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
What is variation within a species called?
Intraspecific variation
What are 2 causes of variation?
- Genetics
- Environment
What is genetic variation?
Differences in the genetic material an organism inherits from its parents leads to genetic variation.
What is environmental variation?
The environment in which the organism lives, causing environmental variation.
What are the genetic causes of variation?
- Alleles
- Mutations
- Meiosis
- Sexual
- Chance
What is environmental cause of variation?
The way an environment can affect an organism’s characteristic
What type of variation is height?
Both genetic and environmental
What type of variation is skin colour?
Genetic
What are adaptions?
Characteristics that increase an organism’s chance of survival and reproduction in its environment
What are the three types of adaptions?
- Anatomical adaptions
- Behaviour adaptions
- Physiological adaptions
What is an anatomical adaption?
Physical features (internal and external)
What is a behavioural adaption?
The way an organism acts - either inherited or learnt from their parents
What is a physiological adaption?
Processes that take place inside an organism
Give 4 examples of anatomical adaptions
- Body covering - feathers, shells
- Camouflage - white fur
- Teeth - carnivores like tigers have sharp canines
- Mimicry - appearance or sound copied by a harmless organism
Give 3 examples of behavioural adaptions
- Survival behaviours - playing dead when seen
- Courtship - animals may exhibit courtship to increase chance of finding a mate and reproduction
- Seasonal behaviour - migration & hibernation
What are the two categories behavioural adaptions can fall into?
- Innate (instinctive behaviour)
- Learned behaviour
What are 3 physiological adaptions?
- Poison production - produce venom
- Antibiotic production - bacteria can produce antibiotics to kill other species
- Water holding - allows survival in the desert
What are analogous structures?
Structures that have been adapted to perform the same function but have different genetic origin
What is homologous structures?
A structure that appears different in different organisms, but have the same underlying structure.
What is convergent evolution?
When unrelated species begin to share similar traits
What are 3 factors that affect biodiversity
- Deforestation
- Agriculture (monoculture)
- Climate change
How does deforestation affect biodiversity?
- Reduces trees which lower number of habitats.
- This will result in a reduced species diversity
How does agriculture affect biodiversity?
- Removal of hedgerows remove habitats
- Use of pesticides reduces species diversity
- monoculture leads to massive loss of species diversity
How does climate change affect biodiversity?
- Melting of ice caps leads to extinction of plants and animals in these regions
- Rising sea levels reduces available terrestrial habitats
- High temperatures lead to some plant species failing to survive.
- Insect cycle will change which could spread disease.
What are the three types of biodiversity?
- Species
- Genetics
- Habitats
What are factors that increase genetic biodiversity
Interbreeding
Mutations
What factor decreases genetic biodiversity?
Selective breeding (natural selection)
What is a polymorphic gene?
A gene in which multiple alleles exist.
What is the equation for the proportion of polymorphic gene loci?
Proportion of polymorphic gene loci = number of polymorphic gene loci/total number of loci
What are 3 reasons for maintaining biodiversity?
- Economic
- Ecological
- Aesthetic
What are aesthetic reasons for maintaining biodiversity
- Enriches our lives
- Natural world provides inspiration for the arts
- Help recovery from stress and injury
What are economic reasons for maintaining biodiversity?
- Desertification could impact the ability to grow crops
- Removal of resources may lead to collapse of industry
- Non-discovered plants species may have medicinal uses
- Continuous monoculture results in soil depletion
- Areas with high biodiversity can attracts tourists
What are ecological reasons for maintaining biodiversity?
- All organisms are interdependent for survival
- “Keystone species” essential to maintain species richness and evenness, as they affect their environment massively.
What is in situ conservation
Conservation which takes place within the natural habitat
What is ex situ conservation
Conservation which takes place out of the natural habitat
What are two examples of in situ conservation
Wildlife reserves
Marine conservation zones
What are examples of ex situ conservation
- Botanic gardens
- Seed banks
- Captive breeding programmes
What can wildlife reserves include?
- Feeding animals
- restricted human access
- controlled grazing
- halting succession
What are some reasons organisms born in captivity may not be suitable for release in the wild?
- Disease (may introduce resistance)
- Behaviour (lack of learned behaviour)
- Genetics (can’t interbreed)
- Habitat (may have limited space)
What do conservation agreements do?
Regulate trade of species and their products.
What is an example of an international conservation organisation?
CITES (Convention on International Trade in Endangered Species)
What do CITES do?
Regulate the international trade of wild plant and animal specimens AND THEIR PRODUCTS
What did the Rio Convention of Biological Diversity aim to do?
Require countries to develop national strategies for sustainable development
What is an example of a national conservation scheme?
Countryside Stewardship Scheme
What did the Countryside Stewardship scheme include?
The government paid farmers and other land managers to conserve the English Landscape.
- This would sustain the diversity of the landscape and improve wildlife habitats
Why is phylogeny useful for classification?
Can be used to correct or confirm classification groups
What is discontinuous (discrete) variation?
Variation in which there are no in between values e.g. the sex of an organism
- Determined by a single gene (the ABO gene)
What is continuous variation?
What is it controlled by?
Values which have a range of possibilities
- Controlled by multiple genes (polygenes)
- also can be influenced by environmental factors
E.g. height of a plant
What is standard deviation used for?
To measure the spread of a set of data
What is a Student’s t-test used for?
To compare means of data values of two populations.
What is Spearman’s rank used for
Check for a correlation to see if there’s a relationship of the data
What is Simpson’s index used for?
To measure the biodiversity of an area, taking into account both species evenness and species richness
What is species richness?
The number of different species living in a habitat
What is species evenness?
A comparison of the numbers of individuals of each species living in a community.
What is an example of pesticide resistance?
- Sheep blowflies lay eggs in faecal matter around a sheep’s tail.
- The larvae can cause sores which can be fatal if untreated
- A pesticide “diazinon” was used to kill blowflies
- However some blowflies became resistance to this pesticide as they had evolved to have this advantage
What is sampling?
Sampling means taking measurements of a limited number of individuals organisms present in a particular area.
What is the advantage of sampling?
- Less expensive
- Less time needs to be spend to record data
- Able to find estimate the number of individuals or species in an area
What are the two types of sampling?
- Random
* Non-random
What is random sampling?
Selecting individuals by chance
How do you carry out a random sample?
- Mark out a grid using tape measures
- Randomly generate numbers for the x and y coordinate
- Take a sample at each of the coordinate pairs generated
What is non-random sampling?
The sample is not chosen at random
What are the 3 types of non-random sampling?
- Opportunistic sampling
- Stratified sampling
- Systematic sampling
What is opportunistic sampling?
- Uses organisms that are conveniently available
What is a disadvantage of opportunistic sampling? (2 examples)
May not be representative of the population
Bias
What is stratified sampling?
Populations divided into sub-groups which are proportional to its size
What is systemic sampling?
Selecting every nth term and collecting data from those specific numbers or areas.
