingdoms
What is the description of fungi that allows them to be classified?
- Eukaryotic
- Exists as single celled yeasts or they have a mycelium with hyphae
- Have walls made of chitin
- Have a cytoplasm that is multinucleate
- Mostly free living and saprophytic
What are yeasts?
Single celled fungi, reproduced by budding
What are saprophytic fungi?
Cause decay of organic matter
What is the description of plantae that allows them to be classified?
- Eukaryotic
- Multicellular
- Cells surrounded by a cellulose plant wall
- Autotrophic
- Contains chlorophyll
What is the description of animalia that allows them to be classified?
- Eukaryotic
- Multicellular
- heterotrophic
- Usually able to move around
Remember card (flip)
Remember to describe the differences between these five kingdoms, memorise.
What is convergent evolution?
Unrelated species evolve similar traits due to their similar environments even though they live in different parts of the world
What research allows more evidence to classify different species?
- Protein cytochrome C
- DNA
- Three domain classification
What can differences between biological molecules be used to study?
- Evolutionary relationships (Phylogeny)
- Evolution of a species
Where is cytochrome C used in?
Respiration
Do all organisms that respire use cytochrome C?
Yes
Is cytochrome C a protein that is identical in all organisms?
No, the primary structure of cytochrome C can vary between species to species
When comparing two cytochrome C proteins from two different species, what can we conclude?
- If sequences are the same, then the two species are closely related
- If the sequences are different, the two species are not closely related
What is the trend between cytochrome C of two species and differences between the amino acid primary structure sequence?
The more differences in sequences, the less closely related the two species are
Is the amino acid sequence of cytochrome C in humans and chimpanzees the same?
Yes
Is the amino acid sequence of cytochrome C in humans and the dogfish the same?
No, there are 11 differences in the primary structure of the human cytochrome C and the dogfish cytochrome C
What biological molecule provides genetic code? (easiest question you could answer)
DNA
What is a feature of DNA that can allow cross-referencing between the genetic codes of different species?
That DNA is universal
What are changes of bases in DNA?
Mutations
What is the trend between how closely related two species are and the differences between the DNA sequence of the two species?
- The more similar a sequence of DNA is compared to another sequence, the more closely related those two species are.
- The more differences of a sequence of DNA and another sequence of DNA, the less closely related those two species are
Which biological molecule is more accurate to study how closely two species are related, cytochrome C or DNA?
DNA
What new classification was introduced by Carl Woese? What was it based on?
Three domain classification; based on a detailed study of the ribosomal RNA gene
What evidence supports Carl Woese differences between bacteria and archaea?
Each have different structures of their ribosomes
What are the main differences between bacteria and archaea?
- Different cell membrane structures
- Different internal structures of the flagella
- Different enzymes (i.e. RNA polymerase)
- No proteins bound to the genetic material of bacteria (i.e. histone proteins)
- Different mechanisms for DNA replication and for synthesising RNA
What features does archaea share with eukaryotes?
- Similar enzymes (RNA polymerase) for synthesising RNA
- Similar mechanisms for DNA replication and synthesising RNA
- Production of some proteins than bind to their DNA
What part of the differences did Woese signify?
RNA and DNA mechanisms.
What is phylogeny?
The study of the evolutionary relationships between organisms
What are the two types of classifications?
1. Artificial classification
2. Natural classification
What are the features of artificial classification?
- Based on only a few characteristics
- Does not reflect any evolutionary relationships
- Provides limited information
- But it is stable
What group will closely related species be placed within?
A genus.
What group will multiple closely related genera be place in?
A family
What are ranked groups following each known as?
Hierarchy
What are the features of natural classification?
- Uses many characteristics
- reflects evolutionary relationships
- Provides a lot of useful information
- May change with advancing information
What does phylogeny involve?
Studying how closely related different species are
What is the term called for when species belong to one phylogenic group (i.e. a common ancestor)?
