🔺🔥2.1 -Classification And Biodiversity Flashcards
Define the term phylogenetic
Reflecting evolutionary relatedness (grouping)
How do we know that 2 organisms are closely related
They have a more recent ancestor with each other than with organisms not in their group
What form of diagram is shown to highlight organism relatedness
Phylogenetic tree
Define the term phylogenetic tree
A diagram showing decent, with living organisms at the tips of the branches and ancestral species in the branches and trunk, with branch points representing common ancestors. The lengths of branches indicate the time between branch points
Which species exist in a phylogenetic tree?
The species at the top of the tree
Where are those extinct species located in a phylogenetic tree
They are not in the top row
LEARN STRUCTURE OF THE PHYLOGENETIC TREE
LEARN THE STRUCTURE OF THE PHYLOGENETIC TREE OF ALL ORGANISMS
Define taxonomy
The identification and naming of organisms
Define classification.
Putting items into groups
Define hierarchy
A system of ranking in which small groups are nested components of larger groups
Define taxon (pleural=taxa)
Nah group within a system of classification
What do bigger taxa contain
Smaller taxa with organisms more closely related than organisms outside the taxa
What is the hierarchal order of biological classification.
Domain> kingdom> phylum> class> order> family> genus> species
Give an example of a domain, kingdom and phylum
Domain = Eukaryota Kingdom = Animalia Phylum = Chordata
Give an example of class, order and family
Class = Mammalia Order = Primates Family = Hominidae
Give an example of the human genus and species
Genus = Homo Species = sapien
Note the capital letter on Homo and lower case s on sapien
What happens as you move down the hierarchy from domain to species?
Organisms in a taxon are more closely related
What happens as you move up the hierarchy from species to domain
Members of a taxon are less closely related
What does ‘a taxon is discrete mean’
At any level Of classification an organism belongs in one taxon and in no other
State 4 reasons why we need a classification system
- allows us to infer evolutionary relationships (same taxon :: assume closely related)
- if a new animals discover we can use characteristics (wings and beak) to determine taxon e.g birds
- easy to communicate
- conservationists find it more useful to count families than species
What are the 3 domains that every organism would belong under?
Eubacteria, Archaea and Eukaryota
Describe eubacteria
Familiar bacteria e.g E.coli and salmonella (prokaryotic)
Describe archaea
Bacteria which usually have an unusual metabolism e.g generate methane, live in marginal habitats (prokaryotic)
Define Eukaryota
Plantae, Animalia, Fungi and Protoctista
What are the 5 kingdoms
Prokaryota Protoctista Fungi Plantae Animalia
What does extremeophile mean?
Organism (archaea and eubacteria) who’s habitats are extreme (temp/pH/salt concentration)
Define phylum
A sub group of a kingdom with a distinct body plan e.g the phylum Chordata contains vertebrates
Define class
A sub group of a phylum e.g Mammalia for a class within the phylum Chordata
Define order
A sub group of a class
Define a family
A group within an order e.g flower families
Define a genus
A group of similar organisms e.g genus Panthera containing lions and tigers
Define species
A group of organisms sharing a large number of physical features and are able to interbreed to make fertile offspring
E.g members of panthera Leo can’t make fertile offspring with members of panthera Tigris :: are not the same species
Define prokaryota
Prokaryota are microscopic, the kingdom contains all the bacteria and cynobacteria (blue-green algae)
Define species that are Protoctista
- some are unicellular (major component of plankton)
- some are colonial
- some (spirogyra) have plant like cells
- some (amoeba) have animal like cells
- some (euglena) have characteristics plant and animal like
-some have many similar cells e.g seaweeds of algae
Name plants that are non flowering and describe how they reproduce
Mosses, horsetails and ferns reproduce with spores
Name flowering plants and describe how they reproduce
Conifers and flowering plants e.g rose reproduce with seeds
Name some examples of fungi
Yeasts (single celled)
Moulds such penicillium
Describe the structure of the fungi
Have hyphae that weave together to form the body of the fungus, a mycelium.
