Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology- Module 4 > 4.2.2 Classification and evolution > Flashcards

4.2.2 Classification and evolution Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Classification and Evolution - Topic 2.2

A

Classification and Evolution - Topic 2.2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why do we classify things?

A
  • to identify species
  • to predict characteristics
  • to find evolutionary links
  • by using a single classification worldwide, scientists can identify links between different organisms even if they live on different continents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are classficiation systems?
Phylogeny?
Taxonomoy?

A

It is the process by which living things are sorted into groups and the organisms within a group will share similar features.

Phylogeny: the study of how closely related species are, looking at evolutionary relationships

Taxonomy: the study of the principles behind classification (this uses similarites and differences and puts them into groups) - a taxonomist puts things into groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is lineal classification?

A

Contains 7 taxonomic groups:
Kingdom
Phylum
Class
Order
Family
Genus
Species

As you move down the hierarchy, there are more groups at each level, but fewer organisms in each group
The organisms in each group become more similar and share more of the same characteristics.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Definiton

More about Species

Lineal Classification

A

Species: a group of organisms that are able to reproduce to produce fertie offspring
- the smallest units of classification
- same physiology, morphology, and behaviour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do you lay it out?

Binomial Nomenclature
What is the advantage of it?

A

All species are given a name consisting of 2 parts (MUST ALL BE IN ITALICS/UNDERLINED)

1st word: organisms genus (MUST HAVE CAPITAL LETTER)
2nd word: organisms species (MUST HAVE ALL LOWERCASE)

e.g. Cat: Felis domesticus

Advantages:
- It is universal; an organism’s binomial name is the same everywhere in the world

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why are there now 5 kingdoms?

A
  • used to just be 2 kingdoms
  • as technology improved, so did scientific knowledge
  • this allowed plants to be seperated into more kingdoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 3 feeding systems?

A

All organisms feed in a specific way.
- Autotrophic
- Heterotrophic
- Sapotrophic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Feeding system 1

Autotrophic

A

An organism that transforms inorganic molecules into organic molecules (photosynthesis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Feeding system 2

Heterotrophic

A

An organism that has to eat and digest other organisms to gain organic molecules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Feeding system 3

Sapotrophic

A

Organisms that release extra-celullar enzymes and absorb nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the 5 kingdoms?

A
  • Prokaryotae
  • Protoctista
  • Fungi
  • Plantae
  • Animalia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the key features?

Prokaryotae

A
  • usually unicelullar
  • no membrane-bound organelles
  • no nucleus
  • have a loop of naked DNA that is not associated to any histone proteins
  • smaller ribosomes and smaller cells
  • carry out respiration on special membrane systems
  • cell wall made of peptidoglycan
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are they key features?

Protoctista

A
  • defined by exclusion (all do not fit into any of the other kingdoms)
  • eukaryotic
  • e.g. protozoa (animal-like cells)
  • e..g algae (plant-like cells)
  • feed autotrophically or heterotrophically
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are they key features?

Fungi

A
  • eukaryotic
  • cell wall made of chitin
  • unicellular or have mycelium which is made up of long threads (hyphae)
  • reproduced by means of spores
  • feed sapotrophically; some feed heterotrophically
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are they key features?

Plantae

A
  • eukaryotic
  • multicellular
  • cellls are differentiated to make tissues
  • cell wall made of cellulose
  • feed autotrophically
  • produce multicellular embryos from fertilised eggs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are they key features?

Animalia

A
  • eukaryotic
  • multicellular
  • cells are differentiated to make tissues
  • feed heterotrophicallly
  • usually able to move around
  • have fertilsed egs that develop into a ball of cells called a blastula
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What was early classification like?

A
  • based on observable characteristics (morphology and anatomy)
  • based on similarites in behaviour (live or move in water/air)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

4 of them

What advances have we had in technology?

A
  • light microscope
  • electron micrsocope
  • phyisology
  • biochemistry
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is used now to classify organisms?
How is it used?

A

DNA:
- the % of similar DNa shows how close the evolutionary relationship is
- the higher the % similarity, the more closely relaed i evolution the organisms are
- the lower the % similarity, the less closely related they are

Physiology and Morphology

Biochemistry:
- the more similar the protein amino acid sequence, the more closely relatd the organisms are in evolution and vice versa
- e.g. they look at Cytochrome C (protein used in respiration therefore in all living organsims). The amino acid sequenc is different in different organisms- the more similar, the more closely related the are.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What evidence led to a new classification system (domain)?

A

In 1990 Cart Woese suggested a new classification sytem based on:
-rRNA nucleotide sequences in eukaryotes & prokrayoes
-lipid structure and antibody sensitivity
Decided prokrayotes had 2 distinct groups based on molecular structure and metabolic pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the 3 Domains?
Give some more info on each

A

1) Eukaryotes: 80S ribosomes; RNa polymerase hs 12 proteins
2) Archae: 70S ribosomes; RNA polymerase has 8-10 proteins
3) Bacteria: 70S ribosomes; RNA polymerase has 5 proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is phylogeny?

