Chapter 10 - Classification and Evolution Flashcards
What are taxonomic groups?
The groups of classification ordered in a hierarchical structure
What are the 7 taxonomic groups in order (not including domain)?
Kingdom Phylum Class Order Family Genus Species
Why do scientists classify organisms?
- To help identify species
- To predict characteristics
- To find evolutionary links
What are the 3 domains?
Archaea, Bacteria and Eukarya
What is the smallest units of classification?
Species
What is the plural of genus?
Genera
What species do infertile offspring belong to?
They do not belong to any offspring- organisms like mules, who are infertile, are not classified to any species
What is a species?
A group of organisms that are able to reproduce to produce fertile offspring
What is the system of naming organisms known as?
Binomial nomenclature
In binomial nomenclature, what does the first word indicate?
The organisms’ genus
In binomial nomenclature, what does the second word indicate?
The organisms’ species
What are the 5 kingdoms?
Prokaryotae (bacteria) Protoctista Fungi Plantae (plants) Animalia (animals)
What are the general features of prokaryotes?
- Unicellular
- No nucleus or other membrane-bound organelles
- No visible feeding mechanisms (nutrients are absorbed or produced internally via photosynthesis)
What are the general features of protoctista?
- (Mostly) unicellular
- Nucleus and other membrane-bound organelles present
- Some have chloroplasts
- Can be autotrophic, heterotrophic or both
What are the general features of fungi?
- Unicellular or multicellular
- Nucleus and other membrane-bound organelles present
- Cell wall composed mostly of chitin
- No chloroplasts or mechanisms for locomotion
- Saprophytic feeders
- Most store food as glycogen
What are the general features of plants?
- Multicellular
- Nucleus and other membrane-bound organelles present (including chloroplasts)
- Autotrophic feeders
- Store food as starch
What are the general features of animals?
- Multicellular
- Nucleus and other membrane-bound organelles present
- No cell walls
- Heterotrophic feeders
- Store food as glycogen
What ribosomes do eukarya have?
80s ribosomes
How many proteins does eukarya DNA polymerase contain?
12
What ribosomes do archaea have?
70s ribosomes
How many proteins does archeae DNA polymerase contain?
Between 8-10
What ribosomes do bacteria have?
70s ribosomes
How many proteins does bacteria DNA polymerase contain?
5
What kingdom does the archeae domain lead on to?
Archaebacteria
What kingdom does the bacteria domain lead on to?
Eubacteria
What kingdoms does the eukarya domain lead on to?
Plantae, Fungi and Animalia
Where do archeaebacteria primarily exist?
In extreme environments, such as hot thermal vents or highly acidic areas
What is the difference between the six-kingdom system and the traditional five-kingdom system?
In the six-kingdom system, prokaryotae are split up into eubacteria and archaebacteria
What are saphrophytic feeders?
Organisms that aquire nutrients through absorbtion from decayed organic material
What is phylogeny?
Evolutionary relationships between organisms
What is a phylogenetic tree?
A branched diagram, which shows the evolutionary relationships between organisms, including common ancestors`
What is the main difference between historical classification systems and phylogeny?
Historical classification systems are based on physical characteristics, whereas phylogeny is based on evolutionary relationships
What are the advantages of phylogeny?
- Provides a continuous tree, meaning you can be more specific than with grouping
- Can see common ancestors
- It is not hierarchical
What is the Linnaean system?
Taxonomy
What is palaeontology?
The study of fossils and fossil record
What is comparative anatomy?
The study of similarities and differences between organisms anatomy
What is comparative biochemistry?
The study of similarities and differences between the chemical makeup of organisms
How can palaeontology be used to provide evolutionary evidence?
- Fossils of the simplest organisms are found in the oldest rocks, and more complex organisms in newer rocks; this supports the idea that life has developed over long periods of time, becoming more complex
- Fossils allow relationships between extinct and living organisms to be investigated
Why is fossil record incomplete?
