chapter 1(spec, phylo, taxo, bac +archae) Flashcards
what are the 4 concepts used to define species
morphospecies concept, ecological species concept, biological species concept and phylogenetic species concept
explain the morphospecies concept and why it’s not ideal
based on physical appearance, differentiate species this way
not ideal because in many species the male is more colourful than the female. for example male and female peacocks. if you’ve never seen one before, you might think that they’re different species
explain the ecological species concept and the issues with it
based on their niche (where they are found and what resources they use.)
the problem with this can be overlapping niche they are many bacteria that live in the same environment (dirt) and eat similar things
explain the biological species concept and what issues it has
based on their ability to sexually produce with one another and create fertile offspring
Problems: not all organisms reproduce asexually, for example bacteria. What if they live in different environments and don’t cross paths. For example the elephants in grassland vs forest. Can’t know if different species
explain the phylogenetic species concept and what issues it has
use DNA to see how much the DNA of two organisms lines up
-problems: we don’t have the DNA sequence of every species we know about. The elephants are diff species because we know DNA is very different. Helps solve biological species concept and morphospecies concept. The tusks of the elephats are different
what are subspecies? what are hybrids?
subspecies are organisms that have evolved in isolation and have distinguishing physical characteristics. an example of this is orangutans. some hair more hair and different hand sizes
hybrids form from the mating of two closely related species which may or may not result in the formation of a new species. An example of this is ligers
what are the different evolutionary forces?
mutations, natural selection, genetic drift and gene flow
describe mutation and its role in speciation
changes in nucleotide sequence in alleles.
It creates a new allele which can spread throughout the population. can say it contributed to evolution if the population all changes to that specific gene
explain natural selection and its role in speciation
when the environment increases beneficial alleles and decreases harmful ones (the beaks of birds on Galapagos).
can eliminate harmful alleles and create new species/subspecies
genetic drift vs gene flow and roles in speciation. What is fixation?
genetic drift is when there are random changes in existing alleles due to chance events. can lead to extinction purely by chance
Fixation is when 100% of the population has the allele, extinction is when that allele disappears from the population
gene flow is the mixing of alleles between populations due to migration of individuals from one population to another
affects speciation: if gene flow is elimatinated you get a new species.
GENETIC DRIFT AND GENE FLOW WORK TOGETHER IN THE FORMATION OF NEW SPECIES
Explain and provide examples of allopatric and sympatric speciation. Be able to explain why sympatric speciation is less common
allopatric speciation: when a new species forms in different geographic locations (ex: Galapagos finches that flew to the island because some got blown off course); this is genetic drift not gene flow)
sympatric speciation is when a new species forms in the same geographic area. ex: fruit flies using berries to reproduce, eventually some using apples to continue on life cycle
Sympatric is less common because They are in the same environment and there is gene flow. They are interbreeding. So takes a lot longer to eliminate intermediate species. Still gene flow, but genetic drift makes more sense
what are some things to do when evaluating phylogenetic trees
Be caustious about where branching points are. Never count the number of nodes, doesn’t tell u if closer or not as close related. Focus on where node is in relation to time. Share common ancestor at this point in time therefore turtles and mammals are equally related. Makes sure point to node and time
branching point vs position of nodes
branching point is a speciation event and represents a common ancestor for all subsequent species,
position of nodes relative to time can be used to show how closely related species are to one another
true or false the number of nodes between a common ancestor and a descendant is an indicator of relatedness
false
explain homologous vs analogous structures
inherited traits from a common ancestor. like our vertebrae and the vertebrae of monkeys are similar because we share a common ancestor. sometimes not useful.
analogous structures are when organisms have different ancestors but they have structures that serve the same function
like leg of horse and leg of ant, made of different things but serve the same function. don’t have common ancestors
what do we call structures that we don’t use anymore
vestigial structures
what is an outgroup
a species or group of species that is closely related to but not part of the group
what is taxonomy and why is it important
the branch of biology that deals with classifying species according to their morphology and phylogeny. It’s important because there are so many different species and it’s a good idea to organize them to keep track of all of them
what are all the levels of classification and how do you remember them
Domain, Kingdom, Phylum, class, order, family, genus, species
dutch kings play chess on finely ground sand
why are the terms in latin
- each part of latin word has meaning. 2. because no longer being used, the meaning of the words no longer change. 3. all scientists agree upon this language
what are the 3 domains of life? describe each
- bacteria which is the most diverse, most widespread and most common prokaryotes
- archaea are rare ancient prokaryotes that are in a different domain because they live in very hostile environments like geysers
- eukarya are protists, animals and fungi
how do you tell between protists, animals and fungi
fungi and animals are heterotrophs. fungi. put saliva all over their food. break things down externally. animals break down food internally. fungi don’t move but animals do.
what is the purpose of classification
allows to organize all species in logical manner, giver information about common features, mammals have hair and are heterotrophs, allows for naming every organism in the universe
how do you write out the scientific name fo organisms
Ø Scientific name is written in italics or underlined and consists of two parts:
Ø Genus name is written first and the first letter is capitalized.
Ø Species name follows the genus name and is not capitalized.
Ø Give specific examples of scientific names.
bacteria and archaea are prokaryotes what does this mean
they lack membrane-bound organelles and have a very simple structure
which types of archaea / bacteria are not unicellular
Cyanobacteria. They stay linked together as binary fission occurs (cell division)
they have chlorophyll which allows them to carry out photosynthesis and are multicellular
these cell evolved and raised oxygen levels of the world
some bacteria/ archaea have a slimy capsule and hair like fimbriae. what are the functions of this?