A

The evolutionary history of a species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the relationship between classification and phylogeny?

A

Cladistics is a biological system of classification based on phylogeny.
As groups of orgnaims evolve from common ancestors, they keep the some of the same traits.
A cladogram shows how those traits diverge.
The closer the 2 organisms are in a cladogram, the more probable that they are closely related by evolution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is evolution?

A

A theory that describes the way that organisms evolve/change over many years, due to natural selection.

26
Q

What are the types of variation?

A

1) Discontuous variation
2) Continuous variation

1) Interspecific variation
2) Intraspecific variation

27
Q

What is discontinuous variation?
Give an example

A
  • individuals fall into a number of distinct classes/catergories
  • based on fatures thaat can be measured across a complete range
  • no in between values
  • controlled by one/few genes
  • environment has no effect on this type of variation
  • e.g. eye colour
28
Q

What is continuous variation?
Give an example

A
  • complete range of measuremtns from one extreme to the other
  • get a normal distribution curve due to the graduation from one extreme to the other: usually produces a bell-shaped curve= normal distribution
  • controlled by many genes (polygenic)
  • signifcantly affected by the environment
  • histogram
29
Q

(like INTER-house competitions)

What is interspecific variation?

A

Variation occurs between members of different species.

30
Q

What is intraspecific variation?

A

Variation occurs between members of the same species.

31
Q

What are the causes of variation?
Include examples

A

1) GENETIC: organism’s genetic material
e.g. eye colour; blood type
2) ENVIRONMENTAL: environment in which an organism lives in
e.g. education; tatoos

Both:
e.g. skin colour; height; weight

32
Q

What are genetic causes of variation?

A

1) Alleles: different forms of the same gene- individuals in a population inherit different alleles
2) Mutations: changes to the nucleotide/base sequence can cause changes to the teritary structure of a protein - 1. in somatic (body) cell= individiual affected 2. in gametes = can be passed onto offspring
3) Crossing over: Non-sister chromatids will form chiasmata during prophase 1 of meiosis- this allows shuffling of alleles between chromatids
4) Independent assortment: Homologus chromosomes line up randomly on the equator of the cell during metaphase 1- repeated when chromatids line up during metaphase 2.
5) Sexual reproduction: random fertilisation- many genetically different gametes produced during meiosis- individuals will contain a unique genetic code
6) Chance: organisms inherit different alleles from each parent

33
Q

What is standard deviation?
Equation?

A

It is a measure of how spread out the data is around the mean.
The greater the σ, the greater the spread of values = more diverse population
The lower the σ, the less spread of values = less variation

Equation:
∑= sum of
x̄= population mean
x= value measured
n= no. of samples

34
Q

What is T-test?
What is it used for?

A

A statistical test that can be used to compare the means of 2 populations
to see if there is a significant difference between 2 values
can be used to:
- compare the variation within a population
- compare the affects of biotic/abiotic factors

35
Q

How to calculate a T-test (t)?
Equation?

A
  • there must be enough data collected
  • data should be nrmlally distributed
  • a null hypothesis is needed: “There is no significant difference between the mean of … and the mean of …”

Equation:
x̄1 = mean of popualtion 1
x̄2 = mean of population 2
n = no. of individuals in the sample
s^2 = variance (standard deviation squared)

Critical value:
5% significane level
Degrees of freedom: (n1+ n2) -2

Conclusion: (ignore negatives)
If value of t> critical value, REJECT null hypothesis = there is a signifcant difference between pop1 and pop2
If value of t<critical value, ACCEPT null hypothesis = there is no signifcant difference = any difference is due to chance

36
Q

6 stages

What are the stages of natural selection?

A

1) Mutation: occurs naturally in gene; causes variants to occur (alleles)=variation
2) Variation: occurs between members of the same species due to random mutation
3) Selection pressure: if there is a change in the environment/mating/predators, then certain organisms with a selective advantage due to the mutated gene
4) Survive or die?: those with the mutated gene/allele survive and reproduce (advantageous charcteristics); those without that verison of the gene die
5) Pass it on: those that survive pass on the mutated gene/advantageous charactersitic to offspring
6) Generations: over many generations, the allele will increase in the population; this could potentially lead to the development of a new species

37
Q

Modern evolution examples

A
  • bacteria becoming resitant to antibiotics
  • bed bugs/headlice/sheep blowflies becoming resitant to insecticides
  • flavobacterium can now digest nylon/waste
  • rat resistance to wafanin
  • new virus strains emerging
  • plant tolerance to toxic metals
  • hedghogs that run away instead of roll up
  • rabbits resitant to myxomatosis
38
Q

What is an adaptation?

