Module 4 Section 3 - Classification and Evolution Flashcards
Smithson
taxonomy
The science/study of classifying things into different categories
taxonomic hierarchy
Placing organisms in levels of organisation
species
One specific type of organism; the smallest group of organisms that share a common ancestor
phylogeny
The study of organisms’ evolutionary history
phylogenetic tree
A diagram showing the evolutionary relationships between different organisms
cladistics
Classifying organisms by considering phylogeny (their evolutionary history)
Which statement, A to D, best describes the relationship between classification and phylogeny?
A) classification and phylogeny are the same thing
B) modern classification reflects phylogeny
C) phylogeny is the science used in classification
D) phylogeny is naming the phyla used in classification
Not A and D - just definitions
Not C - that’s taxonomy
so the answer is B
morphology
The study of organisms’ structures (e.g. size, shape)
comparative morphology
Seeing how structures vary between different organisms, then using this to inform their classification and determine their evolutionary history
How do you write a binomial name?
In italics (or u͟n͟d͟e͟r͟l͟i͟n͟e͟d͟ if handwritten)
The genus is Capitalised whereas the species is not
Name the kingdoms you need to know. How many are there now though, and why?
- Plantae
- Animalia
- Fungi
- **Protoctista
- Prokaryotae**
There are now only four kingdoms, because prokaryotae was split into two domains.
Give six characteristics of the plantae kingdom.
- Eukaryotic
- Multicellular
- Contain chlorophyll
- Photosynthesise
- Have cellulose cell walls
- Autotrophic
Give four characteristics of the animalia kingdom.
- Eukaryotic
- Multicellular
- Heterotrophic
- No cell walls
Give three characteristics of the protoctista kingdom.
- Eukaryotic
- Unicellular or simple multicellular
- Usually live in water
Give four characteristics of the prokaryotae kingdom.
- Prokaryotic
- Unicellular
- No nucleus
- Smaller than 5 micrometers
Give four characteristics of the fungi kingdom.
- Eukaryotic
- Unicellular or multicellular
- Chitin cell wall
- Saprotrophic
Examples of fungi (3)
- mushrooms
- yeasts
- moulds
Examples of protoctista (2)
- algae
- protozoa (unicellular microscopic animals)
Examples of protoctista (2)
- algae
- protozoa (unicellular microscopic animals)
Initially, we used ____ ____ to classify organisms. Outline what this means.
comparative phylogeny i.e. using observable features like structure and behaviour
Give the three types of evidence taxonomists now use to classify organisms.
- Fossil record
- Molecular/biochemical evidence
- Embryological development
What is molecular evidence?
Analysing the similarities/differences in proteins and DNA sequences.
Give two examples of biochemical evidence for the reclassification of the kingdoms.
- Archaea have similar histones (DNA-bonded proteins) to Eukarya, whereas Bacteria do not
- RNA polymerase is different in Archaea and Bacteria
Give two examples of cellular evidence for the reclassification of the kingdoms.
- The bonds of the lipids in the Archaea and Bacteria cell membranes are different
- The flagella composition and development is different in Archaea and Bacteria
Name the domains.
- Eukarya
- Archaea
- Bacteria
The more similar two amino acid chains are, the ____.
more closely related they are likely to be
intraspecific variation
Variation within a species
interspecific variation
Variation between species
Different species have different ____, different organisms of the same species have different ____.
genes, alleles
Give four genetic causes of allele transfers to offspring.
- Independent assortment of homologous chromosomes and crossing over of chromatids in meiosis, creating new allele pairings
- Chance dictates which two gametes fertilise
- Mutations cause changes in the genetic code and so create new alleles
- Sexual reproduction mixes the parents’ alleles
Flagellum length is ____ data.
continuous
Antibiotic resistance is ____.
discontinuous
Leaf surface area is ____ data.
continuous
Blood group is ____ data.
discontinuous
Milk yield is ____ data.
continuous
Seed shape is ____ data.
discontinuous
Pigment production is ____ data.
discontinuous - e.g. some microogranims can make a type of pigment, some can’t
How can you graphically represent discontinuous variation?
