Module 4 Flashcards
what are the levels of classification?
Domain Kingdom phylum class order family genus species
why do we classify organisms?
to identify species
to predict characteristics
to find evolutionary link
What is a species?
A group of organisms that can produce fertile offspring
why can’t animals like mules produce fertile offspring?
because they have an odd number of chromosomes, so they can’t pair up properly during sexual reproduction
what is the name of the system we use to name organisms with their genus, species
Binomial nomenclature
what are the characteristics of Prokaryotes
unicellular
no nucleus/ membrane bound organelles
ring of DNA
nutrients absorbed/ through photosynthesis
what are the characteristics of protists?
mainly unicellular nucleus and membrane bound organelles some have chloroplasts can sometimes move by flagella can be parasitic, heterotrophic or autotrophic
what are the characteristics of fungi?
uni or multicellular chitin cell wall nucleus and membrane bound organelles no chloroplasts can't move store foo as glycogen nutrients absorbed from decaying material
what are the characteristics of plants?
multicellular chloroplasts and cellulose cell wall nucleus and membrane bound organelles do not move autotrophic store food as starch
What are the characteristics of animals
multicellular no cell wall membrane bound organelles can move with flagella/ contractile proteins heterotrophic food stored as glycogen
what size ribosomes do each of the 3 domains have?
Eukarya- 80s
Archaea- 70s
Bacteria- 70s
What is the difference between Archaea and Bacteria>
Archaea have RNA polymerase with 10 proteins, whereas Bacteria have 5. Archaea also can live in extreme conditions.
what is phylogeny?
Evolutionary relationships between organisms
What is a phylogenetic tree?
A diagram used to represent evolutionary relationships between organisms. They show that different species have evolved from a common ancestor.
How do we find most evidence for phylogenetic trees?
fossils
what is an advantage of phylogeny?
provides a continuous tree, instead of discrete groups
What are the three main pieces of evidence for evolution?
paleontology
comparative anatomy
comparative biochemistry
how do fossils provide evidence for evolution?
The least complex fossils are found in the oldest rocks, showing life became more complex as time passed
We can see similarities in anatomy of fossils to show that closely related animals have evolved from a common ancestor.
How does comparative anatomy provide evidence for evolution?
homologous structures show that many organisms came from the same ancestor and therefore share similar structures, but have evolved to perform different functions
How can we use comparative biochemistry to provide evidence for evolution?
Neutral changes in a molecules structure (has no effect as not in functional group, and therefore isn’t affected by selection pressures) happen regularly. finding the difference between molecules from two species and plotting against the known rate of neutral mutations shows how long ago they last shared a common ancestor
What are the two types of variation?
Interspecific- between species
Intraspecific, between organisms in a species
what are the two causes of variation?
genetic and environmental
what are the genetic causes of variation?
different alleles for the same gene mutations meiosis sexual reproduction chance
when are the students t test and spearman’s rank used?
t test- comparing means of two populations
spearman’s rank- to consider a relationship between two sets of data
what are the three types of adaptations?
anatomical
behavioral
physiological
list some anatomical adaptations
body covering- hair/feathers, shell, waxy cuticle
Camoflague
teeth
mimicry
How is marram grass adapted to its environment?
curled leaves to minimise surface area exposed to air
hairs to trap moist air
stomata sunk into pits
thick waxy cuticle
list some behavioral adaptations
playing dead
courtship
migration
hibernation
What are the two types of behavioral adaptations?
innate and learned behaviour
List some physiological adaptations
poison production
antibiotic production
water holding
what is an analogous structure?
where something from two different organisms carry out the same role, but have very different structures
what is convergent evolution?
where unrelated species begin to share similar traits, due to adapting to similar selection pressures
describe the process of natural selection
Organisms within a population show variation
Organisms whos characteristics are best suited to a selection pressure are more likely to survive and reproduce
Allele for advantageous characteristic more likely to be passed on
Process repeated over time, increasing gene frequency in the population
Over many generations and involving many genes, this can lead to a new species
what are some modern examples of evolution?
MRSA
peppered moths
sheep blowflies
flavobacterium
what are the three different levels of biodiversity?
Habitat
Species
Genetic
What is habitat biodiversity?
The number of different habitats within an area, this generally leads to an increase in species biodiverasity
What are the two types of species biodiversity?
Species richness- number of different species in an area
Species evenness- a comparison of the number of individuals of each species living in a community
What is genetic biodiversity?
The variety of genes that make up a species. Genetic biodiversity within a species can lead to very different characteristics being exhibited. More genetic diversity allows better adaptation to change
What are the two types of sampling?
Random and Non-random
What are the types of non random sampling?
Opportunistic- weakest as not representative. Sample organism that are conveniently available
Stratified-Broken into mutually exclusive strata and sample taken from each strata
Systematic- Can be line transect where taking samples at points along a line, or belt transect, where two parallel lines marked and samples taken of area in between
Why might sampling not be reliable?
Sampling bias- can be accidental or on purpose, can be reduced by using random sampling
Chance- Organisms selected may not be representative of whole population. Can be minimised by larger sample size
How can we sample animals?
A pooter can be used to suck insects in with a mouthpiece
Sweep nets
Pitfall traps
Tree beating
Kick sampling- kick a river bed and use a net to catch organisms flowing down the river
how can we sample plants?
Point quadrat- frame with bar with holes at set intervals. Pin pushed through and anything touching the pin is sampled
Frame quadrats
In what ways can frame quadrats be used to sample plants in a habitat?
Density- counting number of plants
Frequency- How many times a plant is present in a number of trails (65 out of 100 samples contained at least one buttercup, so frequency= 65%)
Percentage cover- estimate by eye
How can we estimate animal population size
Capture-mark-release-recapture
What abiotic factors can we measure and with what sensor?
wind speed- anemometer light intensity- light meter relative humidity- humidity sensor pH- pH probe temperature- thermometer oxygen content- oxygen probe
What are the advantages of using sensors to measure abiotic factors?
Rapid changes can be detected
Human error reduced
High precision
Data stored and tracked on computer