A

Adapatation: a feature of a living organism that increases its chances of survival and reprodcutive success.

39
Q

What is an anatomical adaptation?
What are the examples of them?

A

These are physical features that have adapted both internally or externally.
- Body covering: spines, fur, feathes: e.g. polar bears have thick hair to provide warmth
- Camouflage: the outer colour of an animal allows it to blend into its environment, making it harder for predators to spot it: e.g. snow hare changes colour to adapt to different surroundings
- Teeth: structure/ shape related to diet: e.g. herbivores like sheep have continously growing molars for chewing touhg grass
- Mimicry: copying other animals’ appearance or sounds allows a harmless organism to fool predators: e.g. hoverfly mimics makrings of a wasp to deter predators
- PLants: xerophytes- plants adapted to live in an environment with little water: e.g. marram grass

40
Q

What is a behavioural adaptation?
What are the examples of them?

A

These are responses to stimuli that increase the chances of survival.
- Survival: e.g. opossum plays dead; rabbit freezes when they think they’ve been seen
- Courtship: done to attract a mate; e.g. scorpions perform a dance to attract a mate
- Seasonal migration: animals move from one region to another when environmental conditions are more favourable
- Seasonal hibernation: period of inactivity in which animals body temp, heart rate, and breathing rate slow down to conserve energy, reducing animal’s need for food: e.g. brown bears hiberante during winter
- Innate behaviour: ability to do this is inherited through genes; allows organism to survive in habitat whihc it lives in: e.g. woodlice aboiding light; spiders build webs
- Learned behaviour: adatations are learnt from experence or fro observing another animal: e.g. the use of tools by sea otters

41
Q

What is a physiological adaptation?
What are the examples of them?

A

These are body proceses that help an organism to survive.
- Poison production: many reptiles produce venom to killl their prey and many plants produce poison in their leaves
- Water holding: allows organsims to survive in the desert for more than a year without access to water: e.g. cati and other desert plants can hold large amunts of water in their tissues

42
Q

What is convergent evolution?
What are analagous structures?

A

Organisms evolve similarities because they adapt to similar envornments r other selection pressures. They are unrelated but live in a similar way.

Features of different species that are similar in function (not necessarily in structure), but have a different genetic origin.

43
Q

Give an example of convergent evolution in plants

A

Aloe vera and Agave:
appear very similar as they have both adapted to survive the desert.
these species developed entirely seperately: Aloe in sub-saharan africa and Agave in mexio and southerun U.S

44
Q

Give 2 examples of convergent evolution in animals

A

Marsupial mole and Placental mole:
- marsupial =in australia = enter marsupium while still embryos
- placental = in rest of world = placnta connects embryo to mothers circulatory system in uterus
- BOTH: burrow through soft soil to find worms and grubs; streamlined body shape and modfied forelimbs for digging; velevty skin for smooth movemnt through soil
Flying phalangers and Fying squirells:
- both are gliders that eat insects an dplnts; skin is stretched betweeen forelimbs and hind limbs to provide a large S.A for gldiing from one tree to the next.

45
Q

How long ago would species that have seperatley in Australia and America have shared a common ancestor?
What areas do they show a resemblence?
What features show their distinct evolutionary relationship?
Why do species on different continents resemble each other?

A

Over 100 million years ago
Shape, locomotion type, feeding techniques
Different reproduction methods
They have adapted to fill similar niches

46
Q

What is natural selection?

A

The proccess by which organisms best suited to their environment survive and reproduce, passing on their alleles to their offspring.

47
Q

What did Darwin, Lyell, and Wallace do?
What was their joint proposal?

A

Darwin: proposed theor of natural selction
Lyell: suggested fossils were evidecneof aimals from million sof years ago and the principle of uniformitarianism (earth was hsaped by forces like erosion)
Wallace: sent his theories to Darwin for peer review- they were the same!

Joint proposal:
Darwin and Wllace’s theory of evolution was proposed in a joint presentation to the linnaean society
Darwin then released ‘The origin of Species’ which suggesetd man was descended from apes ( very controversial and against creationsism)

48
Q

What is variation?

A

The level of difference between individiuals.

49
Q

What evidence is their for the evolution theory?

A

1) Paleontology: sutdy of fossils and the fossil record
-shows evolutionary links -found in different aged rocks -shows similarites and differences in anatomy
2) Anatomy:
-comparative, so the more similar, the more closely related
3) Biochemsitry:
-looks at DNA, protein structure, and others -the more similar the structure, the more closely related they are

50
Q

What is a normal distribution curve?

A
  • has the same mean, median, and mode
  • bell shaped (symmetrial around the mean)
  • 50% of values> mean
  • 50% of values< mean
  • most values are close to the mean

On a graph:
- Within 1 standard deviation of the mean= 34% on either side of mean
- Within 2 stanard deviations of the mean= 34% +13.5% on each side of mean

51
Q

What must a well adapted organism be able to do?

