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biology year 1 > topic 3 : classification > Flashcards

topic 3 : classification Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

list the classification hierarchy

A

domain, kingdom, phylum, class, order, family, genus, species

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2
Q

what is classification

A

process of naming and organising organisms into groups based on their characteristics

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3
Q

what is taxonomy

A

the science of describing, classifying and naming living organisms

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4
Q

why is a classification system needed in biology

A

The classification system provides great deal of information about the characteristics of organisms.

Using scientific names can therefore act as a shorthand method for describing a plant or animal.

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5
Q

what are the 3 main taxonomic groups (domains)

A
  • archaea
  • bacteria
  • eukarya
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6
Q

describe archaea

A
  • contain 1 kingdom
  • archaebacteria
  • they are extremophiles
  • separated from bacteria because difference in dna and structure
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7
Q

describe bacteria

A
  • contain 1 kingdom
  • eubacteria (unicellular, no membrane-bound organelles
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8
Q

describe eukarya

A
  • contain 4 kingdoms
  • protoctista (auto/heterotrophic, single/multicellular, microscoping, some plant-like and some animal like)
  • fungi (heterotrophic, cannot photosynthesise, mostly saprophytic (extracellular digestion), chitin cell wall, reproduce by using spores)
    *plantae (autrotrophic, carry out photosynthesis using chlorophyll, cellulose cell wall
  • Animalia (heterotrophic, capable of whole body movement, no cell wall)
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9
Q

what is the binomial nomenclature name ‘template’

A

Genus species (eg Homo sapiens)

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10
Q

what are the 6 species models

A
  • morphological
  • reproductive
  • ecological
  • mate-recognition
  • genetics
  • evolutionary
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11
Q

what is the morphological species concept

A

organisation of species based on their appearance

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12
Q

what is the issue with the morphological species concept

A

some organisms show sexual dimorphism (great difference in appearance between males and females).

  • also, many organisms may look different in different stages of their lifecycle
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13
Q

what is the reproductive species concept

A

group of organisms with similar characteristics that interbreed to produce fertile offspring

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14
Q

what is the issue with the reproductive species concept

A

many plant species can interbreed with each other.

  • also, it doesnt work for organisms that can reproduce asexuallym or for fossil species
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15
Q

what is the ecological species model

what is the problem with this model

A

based on ecological niche

many species can occupy more than 1 niche

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16
Q

what is the mate-recognition species model

what is the problem with this model

A

based on unique fertilisation system or mating behaviour

many species mate with each other

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17
Q

what is the genetic species model

what is the problem with this model

A

based on DNA evidence

the amt o genetic diff for species to be classified as differents needs to be calculated/decided

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18
Q

what is the evolutionary species model

what is the problem with this model

A

based on shared evolutionary relationships

not a clear evolutionary pathway for every organism

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19
Q

what is the definition of species

A

A group of organisms with similar morphological and physiological features that able to breed together and produce fertile offspring.

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20
Q

why does no definition work for species

A

here are limitations to this model: cross breeding can occur (rare but still possible), some individuals of a species don’t interbreed because they’re geographically separated from each other, and there are other ways to categorise species like through genetic analysis, evolutionary analysis, mate recognition.
- some organisms reproduce asexually

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21
Q

Why can it be difficult to assign organisms to one species?

A

it is difficult to assign an individual to a species/ identify new ones because over time organisms are always evolving - you would have to say that species are changing morphologically and genetically over time. And then it can be subjective and hard to determine how similar 2 individuals have to be to class them as the same species

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22
Q

what is molecular phylogeny

A

analysis of the genetic material of organisms to establish their evolutionary relationships

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23
Q

why is phylogeny better than other species models

A
  • shows the evolutionary relationship between organisms
  • shows evolution timeline (the further up the tree you go, the more recent the species)
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24
Q

what are some ways to carry out molecular phylogeny (3 ways)