Some organisms do not fossilise, and many others have been destroyed naturally over time
What are homologous structures?
Features of organisms that may look different and perform different functions, however have the same underlying structure (e.g. bat wings and human arms)
What is divergent evolution?
The idea that from a common ancestor, different species have evolved, each with a different set of adaptive features
How does comparative biochemistry work?
DNA and protein sequences are studied in various organisms, and the amount of difference between them can be used to see how closely the two organisms are related
What is interspecific variation?
Differences between different species
What is intraspecific variation?
Differences between organisms within a species
What are the two factors that cause variation?
Genetic variation
Environmental variation
3 genetic causes of variation
- Mutations
- Meiosis/sexual reproduction
- Allele variants
What is discontinuous/discrete variation?
Variation that can result only in certain outcomes (for example male or female, blood type etc)
What is continuous variation?
Variation that can result in a continuum of results in a range (for example height, mass etc)
What are the characteristics of normal distribution?
- Mean, mode and median are the same
- Bell-shaped and symmetrical
- Most values are close to the mean, with few at the extremes
What is standard deviation a measure of?
How spread out data is
What is the relationship between the spread of data and standard deviation?
The greater the spread of data, the larger the standard deviation
How many results are within 1 standard deviation of the mean?
68%
How many results are within 2 standard deviations of the mean?
95%
How many results are within 3 standard deviations of the mean?
99.7%
What are the 3 things you need to know to calculate standard deviation?
x= the value being measured _x= the mean value n= the total number of values in the sample
What is the first step to calculate standard deviation (after finding the mean)?
Subtract the mean from each measured value and square this number.
Then find the sum of these values
E.G.
If the mean is 5, and the values in the sample are 3, 2 and 8, you have to do (3-5)^2+(2-5)^2+(8-5)^2
What is the second step to calculate standard deviation?
Divide the sum of the (value-mean)^2 …. by the total number of values - 1
If the values in the sample were 3, 2 and 8, the total number of values would be 3. You then subtract 1 from this number to give what you have to divide by…
E.G.
So it would be (3-5)^2+(2-5)^2+(8-5)^2 / 2
What is the final step to calculate standard deviation?
Square root the final value you got from the last step
What is a null hypothesis?
The hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error
What are the 3 things you need to know for Student’s t test?
- The mean of populations 1 and 2
- The standard deviation of populations 1 and 2 squared
- The total number of values in samples 1 and 2
In t tests, what goes on the top of the equation?
mean 1 - mean 2
In t tests, what is square rooted?
(standard deviation 1 ^2 / total number of values in sample 1) + (standard deviation 2 ^2 / total number of values in sample 2)
THIS GOES ON THE BOTTOM OF THE EQUATION
What would be the value of a perfect no correlation coefficient?
0
What would be the value of a perfect positive correlation coefficient?
+1
What would be the value of a perfect negative correlation coefficient?
-1
What are the 3 types of adaptions?
Anatomical
Behavioural
Physiological
What are anatomical adaptions?
Physical features
What are behavioural adaptions?
The way an organisms acts (can be learnt or inherited)
What are physiological adaptions?
Processes that take place inside an organism
2 examples of anatomical adaptions
Camouflage
Teeth shape
2 examples of behavioural adaptions
Seasonal behaviours (e.g. hibernation) Survival behaviours (e.g. playing dead)
2 examples of physiological adaptions
Poison production
Temperature regulation
What are analogous structures?
Features on different organisms that perform the same role but their structures are very different
What is convergent evolution?
When unrelated species being to share similar traits
What causes convergent evolution?
Because the different organisms adapt to the same selection pressure (e.g. environment)
What are selection pressures?
Factors that affect the organism’s chance of survival (e.g. high temperatures)
What is the bottleneck effect?
When a drastic reduction in population occurs, leaving a small number of remaining organisms, which reproduce to create population with low genetic diversity/variation
What is the founder effect?
When a small subset of a large population is used to establish a new population, which will have low genetic diversity/variation
