Classification & Evolution/Biodiversity Flashcards
What are living things grouped together based on?
- Observable characteristics (gross & microscopic)
- Structure (biochemistry including DNA, Proteins, rRNA)
What is classification?
The grouping of organisms based on their structure and characteristics.
Why do scientists classify organisms? (4 reasons)
- To identify species
- To predict characteristics
- To find evolutionary link
- Make the study of living things more manageable
What are the 7 “taxonomic groups” in the Linnaean Classification system?
Kingdom Phylum Class Order Family Genus Species
What is another name for “naming species”?
Binomial naming system
What system came after the Linnaean classification system?
The three-domain system
Who created the Linnaean classification system?
Carl Linnaeus
Who created the three domain system?
Carl Woese
What 3 domains are there in the 3-domain-system?
Archaea
Bacteria
Eukaryota
What is Archaea?
Primitive bacteria that usually lives in extreme conditions
What is Bacteria?
True Bacteria, such as E. Coli and Salmonella
What is Eukaryota?
Protists, fungi, plants and animals
What is included in the 5 kingdom classification?
Prokaryotes:
Prokaryotae (bacteria)
Eukaryotes:
- Proctista (the unicellular eukaryotes)
- Fungi (yeasts, moulds and mushrooms)
- Plantae (the plants)
- Animalia (the animals)
Describe features of Prokaryotae
- Unicelluar
- No nucleus or other membrane-bound organelles
- Nutrients are absorbed through the cell well
Examples - E. Coli, Bacillus Anthracis
Describe Protoctista
- Unicelllar
- Some contain chloroplasts
- Some are immobile, others have cilia, flagella or ameboid mechanism
- Nutrients acquired by photosynthesis
(autotrophic feeders), ingestion of other organisms (heterotrophic feeders) of both - some are parasitic.
Examples - Paramecium and Amoeba
Describe Fungi
- Unicellular or Multicellular
- A nucleus, other membrane-bound organelles and a cell wall mainly composed of chitin
- no chloroplasts
- No mechanisms or locomotion
- nutrients acquired from decaying matter (saprophytic)
- Most store their food as glycogen
Examples: mushrooms, moulds and yeasts
How many Plantae species are there?
250,000
Describe Plantae
- Multicellular
- Nucleus, chloroplasts and cell wall mainly composed of cellulose
- All contain chlorophyll
- Most don’t move
- Nutrients acquired via photosynthesis (autotrophic feeders)
- store food as starch
Examples: roses, tree (e.g. oak) and grasses
How many Animalia species are there?
1,000,000
Describe Animalia
- Largest kingdom
- Multicellular
- A nucleus and other membrane-bound organelles (no cell walls)
- No chloroplasts
- Move with the aid of cilia, flagella, contractile proteins and sometimes muscular organs
Examples: mammals, reptiles, birds, insects
Describe the ribosomes of Eukarya
- RNA polymerase contains 12 proteins
Describe the ribosomes of Archaea
- RNA polymerase contains 8-10 proteins
Describe the ribosomes of Bacteria
- DNA polymerase contains 5 proteins
What is the difference between bacteria and archaea?
- Bacteria have peptidoglycan cell wall whereas archaea do not
- They are also not closely related
What is phylogeny?
Evolutionary relationships between organisms.
What is a phylogenetic tree?
A diagram used to represent the evolutionary relationship between organisms. They can show how different species have evolved from a common ancestor.
- They are produced by looking at similarities and differences in species’ physical characteristics and genetic make up. Much of the evidence has been gained from fossils.
What are the advantages of phylogenetic classification?
- Can be used to confirm/change Linnaeus classification groups
- Phylogeny produces a continuous tree, which means scientists don’t need to put it in a specific group that might not fit.
- The hierarchical nature of Linnaeus classification can be misleading as it implies that different groups are the same rank.
What is the main difference between early classification systems and systems based on phylogeny?
Early classification doesn’t consider evolution, simply observable features and biochemistry
Describe the advantages of phylogenetic classification over the Linnaean system
Phylogenetic classification shows the time and evolution of organisms, whereas Linnaean classification doesn’t.
What is evolution?
The way which organisms evolve or change, over many years as a result of natural selection.
What is Darwin’s theory of evolution
Darwin believed evolution was a slow process - one in which small changes gradually accumulate over very long periods of time.
What book did Darwin publish?
“On the origin of species”
Why was Darwin’s theory of evolution rejected?
- Conflict with religion
- Conflicted with the idea that God created all animals
- Implied humans are a type of ape
What are the 3 sources scientists use to study the process of evolution?
- Palaeontology
- Comparative anatomy
- Comparative biochemistry
What is Palaeontology?
The study of fossils and the fossils record
What is comparative anatomy?
The study of similarities and differences between organisms’ anatomy
What is comparative biochemistry?
Similarities and differences between the chemical makeup of organisms
How does palaeontology provide evidence for evolution?
The sequence in which fossils are found support the theory, as plant fossils are older than animal fossils. This is consistent with the fact that animals require plants to survive.
How does comparative anatomy show evidence for evolution?
Homologous structures are structures that appears superficially different, as they may perform different functions, but have the same underlying structure.
- This provides evidence for divergent evolution.
How is comparative biochemistry evidence for evolution?
Study similarities and differences in the order of DNA bases.
What is drug resistance?
When bacteria were exposed to this antibiotic, resistant individuals survived and reproduced, passing the allele for resistance on to their offspring. Non-resistant individuals died. Over time the number of resistant individuals in the population increased.
What are the stages of natural selection?
- Each species shows variation.
- There is competition within each species for food, living space, water, mates “IDENTIFY THE SELECTION PRESSURE”
- The “better adapted” members of these species are more likely to survive “advantageous alleles”
- These survivors will pass on their better genes to their offspring who will also show this beneficial variation - many generations
What is variation?
Differences in characteristics between organisms
What is variation between species
- inter specific variation