A
52
Q

What are the 3 different types of adaptations?

A

1) Anatomical
2) Behavioural
3) Physiological

53
Q

What were Darwin’s new observations?

A

Competition between organisms to:
- avoid predation
- find food
- survive harsh environments
- raise young
- defend a teritory
- find a mate

That there is overproduction of offpsring:
-to ensure that some survive to pass on genes
all lviing things reproduce at a rate that is unsustainable

54
Q

What is selection presure?
What is survival of the fittest?

A

Factors tha affect an organisms chance of survival; for natural selection to occur, this will be a change in the envionment e.g. new preadtor, competition, food osurce, change in physical environment

  • Those that have the advantageous characteristic are most likely to survive and reproduce and pass on the advantageous characteristic/allele/gene
  • this is repeated over many generations
  • those that don’t have it, die
55
Q

Objections to the theory

A
  1. gaps in the fossil record
  2. surely natural selection would eliminate all exxagerated characteristics, but this can be explained by sexual selection
  3. went against creationism
  4. didn’t think the world was old enough
56
Q

Paleontology

How is a fossil produced?
What is the fossil record?
Why is the fossil record incomplete?

A
  • Formed when animla and plant remains are preserved in rocks (occurs over a very long period of time)
  • The different fossils within the diffrent strata ( layers/series of rock in the ground), fomring a sequence from oldest to youngest; shows that organisms have changed over time
  • Because many organisms aren’t fossilised as there soft-bodied and decompose quickly. Many fossils have been destroyed and conditions needed for fossils to form aren’t always present.
57
Q

What is spearmean’s rank?
How do you calculate it?

A
  • It is used to find the correlation between 2 sets of data:
    +1 = perfect positive correlation
    0 = no correlation
    -1 = perfect negative correlation
  • It can be used even if the varaibles don’t have a linear relationship, and they dont have to be normal distribution

Equation:
∑ = sum of
D = difference in ranks
n = no. of pairs of data

  1. Always need a null hypothesis as a starting point => “there is no statistically significant corrleation between … and … “
  2. Rank data set 1 from lowest to highest
  3. Rank data set 2
  4. Do difference in rank ans square value
  5. Use equation
  6. Find critical value (no. of pairs and 5%)
  7. Above null hypothesis= REJECT
58
Q

Paleontology

What is the proof that life forms have evolved over an extremely long period of time?
How can fossils prove there are ecological links between species?
How can scientists show how closely related organism have evolved from the same ancestor?

A
  • fossils of simplest organisms e.g. bacteria and simple algae are found in the oldest rocks whilst fossils of more complex organisms are found in more recent rocks
  • the sequence in which organisms are found matches their ecologcial links to each other, e.g. plants appaear before animal fossils
  • by studying similarities in the anatomy of the fossil organisms.
59
Q

Comparative anatomy

What is comparative anatomy?
What is a homologous structure?
What is an example?

A
  • the study of similarites and differences in the anatomy of different living species
  • a structure that appaears superficcialy different in different organisms but has the same underlying structure
  • Limsbs in vertebrates are diffferent as they’re sued for a variety of different functions such as running, jumping, and flying- the common underlinying bone struture is due to being evolved from a common ancestor
60
Q

Comparative anatomy

What is divergent evolution?
Why might it occur?
How are homologouus features evidence of it?
Example?

A
  • decribes how, from a common ancestor, different species have volved, each with a different set of adaptive features
  • when closely related species diversifyto adapt to new habitats as a result of migration or loss of habitat
  • because different species have the same underlying structure, therfore they must have evolve from a common ancestor
  • darwin’s finches evolved different beak shapes in response to varying food sources
61
Q

Comparative biochemistry

What is comparative biochemistry?
What molecules are in most species?
What is neutral evolution in terms of biochemistry?

A
  • the study of similarites and differences in the proteins and other molecules that control life processes
  • cytochrome C (protein involved in respiration and rRna (ribosomal RNA)
  • most of the variability in the structure of a molecule does not affect its function. the variability is outisde of the molecule’s functional regions. since they have no effect on function, their accumulation is not affcted by natural selection.
62
Q

Comparative biochemistry

How do scientists discover how closely related 2 species are?
Why is ribosomal RNA often used to determine the relationship between species?

A
  • molecular sequence of a particular molecule is compared
  • look at order of DNA based/ orderof amino acids in a protein: the no. of differences that exist are plotted against the rte the molecule undergoes netural base pair substitution
  • then estimate the point at which 2 species last shared a common ancestor
  • species that are more closely related have the more similar DNA and proteins
  • it has a very slow rate of substitution so it is commonly used together with fossil information to determine relationships between ancient species.

Biology- Module 4 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions