10 - Classification and evolution Flashcards
1
Q
classification systems - taxonomic
A
Kingdom
phylum
class
order
family
genus
species
2
Q
why do scientist classify organisms
A
- to identify species
- to predict characteristics
- to find evolutionary links
3
Q
how are organisms classified?
A
- begins by separating organism into the three domains archaea, bacteria and eukarya
- s move down the groups there are fewer organisms in each, they become more similar and share more characteristics
4
Q
species
A
- contains only one type of organisms
- a group or organisms that are able to reproduce to produce fertile offspring
5
Q
how to name organism
A
binomial nomenclature
Genus species
6
Q
the five kingdoms
A
- prokaryotae (bacteria)
- Protoctista (unicellular eukaryotes)
- Fungi (yeast, mould and mushrooms)
- Plantae (the plants)
- Animalie (the animals)
7
Q
Prokaryotae
A
- prokaryotes
- unicellular
- no nucleus or other membrane bound organelles
- small ribosomes - naked DNA
- no visible feeding mechanism - nutrients absorbed through the cell wall or produced by PHS
- Staphylococcus aureus
8
Q
Protoctista
A
- mainly unicellular
- eukaryotes
- a nucleus and membrane bound organelles
- some chloroplasts
- some are sessile, other move by cillia, flagella or by amoeboid mechanisms
- nutrients acquired by PHS of by ingestion of other organisms
- Amoeba and paramecium
9
Q
Fungi
A
- eukaryotes
- uni or multicellular
- a nucleus and membrane bound organelles and a cell wall made of chitin
- no chloroplast or chlorophyll
- no mechanism for locomotion
- most have a body or mycelium made of threads of hyphae
- nutrients acquired by absorption - mainly form decaying material (saprophytic)
- store food as glycogen
- mushrooms, mould and yeast
10
Q
plantae
A
- eukaryotes
- multicellular
- a nucleus and membrane bound organelles like chloroplasts and a cell wall made of cellulose
- contains chlorophyll
- most don’t move but gametes can by cillia or flagella
- nutrients from PHS
-store food as starch
11
Q
Animalia
A
- eukaryotes
- multicellular
- nucleus and membrane bound organelles
- no cell wall
- no chloroplast
- move with cillia, flagella or contractile proteins
- nutrients form ingestion
- store food as glycogen
12
Q
what is the Three Domain System
A
- organisms are classified into 3 domains and 6 kingdoms based on differences in nucleotides in rRNA, membrane lipid structures and sensitivity to antibiotics
- Eukarya, Archaea and bacteria
Domain -> kingdom
Bacteria - > eubacteria
Archaea -> archaebacteria
Eukarya -> protoctista, plantae, fungi and animalia
13
Q
Eukarya
A
- 80s ribosomes
- RNA polymerase contains 12 proteins
14
Q
archaea
A
- 70s ribosomes
- RNA polymerase have between 8 to 10 proteins and are similar to eukaryotic ribosome
15
Q
Bacteria
A
- 70s ribosomes
- RNA polymerase contains 5 proteins
16
Q
archaebacteria
A
- can live in extreme environments
- like hot thermal vent, anaerobic conditions and highly acidic conditions
17
Q
Eubacteria
A
‘true bacteria’
18
Q
phylogeny
A
- evolutionary relationships
- shows how related organisms are
19
Q
evidence for evolution
A
- palaeontology - study of fossils
- comparative anatomy - study of similarities and differences between anatomy
- comparative biochemistry- similarities and differences between the chemical makeup of organism
20
Q
Fossils
A
formed when animal and plant remains are preserved in rocks
- over time sediment on the earths surfaces forms layers (strata) of rock
- different layers correspond to different geological era, so can show how organisms change over time
21
Q
evidence provided by the fossil record
A
- fossils of the simplest organisms like bacteria are found in the oldest rocks. More complex ones are found in recent rocks, SO simple life forms gradually evolved over a long time into something more complex
- sequence in how organisms are found matches their ecological links to each other
- similarities in anatomy of fossils show how closely related organisms have evolved from the same ancestor
22
Q
comparative anatomy
A
the study of similarities and differences in the anatomy of different living species
23
Q
Homologous structures
A
- a structure that appears superficially different in different organism, it has the same underlying structure
- they have evolved from a common ancestor and the structure has evolved from the same structures
- it is evidence for divergent evolution
-> how from a common ancestor, different species have evolved with a different set of features (adapting to different environment)
24
Q
comparative biochemistry
A
- the study of similarities and differences between the proteins and other molecules that control life processes
- they are highly conserved
-main ones are cytochrome c and rRNA - can discover how closely two species are related by comparing the order of DNA bases in a gene for a protein
- the number of differences are plotted against the rate the molecules undergoes neutral substitutions
-more similar the more related
25
variation
differences in the characteristics between organisms
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interspecific variation
variation between members of different species
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intraspecific variation
variation between members of the same species
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factors of variation