A
  • dna sequencing : finding the base pairs all or part of the genome of an organism
  • leads to DNA profiling (patterns are identified by looking at the non-coding areas of DNA) : can identidy relationships between organisms or species as patterns of the DNA are similar
  • Bioinformatics : development of software and tools to organise/analyse biological data
  • DNA barcodes : produce global standard for species identification by using a short section of DNA and comparing to other organisms (like DNA profiling, the more similar the DNA, the more like the species)
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25
Q

why is gel electrophorisis used

A

identifying species/evolutionary links through patterns of DNA/RNA and proteins

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26
Q

describe the process of gel electrophorisis

A
  1. samples added to wells on agarose gel plate along with known samples to compare
  2. samples treated with restriction enzymes that cut DNA into fragments
  3. gel contains dye - binds to the fragments and fluoresces under UV light
  4. electric current passed through gel, fragments of DNA move at diff rate (shorter ones are faster) from -ve cathode to +ve anode (DNA is negatively charged, so they will move to the positive side)
  5. switched off when the dye reaches the end of the plate (it moves faster than DNA)
  6. UV light shone to show patterns

then you can compare the two samples together or compare it to your original set of dna

27
Q

what is the role of scientific journals, the peer review process and scientific conferences in validating new evidence supporting the accepted theory of evolution

A
  • scientific journals : dedicated to research that other scientists can read
  • peer review ; reliability assessed by other scientists in the field (are the data and scientific methods reliable? is the paper significant? can the results be reproduces? is the paper original?)
  • scientific conferences : scientists in the same field can discuss ideas and theories. Validity can be challenged, promoting new techniques
28
Q

what is the evidence for three-domain model

A
  • scientists had accepted that life was categorised into prokaryotic and eukaryotic
  • but in 1970, woese collected evidence (RNA sequences) for a new group, Archaea (evidence presented in scientific journal)
  • scientists then studied the methods and results in peer review
  • repetition and extensions of woese’s work resulted in recognition of Archaea (known that 3 groups have unique RNA seq)
29
Q

what is the definition of natural selection

A

process by which best adapted organisms in an environment are most likely to survive and reproduce, passing on advantageous alleles to offspring

30
Q

what is evolution

A

process by which natural selection acts on variation to bring about adaptations and eventually speciation

or

process by which allele frequency in a gene pool changes over time

31
Q

what is the theory of evolution by natural selection

A
  • due to mutations, a variety of alleles are in population, causing genetic and phenotypic diversity
  • an environmental change occurs and the selection pressure changes
  • individuals have advantageous alleles that give selective advantage - they survive and reproduce, passing on favourable alleles
  • over many generations, the frequency of alleles in a pop changes
32
Q

what is a niche

A

the role an organism plays in the habitat it lives in

33
Q

what happens if there are species with the same niche

A

they compete with each other and the best adapted species will survive

34
Q

what are anatomical adaptations

A

involve the form and structure of organism
(eg thich blubber in seals, sharp claws)

35
Q

what is a physiological adaptation

A

involve the way the body of organism works, the biochemical pathways/ensymes (eg. mammalian diving reflex (bp lowers when entering water))

36
Q

what is behavioural adaptations

A

changes to programmed/instinctive behaviour (migration, mating rituals)

37
Q

what us the evolutionary race between pathogens and medicine

A
  • bacteria reproduce very quickly
  • they can show variation/mutation (meaning that they could be resistant to antibiotics)
  • when antibiotics used, it applies a selection pressure against the bacteria without the advantageous gene (they will die out)
  • bacteria with resistance survive and reproduce to increase numbers (passing on the favourable alleles)
  • over many generations, the frequency of the favourable allele rises
38
Q

factors that increase antibiotic resistance

A
  • overuse of prescription
  • not completing antibioitc course
  • poor hygiene in hosptials
  • use in food products
  • overuse for viral infections
39
Q

how can antibiotic resistance be overcome

A
  • reduce the use of wide-spectrum antibiotics
  • reduce use in farm animals
  • prescribic specific antibiotics for infections
  • DNA seq to target resistant bacteria
  • development of new bacteria
  • education to patient (complete course)
40
Q

what is speciation

A

formation of new species as a result of reproductive isolation (cannot interbreed)