Monophyletic
Can common ancestors be regarded as some who lives in the present (today)?
Absolutely not.
Confused? If me and you are homo sapiens, we cannot say we evolved from gorillas. What we can say is that gorillas and humans evolved form the same common ancestor.
Still confused? In theory, yes, if you artificially preserved a common ancestor in a indefinite zoo that lived forever and let its other relatives of the same species live on to evolve to other species, you theoretically contradict common ancestors, however evolution is constant in nature therefore common ancestors cannot live in the present
In theory, does a snake and a human share a common ancestor?
Yes, around 300 to 400 million years ago
(you won't be asked this specific question in your exam)
Could I say, humans evolved from apes?
No, but apes and humans share a common ancestor
What is natural selection?
Explains how features of the environment applies a selective force on the reproduction of individuals in a population
Was the theory of evolution originally Darwins idea? What exactly did he do?
No, but Darwin displayed a mechanism to the world of the process
Why were people against Darwin and his proposed mechanism of the theory of evolution?
As during Victorian Britain, his theory went against religious belief
What was Darwins actual mechanism called?
(not a trick question, just use your common sense and what you learnt from GCSE)
Natural selection
Where did Darwin understand natural selection?
Galapagos islands
What made Darwin realise natural selection?
1. Found different variations of finches on each island
2. Concluded that one species of finch had arrived on the islands and then formed different species per island
Who is Russel Wallace?
A naturalist who independently came to the same conclusion as Darwin
What was Darwins book called?
The Origin of Species
What four observations did Darwin make?
1. Offspring generally appear similar to their parents
2. No two individuals are identical
3. Organisms have the ability to produce large numbers of offspring
4. Populations in nature tend to remain fairly stable in size
What are Darwins conclusion that relate to survival of the fittest?
- There is a struggle to survive
- Better adapted individuals survive and pass on their characteristics
- Over time, a number of changes give rise to a new species
What are the two main types of evidence for evolution?
- Fossil evidence
- Biological molecules evidence
What facts do fossils show?
- World was inhabited by species that were different from those present today
- Old species have died out and new species have risen
- New species that have appeared are similar to the older species found in the same place
Why were more modern species surviving moreso than the old species in fossils?
The new species has variations that were better adapted to the environment
What differences usually occurred between old and new species?
Many fossil species were much larger than modern species
How are biological molecules an example as evidence for evolution?
- All organisms in the world have the same or similar biological molecules
- Two closely related species will have separated recently if their biological molecules are identical/similar
- As species separate with differences, biological molecules are likely to be different
- Protein difference correlates with how different two species are (i.e. cytochrome C)
What does species having the same/similar biological molecules suggest?
All species in the world originated from one original ancestor
How can DNA be used as evidence for evolution?
Number of similarities between gene sequences shows how closely related two species are
In percentage, how does comparison of human DNA and other primates show?
- Chimpanzees differ 1.2% of humans
- Gorillas differ 1.6% of humans
- Baboons differ 6.6% of humans
What is continuous variation?
Variation where there are two extremes and a full range of values in between
What is discontinuous variation?
Where there are distinct categories and nothing in between
What is environmental variation?
Variation caused by response to environmental factors, i.e. light intensity
What is genetic variation?
Variation caused by possessing a different combination of alleles
What is interspecific variation?
Differences between species
What is intraspecific variation?
Variation between members of the same species
What is variation?
Presence of variety; differences between individuals
How can twins appear different?
- Subsequent replication of DNA and cell divisions may have introduced changes to the DNA showing genetic variation
- Slight environmental differences in the womb or after birth from the environment can show physical variation
What variation can there be within a intraspecies?
- Eye colour
- Hair colour
- Skin colour
- Nose shape
Is genetic diversity directly correlated to intraspecific variation?
Yes
In continuous variation, where are most individuals close to?
(a level maths people; think normal distribution!)
The mean value
Note 
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