Some have cross-cell walls called septa which sub divide the hyphae
How many anamalia phylum are there?
Describe one word to describe most anamalia
- 35
- Motile (ability to move independently using metabolic energy)
Describe the nucleus in prokaryota, Protoctista, Eukaryota, Fungi and Animalia
prokaryota = none Protoctista = yes Plantae = yes Fungi = yes Animalia = yes
Describe the mitochondria in: prokaryota Protoctista Eukaryota Fungi Animalia
prokaryota = mesosome in some Protoctista = yes Plantae = yes Fungi = yes Animalia =yes
Describe the chloroplasts in: prokaryota Protoctista Eukaryota Fungi Animalia
prokaryota = photosynthetic lamellae in some Protoctista = some chloroplasts Plantae = yes Fungi = no Animalia = no
Describe the ribosomes in cytoplasm in: prokaryota Protoctista Eukaryota Fungi Animalia
prokaryota = 70s Protoctista = 80s Plantae = 80s Fungi = 80s Animalia = 80s
Describe the ER in: prokaryota Protoctista Eukaryota Fungi Animalia
prokaryota = none Protoctista = yes Plantae = yes Fungi = yes Animalia = yes
Describe the vacuole in: prokaryota Protoctista Eukaryota Fungi Animalia
prokaryota = none Protoctista = some Plantae = large, central and permanent Fungi = large centeral and permanent Animalia = small, scattered and temporary
Describe the cell wall in: prokaryota Protoctista Eukaryota Fungi Animalia
prokaryota = peptidoglycan/Murin Protoctista = some cellulose, some none Plantae = cellulose Fungi = chitin Animalia = none
Describe the nutrition in: prokaryota Protoctista Eukaryota Fungi Animalia
prokaryota = sapotrophic, autotrophic or parasitic Protoctista = autotrophic or heterotrophic Plantae = autotrophic Fungi = sapotrophic or parasitic Animalia = heterotrophic
Describe the nervous coordination in: prokaryota Protoctista Eukaryota Fungi Animalia
prokaryota = none Protoctista = none Plantae = none Fungi = none Animalia = yes
Define homologous structures
Structures in different species with a similar anatomical position and developmental origin, derived from a common ancestor
Define pentadactyl
Having 5 digits (in Chordates)
Define analogous structures
Babe a corresponding function and similar shape, but different developmental origin
E.g shark and dolphin
Define convergent evolution
Evolution where structures evolve similar properties but have different developmental origins
Define divergent evolution
Evolution where a common ancestral structure has evolved and performs different functions
E.g the pentadactyl limb is featured in birds, mammals, reptiles and amphibians but for different purposes e.g walking, swimming, flying and grasping
What are the 4 methods which we use to assess relatedness with genetic evidence
- DNA sequences
- DNA hybridisation
- Amino acid sequences
- Immunology
Describe how we use DNA sequencing to assess relatedness with genetic evidence
More closely related organisms show more similarity in DNA base sequences (which have mutated during evolution).
Describe how we use DNA hybridisation to assess relatedness with genetic evidence
1- extract DNA from 2 different species
2- separate DNA and cut into fragments
3- mix DNA from two species, where there is complimentary base pairing they hybridise together
4- this shows % DNA in common e.g chimpanzees and humans have approx 95% of shared DNA
Describe how we use Amino acid sequences to assess relatedness with genetic evidence
- sequence of amino acids in proteins is determined by DNA base sequence
- similarity in amino acid sequence of the same protein in 2 species shows relatedness
- e.g the fibrinogen molecule in mammals has allowed scientists to for a evolutionary tree
Describe how we use Immunology to assess relatedness with genetic evidence
- mix the antigens of one species (e.g blood protein albumin) with antibodies of another
- the antigens and antibodies make a precipitate
- the closer the evolutionary relationship, the more antigen and antibody react and make more precipitate
Define the reproductive definition of species
A group of organisms that can interbreed to produce fertile offspring
What is the morphological definition of species
If 2 organisms look very similar they are likely to be of the same species
What does the morphological definition of species take into account?