- genetic variation - differences in genetic material
- environmental variation
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causes of genetic variation
- Alleles
- Mutations
- Meiosis
- sexual reproduction
- chance
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Alleles - causes of genetic variation
- genes have different alleles (alternative forms)
- different alleles form different effects
- depending on the parental combination, different characteristic of the offspring happen
- individuals in a species population may inherit different alleles of a gene
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Mutations - causes of genetic variation
- changes in DNA sequences changes the proteins coded for
- this can change the physical and metabolic characteristic
- if a mutation is in a somatic cell it only affects the individual
- if it is in the gamete it is passed to offspring
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Meiosis - causes of genetic variation
genetic material inherited from the parents is mixed up by independent assortment and crossing over
- leading to the gametes showing variation
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sexual reproduction - causes of genetic variation
- offspring inherit genes from two parents, each individual produced differs from the parents
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Chance - causes of genetic variation
- many different produced from the parents genome
- it is a result of chance as to which two gametes combine
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discontinuous variation
- characteristic can only result in a certain value
- no in between values
- variation determined purely by genetic factors is discontinuous
- use a bar chart or pie chart
36
continuous variation
- can take any value within a range
- height and mass
- characteristic are controlled by many genes and influenced by the environment
- frequency table and histogram
37
normal distribution curve
- when continuous variation data is plotted it is bell shaped
- mean=median=mode
- bell shaped, symmetrical about the mean
- 50% of the values are less than and more than the mean
- most values lie close to the mean
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standard deviation
measures how spread out the data is
39
students t-test
compare the means of data values of two populations
40
spearman's rank correlation coefficient
used to consider relationships between two sets of data
- no correlation = 0
- positive = +1
- negative =-1
41
adaptations
are characteristic that increase a organisms chance of survival and reproduction in its environment
- anatomical - physical
- behavioural - how they act
- physiological - processes in the organisms
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anatomical adaptations
- body coverings
- camouflage
- teeth
- mimicry
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Behavioural adaptations
- survival behaviours
- courtship
- seasonal behaviours- migration, hibernation
can fall in to two categories
- innate - inherited through genes
- learned - adaptations learnt from observing other animals
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physiological adaptations
- poison production
- antibiotics
- water holding
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analogous structures
structures that have adapted to perform the same function but have different genetic origin
46
what does analogous structures provide evidence for
convergent evolutions
-> when unrelated species begin to share similar traits
-organisms have adapted to similar environments or selection pressures
47
selection pressure
factors that affect the organisms chances of survival or reproductive success
48
natural selection overview
- organism that are best adapted to the environment are more likely to survives and reproduce then those who are poorly adapted
- these adaptations become more common as the characteristics are passed on to the next generation
49
natural selection steps
- organisms in a species show variation in their characteristics caused by differences in their genes
- organisms whose characteristic is best adapted to a selection pressure like competition have an increased chance of surviving and successfully reproduced. well less adapted ones die or fails to reproduce
- successful organisms pass the allele encoding the advantageous characteristic onto their offspring. organisms that possess the non-advantageous allele are less likely to successfully pass it on
- this process is repeated over generation. Over time the proportion of individuals with the advantageous adaptation increases. So the frequency of the allele increases in the populations gene pool
- over a long time this process can lead to the evolution of a new species
50
modern examples of evolution
- antibiotic resistant bacteria
- peppered moths
- sheep blowflies
flavobacterium
51
antibiotic resistant bacteria - modern examples of evolution
- bacteria reproduce very fast and can evolve in a sort time. when they replicate, DNA can be altered and some mutations can provide resistances the biotics
- when exposed to the antibiotics, they survives and reproduces, passing on the advantageous allele - eventually becoming the main characteristic.
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