41
Q

what is genetic drift

A

fluctuations in allele frequences - can cause a population become a new species from the original population

42
Q

what is gene pool

A

the alleles of all the genes in a population

43
Q

what is allopatric speciation

A
  • result of physical or geographucal isolation (no interbreeding)
44
Q

what is an endemic species

A

evolve in geographical isolation and can only be found in one place

45
Q

what is sympatric speciation

A
  • occurs within a population living in the same area (reproductively isolated due to mechanical behaviour (birds being attracted to different songs) or seasonal (flowering of plants in diff times)…

or….

result of mutation, where mutated individuals reproduce exclusively from the rest

46
Q

what is the definition biodiversity

A

measure of variety of life in an area

47
Q

how can biodiversity be measured

A
  • number of different ecosystems
  • number of species
  • number of individual within each species
  • genetic diversity
48
Q

what is genetic diversity

A

genetic differences between individuals in a species - number of alleles in a gene pool

49
Q

what is species richness

A

number of species in the area

50
Q

what is species abundance

A

number of individuals in a species

51
Q

what is relative species abundance

A

relative numbers of species in the area

52
Q

why do endemic species have low biodiversity

A

small gene pool (vulnerable to changes), adapted to 1 environment.

53
Q

what is the allele frequency

A

frequency at which the allele appears in a population

54
Q

what are the ethical reasons for maintenance of biodiversity

A
  • denying future generations the natural resources
  • nature is a source of pleasure (cultural services)
  • unique combinations of DNA are lost
  • humans don’t have the right to cause exinction of species that we share the planet with
55
Q

what are the economic reasons for maintenance of biodiversity

A
  • purification of air and water
  • provisions (food, fibres, fuel and water)
  • stabalising atmosphere and climate
  • soil formation and nutrient recycling for crops to grow
56
Q

why is conservation needed

A

needed for sustaibable development : supplying people with what they need (eg. food, energy, housing) with minimal effects on habitats and wildlife

57
Q

what is insitu conservation

A
  • conservation of ecosystem and natural habitat where there is a maintenance and recovery of viable populations of species in their natural surroundings.
  • this is done by national parks, wildlife reserves
  • these areas are monitored and protected from unwanted human activity are
58
Q

what are the adv and disadv of insitu

A

+ve
- not removing species from natural ecosystem
- ecological integrity - not as disruptive
- helps larger populations
- cheaper than ex situ
-organisms can adapt and evolve naturally

-ve
- require large area
- risk of disease/natural disaster
- doesnt ensure survival of species
- ecotourism can damage reserves

59
Q

what is ex situ conservatin

A

conservaiton of living organisms outside of their natural habitat

60
Q

how can seed banks be conserved

A

seeds from endangered olants can be stored n=in a dormant state
- stored in cool, dry onditions, seends are periodially tested for viability
- seeds take up less space and produce many so samples take easily

  • propagation in plants
61
Q

how can animals be conserved (ex situ)

A
  • zoos and wildlife parks often have inbreeding as there are few individuals
  • to combat this, they don’t allow organisms to breed with the same partner repeatedly
  • use IVF
62
Q

how can seed banks be conserved

A

seeds from endangered plants can be stored n=in a dormant state
- stored in cool, dry conditions, seeds are periodically tested for viability
- seeds take up less space and produce many so samples take easily

  • propagation in plants
63
Q

what are the adv and disadv of ex situ

A

+ve
- protected from poachers
- reproductive techniques maximised
- health monitored
- reintroduce organisms to natural habitat again

-ve
- limited genetic diveristy (inbreeding)
- hard to provide suitable environment
- hard to adjust back to life in wild
- expensive
- harm to seeds by pests

biology year 1 (4 decks)

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