Bar charts / pie charts
How can you graphically represent continuous variation?
Histograms
Is it continuous data or discontinuous data that changes gradually?
Continuous data - it can take a wide range of values
Discontinuous data falls into ____ ____.
discrete groups
Discontinuous data is generally caused by ____ variation.
genetic
Continuous data is generally caused by ____ variation.
a mix of genetic and environmental
Continuous variation is caused by ____ of genes.
groups
Discontinuous variation is caused by ____ of genes.
a couple (one or two)
Are flagella based on genetic factors, environmental factors or both?
Both - genetic factors determine whether a microogranism has the capability to produce one, but some microogranisms will only grow them under certain conditions (e.g. if metal ions are present).
Give two environmental causes of variation.
- Dog training (e.g. if a dog sits on command)
- Hydrangea flower colour
Is the size of contractile vacuole in amoebas genetic or environmental?
Environmental - a contractile vacuole is fluid-filled space that expands & contracts to collect & expel excess water, preventing the cell from swelling until it bursts
I think it’s a vacuole and not a vesicle as my notes say
What does the peak on a normal distribution represent?
The mean
What does a standard deviation of 1 mean?
Approximately 68% of data points fall within one standard deviation of the mean
What does a standard deviation of 2 mean?
Approximately 95% of data points fall within two standard deviations of the mean
What does a standard deviation of 3 mean?
Approximately 99.7% of data points fall within three standard deviations of the mean
standard deviation
The spread of values around the mean
Why is calculating the standard deviation more helpful than the range?
The range is more likely to be affected by anomalous results because it only takes into account two values
Statistical analysis determines the ____ of data.
significance
What does the D in Spearman’s rank coefficient formula represent?
The rank difference between the data pairs
What does the n in Spearman’s rank coefficient formula represent?
The number of data pairs
There are four plants with a height of 95cm. The first plant is meant to be ranked 7 in Spearman’s rank coefficient. What ranks do you assign the four plants?
Calculate the mean in the ranks: (7 + 8 + 9 + 10) / 4 = 8.5
You give all four plants a rank of 8.5
There are three months in a data set with an average rainfall of 30mm. The first month is meant to be ranked 10, but together they are each ranked 11. What is the next rank for the month with the next highest average rainfall?
11 * 3 = 33
33 - 10 - 11 - 12 = 0
i.e. the positions were 10, 11 and 12
Therefore the next rank will be 13.
What does a Spearman’s rank coefficient of
a) 0.89
b) -1
c) 0.2
d) 0.63
e) 0
mean?
a) Strong positive correlation
b) Perfect negative correlation (all points lie on the line of the best fit)
c) Weak positive correlation
d) Strong-ish positive corellation
e) No correlation
State four observations made by Darwin that led him to develop his theory of evolution.
- Offspring have some similar characteristics that are passed on from their parents
- Organisms produce more offspring than survive e.g. tadpoles
- Organisms of the same species have different characteristcs
- Individuals with the most beneficial characteristics for their environment are more likely to survive
selection pressure
An environmental factor that cuases a struggle/competition for survival e.g. food/water availability, temperature
The cytochrome C protein is found in almost all living organisms. Suggest what this means in terms of evolution.
Present in almost all living organisms = suggests we all evolved from a common ancestor
Describe how a phenotype becomes more prevalent within a population.
- Individuals show variation in their phenotypes due to mutations.
- There is a selection pressure from environmental factors [might need to state and explain these], creating a struggle for organisms to survive.
- Individuals with more helpful adaptations are more likely to survive and reproduce.
- These organisms pass on their beneficial allele to their offspring
- Over time, the proportion of the population with this beneficial allele increases.
- Over many generations, this leads to favourable alleles becoming more frequent within the population.