There may be ‘sexual dimorphism’ (e.g male lions having a man and female lions not) which needs to be taken into account
Why to organisms of different species not produced fertile offspring
Because they have different chromosome numbers or incompatible physiology so hybrids would not be viable
Name 2 animals that have reproduced to producer infertile offspring
Yak + Cow = Zho
What is taxonomy?
The identification and naming of organisms
What are 3 benefits of taxonomy?
- discover and describe biological diversity
- investigate evolutionary relationships between organisms
- classify organisms to reflect their evolutionary relationships
Define the term binomial system
The system of giving organisms a unique name with 2 parts, the genus and species
When was the binomial system introduced? By who?
1753
Linnaeus
What are the 3 main advantages of the binomial naming system
- unambiguous naming
- based on Latin, the scholarly language that is used worldwide
- implies 2 species are related by sharing part of their name r.g panthera Leo is related to panthera Tigris
Define biodiversity
The number of species and the number of individuals in each species In a specified region
How does biodiversity partly depend on the environment
- more plants grow at high light intensities, so bright environments support more herbivores and :: carnivores
- more energy flowing through and ecosystem produces more species. This means equatorial regions have a much higher biodiversity than polar regions
What are major areas of biodiversity referred as?
Biodiversity hotspots
What are the 3 main reasons why biodiversity can increase/decrease over time?
- Succession
- Natural selection
- Human influences
Describe how succession leads to varying biodiversity
Over time a community of organisms changed its habitat making it more suitable for other species this is called succession. This increased animal biodiversity but decreases plant biodiversity
NATURAL SELECTION IS DISCUSSED LATER IN THE COURSE
Learn about it later on pg 150
How has human influence impacted biodiversity
Humans have decrease biodiversity and caused extinction in some species
- oceans = over fishing + trawlers dredging the ocean floor disrupts habitats
- tropical rainforests = farming, roads and industry have destroyed habitats and driven many exclusive species to extinction
- global warming causes increased temperature resulting in the expansion of deserts
- rivers are polluted with industrial chemicals
What is one benefit of human activity and biodiversity
Can also support biodiversity through law implementation e.g sewers built in the themes turned the ‘great stink’ into a habitat for salmon, seahorses and a seals.
Name 3 points to highlight the significance of biodiversity
- small number of plant species provide staple diet for humans e.g what and rice
- medicinal drugs are derived from plants and fungi e.g for heart disease + antibiotics
- living organisms provide important raw materials (rubber and cotton etc)
What impact can a reduce in biodiversity have?
Why is this view criticised?
-as biodiversity decreases there’s less potential for new: foods, medicinal drugs and new raw materials
This is criticised as it is ‘human centred’ and we should protect biodiversity to preserve uniqueness of all organisms
Why are biodiversity index’s beneficial?
They are used to monitor biodiversity of a habitat over time to compare biodiversity in different habitats
What is the equation to calculate diversity (Sampson’s diversity index)
S= 1 - (sum of n( n-1)/ N(N-1)
N= total number of organisms present n= the number in each species
What can you tell from Simpson’s diversity index
The higher the numerical value the higher the biodiversity in an area
Why is having more different habitats in an area beneficial for biodiversity?
The more habitats the more ecological niches :: the more species can be accommodated and :: more biodiversity
Define polymorphism
The occurrence of more than one phenotype in a population that can’t be accounted for by mutation alone
What is a genes locus?
A genes position on a chromosome
When is polymorphism shown?
When a locus has two or more alleles at frequencies greater than what would occur by mutation alone, the more alleles the more polymorphic
Give an example of polymorphism in plants
-Gene T controls height, there are 2 different alleles
-In a poppy Gene S controls whether pollen can germinate in the stigma of a flower, there are 31 different alleles
:: Gene S has a greater biodiversity than gene T as more phenotypes (physical characteristic shown) for gene S than gene T
Give an example of polymorphism in humans
The ABO blood group
E.g in centeral American almost 100% have o (low biodiversity) whereas in New Guinea more have a and B (greater biodiversity)
How can % of recessive alleles inform about biodiversity
The lower the value of recessive alleles the higher the rate of biodiversity
Define genetic or DNA fingerprint/profile
Terms for a pattern unique for each individual, related to the base sequence of their DNA
What are SNPs (pronounces snips)
A DNA mutation where only one base mutates, resting a single base difference
SNPs stands for single nucleotide polymorphisms
What are HVRs?
- Regions of DNA that vary, 20-40 base sequences long,
- often repeated many times,
- uniques lengths of non-coding DNA are called hyper-variable regions
What is important to note about SNPs and HVRs
Not all DNA codes for protein, :: it is the non-coding regions that undergo mutation so individuals acquire different base sequences
How can we understand biodiversity from a DNA fingerprint?
The more SNPs and HVRs a population has, the more difference there are in its DNA fingerprint and :: indicate a greater biodiversity
Name one use for the identification of SNPs in genetic fingerprinting
Suggested link between SNPs and disease such as sickle cell anaemia, Alzheimer’s disease and cystic fibrosis
Define natural selection
The gradual process in which inherited characteristics become more or less common in a population, in response to the environment determining the breeding success of individuals possessing those characteristics
Describe the process of natural selection
1) mutations cause a difference in DNA
2) This causes differences in physical appearance or behaviour creating variation
3) some are more suited to the environment than others and out-compete then for resources creating a competitive advantage
4) those more suited survive better
5) those more suited to the environment have more offspring
6) offspring inherit advantageous alleles and so they are also suited to the environment
Give an example of natural selection creating biodiversity
A habitat becomes hotter :: over generations those more suited to warmth reproduce effectively until this passes onto most of population
Then a habitat becomes hotter and different features become advantageous and will be selected :: make up of population changes and natural selection creates biodiversity
How many natural selection decrease biodiversity
E.g when he dinosaurs were wiped out
-asteroid hits earth throwing dust reducing light intensity so plants can’t survive :: herbivores can’t :: carnivores can’t survive reducing biodiversity
Define adaptation
A change in a species creating a common useful characteristic.
The useful characteristic is called an ‘adaptive trait’
What 3 major types of adaptation are there?
Anatomical traits
Physiological traits
Behavioural traits
Describe an anatomical trait adaptation in animals and plants
Animal= sharks, dolphins and penguins all have streamlined bodies to be more efficient at escaping predators and catching food
Plant= some plants don’t have beelines (honey/nectar guides) and :: attract fewer pollinators e.g bees
Describe a physiological trait adaptation in mammals
During hibernation a polar bear resets its body thermostat to use less energy, the body temp drops to 26 degrees opposed to 37
Describe a physiological trait in plants
The leaves fall of djcidious plants when the temperature and light intensity drop in the autumn to reduce water loss by transpiration and the risk of dehydration in the winter
Describe a behavioural trait adaptation in animals
Mating rituals in animals e.g a peacock displaying its tail or dances by flamingos increase animals chance of reproducing
Describe a behavioural trait adaptation in plants
The hawthorn like many plants flowers In spring when it’s pollinating insects have emerged
Why is global warming harming animal and plant relationships
Because many plants are flowering before pollinating insects have emerged :: can’t be pollinated
What word should I use to describe species producing fertile offspring
INTERBREED
Give the name of a disease caused by the kingdoms below:
Protoctista
Prokaryota
Fungi
Protoctista = malaria Prokaryota = any bacterial disease e.g cholera Fungi= athletes foot