- protection-repels invasion and also stick on the surface
- adherance- Increases the surface area to anchor onto cell
- hides better - hides in our immune system so we cannot detect it
what are the distingushing features of bacteria, eukarya and archaea
Bacteria has a cell wall made of peptidoglycan, but lacks histone
eukarya doesn’t have histones, but has a resistant plasma membrane
archaea doesn’t have a cell wall or histones
what are bacteria cell walls made of. Why?
peptidoglycan which is linked glucose and is the strongest cells walls
what organism has resistant plasma membrane? explain
archaea,
have esther bonds/linkages. it lacks additional oxy aton making it less likely to undergo hydrolysis
- the branched amino acids make it harder for moleculesto get across which makes it less leaky and less permeable
what are endosperms and what produces them
bacteria produce them. endospores are a copied version of a bacteria that traps the DNA of the bacteria in an egg and keeps the genetic data of the bacteria until the environment is safe for the bacteria again
differences between bacteria and archaea and eukarya
bacteria have one circular DNA molecule with no introns and no histones- archaea and eukarya are different. no histones because the cell organizes and compacts the DNA
archaea has circular DNA but has introns and histones
what are the benefits of having circular DNA
- can be copied faster
- no need to separate from histones
- no detachment from DNA
the ribosomes of bacteria and archaea are smaller than eukarya. explain
the ribosomes of bacteris have 3 RNA strands and proteins.
the ribosomes of eukarya have 4 RNA strands and proteins
why are the flagella of bacteria and archaea different?
because they’re an analogous structure
true or false bacteria divide through binary fission and have no microtubules / spindle fibers
true
why are the divisions of bacteria so rapid? What are the disadvantages of this?
the circular DNA is easier copy and has no introns. This makes the DNA easier to replicate
Disadvantages are that all cells are identical so there is no genetic variation which makes it hard to survive if there is a change in their environment
They are also susceptible to antibitotics
what is conjugation
the one-way transfer of a copy of a small, circular DNA molecule (called plasmid) through a tube like connection (called pilus)
creates a cytoplasmic bridge to transfer genetic information exhange
what is the advantage of conjugation
it allows for genetic variation so that they can become antibiotic-resistant. creates a new coding for a capsule
plasmid vs pilus
Conjugation is the one-way transfer of a copy of a small,
circular DNA molecule (called a plasmid) through a tubelike connection (called a pilus)
what are the 5 different types of shape that bacteria can have? describe them
cocci: cylinder/ ball shaped bacteria
Bacilli: rod shaped bacteria
spirochete: spirally with internal flagella that allows them to move around in different environments
spirilla: squiggly with external flagella
vibrios: comma shaped / curved
classification of bacteria based on arrangements (3 kinds)
diplo - pairs
strepto - exist in chains
-staphylo- exist in clusters
gram-positive vs gram-negative bacteria
gram- positive:
stains purple because thick peptidoglycan cell wall makes the stain hard to wash out
(also has plasma membrane)
Gram-negative:
bacteria stains pink, are much more dangerous because have hair like structures that can be poisonous by contact, can produce capsil and has 3 layers to penetrate
what is a heterotroph?
bacteria that breakdown organic material of other organisms
what is an obligate aerobe
need to have oxygen because the final acceptor of electrons of the ETC
facultative anaerobes
can live with or without oxygen
what are saprotrophs
decompose spoiled food
parasites
opp of saprotrophs. feed on loving things, disease-causing bacteria
what are photoautorophic bacteria. Give a example?
make their own organic matter using sunlight and in the process release oxygen.
cyanobacteria deed oxygen to the earth, O3 makes up the ozone layer, so they made that too
what are chemoautotrophic bacteria
oxidize inorganic compounds (such as hydrogen sulfide (H2S) and ferrous ions (FE2+) to obtain energy. They are only found in bacteria and archaea
some examples would be bacteria found in the deep sea
Lyme disease. What causes it, how does it spread and what are the symptoms?
caused by spirochete bacterium, that is spread by ticks. most common symptoms is bulseye looking rash.
later break down cartilage in joints which is similar to arthritis, super late they feed on the brain
necrotizing fasciitis. what causes it, symptoms and how does it spread?
caused by gram-positive streptococcal bacterium. spreads is that when you get a cut, the endospores get into the cut. once in suitable environment will become active
tetanus. What causes it, how does it spread and what are the symptoims
caused by obligate anaerobic bacillus bacterium that thrives in deep wounds.
when you get cut goes into body and causes issues. also starts off as endospore on dirty knives or sharp metal,
symptoms are muscle spasm all over. die by larynx region collapsing because of the muscle spasms
what is nitrogen fixation and why is it important
carried out by bacteria. They break down the triple bond in Nitrogen so it can be used for other things by plants. break it down using enzymes.
These plants then provide these bacteria a home in their root nodules.
bacteria and archaea breakdown the cullelose of plant cell walls in the digestive tract of herbivores. What role does it play in our digestive
the bacteria in our intestine, one that makes vitamin K found in large intestine. protect against harmful bacteria.
bioluminescent bacteria live within organs of deep-sea marine life. What is the purpose of this
they can use to attract mates, attrack prey, scare/ confuse predators
what is bioremediation
using living organisms to bring the environment back to normal state. Spread nitrogen and phosphate to feed bacteria that then feed on oil spills
why do bacteria produce antibiotics
they make natural antibiotics to prevent other organisms from getting close/ taking their food “zone of inhibition”. we then take their antibiotics and put them into our own
how are bacteria important in food production
allow us to make cheese, pickle and yogurt