Note: environmental factors aren’t passed on - natural selection is solely about genetics
Give the three sources of evidence for evolution.
Palaeontology – studying the fossil record
Comparative anatomy – comparing the anatomy/features of different organisms
Comparative biochemistry – comparing the chemicals that make up organisms
Explain how the fossil fecord can be used as evidence for evolution.
Fossils can be arranged in chronological order showing how organisms gradually developed
Explain how DNA can be used as evidence for evolution.
Evolution suggests all living organisms evolved from a common ancestor. Organisms that have more similar DNA are more closely related (diverged more recently from a common ancestor) because fewer mutations to the DNA base sequence have occurred
The older the fossil, the ____ the organism.
simpler
How can fossils of different ages be used to compare organisms?
The anatomy of fossils shows the structure of the organism - similarities/differences between organisms can be observed
Give two disadvantages of using the fossil record.
- The fossil record is incomplete
- Fossils can be easily destroyed (e.g. volcanic/tectonic activity)
- It’s hard for organisms to become a fossil (the correct conditions are required, and many organisms decompose much too quickly)
homologous structure
A structure of an organism that is similar to the structure of other organisms, but may look slightly different or have different functions
Give an example of a homologous structure among animals.
Don’t need to know, just helps to remember homolgous structures better.
The arms & hands of humans, cats, whales and bats have similar bone skeletons, despite some being land animals, some aquatic life and some that can fly.
What two things does comparative anatomy encompass?
- Homologous structures
- Embryo development
How are embryos helpful in evidencing evolution?
Many animals’ embryos look very similar initially, suggesting they share a common ancestor and the animals develop in a similar way.
Give an example of how embryological development can be used as evidence for evolution.
Don’t need to know, just helps to remember the evidence for evolution better.
e.g. humans and fish both have gill slits in early development, but us humans lose ours before birth
-> we develop in a similar way and must share a common ancestor
What two things are often observed in comparative biochemistry as evidence for evolution?
Mostly proteins & nucleic acids
highly conserved
A sequence of bases that are the same (or very, very similar – as in only a few differences in bases) in different organisms
Give three examples of things that are highly conserved.
e.g. haemoglobin, cytochrome (protein involved in respiration) and rRNA (creates ribosomes)
Why are certain molecules highly conserved and others are not?
These chemicals (e.g. haemoglobin) are used in intrinsic processes - organisms can’t really survive without them (which is probably why they’re conserved - those that have mutations in these don’t survive due to natural selection).
Why do adaptations arise?
Mutations and natural selection
Organisms in one environment often have ____ adaptations. Explain your answer.
similar - the environmental conditions are the same, so the selective pressures are the same between organisms
What six things can well-adapted organisms do?
There’s four I keep forgetting
- find enough food and water to survive
- get enough nutrients
- survive diseases
- survive drastic environmental changes
- defend against predators
- have enough energy remaining to reproduce
Name the three types of adaptations.
- Anatomical (formerly structural)
- Physiological / biochemical (formerly structural)
- Behavioural
Give two examples of physiological adaptations.
- Thermoregulation
- Lowering metabolism in hibernation
analogous features
Features which appear similar but actually have different structures (often due to convergent evolution)
costs of antibiotic resistance
- Doctors have to spend more time finding an antibiotic that works, during which time the patient could become more sick/die
- Economic costs of developing new antibiotics, plus it is time-consuming to do so
Explain why comparing base sequences between organisms isn’t always reliable evidence for evolutionary trees.
mRNA base sequences may be different, but code for the same amino acids; codons are degenerate.
intraspecific variation
Variation between organisms of a species
interspecific variation examples
e.g. anatomical differences between species, behavioural differences (like migration/hunting in packs)
Explain how fossils can be used to provide evidence for the theory of evolution by natural selection. [2 marks]
Bit I often miss: use in evolution
Fossils can be dated, compared to other species (living or extinct) and fill in gaps in the evolutionary tree
