Unit 2 - biodiversity Flashcards
What are the three levels of biodiversity?
Genetic, species, ecosystem
What is genetic diversity?
the sum of all the different traits/characteristics found in a species (sum of all the different genes found in a species)
- high genetic diversity (sexual reproduction) allows for better chances of survival due to higher adaptability rates
- lower genetic diversity (asexual reproduction) more susceptible to diseases pray etc
The sum of all the different genes in a species?
Genetic diversity
What is species diversity?
Variety of species found in an area
- ecosystems = connections between species, therefore higher species diversity = healthier ecosystem (also helps survive environmental changes)
Variety of species found in an area
species diversity
What is ecosystem diversity?
Total number of habitats and organisms in an ecosystem, including all the connections between them.
- ecosystems can be large or small, eg. humans are a ‘walking ecosystem’
total number of habitats and organisms in an ecosystem, including all the connections between them.
ecosystem diveristy
Masss extinction?
Occurs when over 70% of living things die (we are currently in the midst of one)
definition of classification?
grouping similar things for a specific reason
Why do we need to classify?
- understand evolution and relationships between species
- Properly name-new organisms (and determine whether they are actually new)
- distinguish between harmful and non harmful organims
History of classification?
- Untill the 1800’s eveything was classified as either a plant or an animal
- plant (consitantly grew, didnt eat other organisms, did not move)
- animal (grew untill a certain point, moved, ate other things) - Around the 1990’s it expanded into 5 kingdoms
- protists
- fungi
- animals
- plants
- monera (microscopic organisms)
Current classifications/kingdoms
- plants
- animals
- protists
- fungi
- archaebacteria
- bacteria
*1234 are eukaryotes, 56 are prokaryotes
How do we classify organisms?
- Number of cells
- multicellular/ uni-cellular - Nutrition
- autotroph/heterotroph - Habitat
- where does it live? - Type of cell
- eukaryotic/prokaryotic - reproduction
- sexual/asexual
What are the domains?
- Archeabacetria (only contains archeabateria)
- Eubacteria (only contains bacteria)
- Eukarya (plants, animals, protists, fungi)
What is a species?
Organisms that are able to freely breed under natural conditions and produce fertile offspring (similar structure)
Morphology
species that produce asexually
Hybridization
The exception to the species rule. Two different species crossbreed
Who is the father of taxonomy ratings/the inventor of the binomial nomenclature?
Carl Linnaeus
Taxonomy ratings
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
- it becomes more specific down the list
Binomial nomenclature?
Genus, species
eg. Canus, lupus
Genus is capitalized. Species are lowercased. If typing, italicized, if writing, underline
Dichotomous key
- a list of yes or no questions that scientists can use to classify different relatedness
- used to classify and identify species
- looks like a family tree when graphed
What is the history of a species based on?
- molecular genetics
- the iBOL uses a barcode system to scan a species DNA - Development similarities
- similar embryonic stages suggest that organisms evolved from one thing
- ie. All vertebrae have gills during the early embryonic stages, suggesting that they all came from one common ancestor - Structural similarities
- similar structures but different functions (eg. bone structure in legs)
Homologous structural similarities?
Same anatomical structure, different functions
Analogous structural similarities?
Same anatomical structure, same functions (ie. like wings in bats vs birds)
phylogenetic tree/cladogram and structure
- diagram that displays evolutionary links between organisms
- tips represent different species (if a tip doesn’t make it to the top that means its extinct)
- nodes represent common features such as vertebrae, fur development, etc. At each node there is a common ancestor implied as well)
phylogeny?
evolutionary relationships between species
What are clades?
Clades are groupings on a cladogram that share a common ancestor/node (they make a triangle)
- this generally means they are more genetically similar
definition of taxonomy?
The science of classifying things
Archea and bacteria similarities?
- both prokaryotes (no membrane-bound organelles, no membrane-bound nucleus)
- very small, only have a cell membrane and nucleus (DNA and ribosomes are free-floating)
- they both have one kingdom and domain
Archea and bacteria differences?
- different genetic lineages (separate domains and kingdoms)
- archea are considered ancient and live in extreme climates (live off ammonia)
- certain bacteria can make us sick, archea cannot infect us
- different cell walls and DNA
Archea bacteria
- prokaryotes
- single celled
- replicate by binary fission
- heterotrophic or autotrophic
- ancient
- live in very extreme climates such as volcanoes vents and hot acids
- EXAMPLES:
anaerobic methanogens (oxygen free, produce methane)
haliophiles (live in salt lakes)
Thermophiles (live in really hot conditions)
Bacteria
- prokaryotes (largest number on earth)
- single-celled
- replicate by binary fission
- heterotrophic/autotrophic
- they go through conjugation in which they share DNA to make other cells smarter
- important for the carbon/oxygen cycle (nirtogen fixation and decomposition)
EXAMPLE: Ecoli
Protists
- eukaryotic
- autotrophs or heterotrophs
- multicellular or single-celled
- reproduce sexually or asexually through binary fission
- kind of like the ‘catch all’, they just don’t fit into any other category
(plant like, animal like, fungi like)
-require a wet/moist environment - no cell wall
EXAMPLE: algae, protozoa
Fungi
- eukaryotic
- heterotrophs
- multicellular
- sexual and asexual
- cell wall isn’t made out of cellulose (made out of chitin, they dont have any chloroplasts)
- terrestrial
EXAMPLE: mushrooms, mold
Plants
- eukaryotic
- autotrophs
- multicellular
- sexual and asexual reproduction
- cell wall made out of cellulose (has chloroplasts)
- terrestrial and aquatic
EXAMPLE: flowers, ferns, trees
Animals
- eukaryotic
- heterotophs
- multicelular
- sexual and asexual reproduction
- terrestrial and aquatic
EXAMPLE: Fish, human
describe/ draw a prokaryotic cell
- chromosomes are unwound (thread-like), gathered in the center of the prokaryotic
- free-floating ribosomes (that look like dots)
- no membrane-bound organelles
- circular rings of DNA called plasmids
- contains pilus (string hairs)
Bactera structure
- very small (1-10 um)
- no membrane bound organelles
- contains cell wall and membrane
- free floating unwound chromomsome in the nucleic region
- free floating ribosomes
- plasmids
- could have a flagella
Bacteria shapes
- coccus (round)
- monococci (singular, round)
- diplococci (two, round)
- streptococci (string, round)
- staphylococci (bunch of them)
- bacillus (rod)
- monobacilli (singular rod)
- diplobacilli (two, rod)
- streptobacilli (string, rod)
-spirillum (spiral shape)
What are gram stains? how are they used? give examples
Gram stains are made from crystal violet and iodine. They are used to categorize bacteria into two groups:
- Gram positive
- turn purple
- have a thinner cell wall/membrane
- less pathogenic (more susceptible to antibiotics) - Gram negative
- remain their original colour
- cell wall/membrane is thicker
- more pathogenic (resistant to antibiotics)
Nutrition
why is it needed/what is it
name the different categories of bacteria nutrition
- Bacteria cells obtain nutrition from a source of carbon dioxide and an energy source
- photo autotroph
- sun (energy) co2 (carbon) - Chemoautotroph
- inorganic chemicals (energy) co2 (carbon) - Photoheterotroph
- sun (energy) organic compounds (carbon) - Chemo heterotroph
- organic compounds (energy) organic compounds (carbon)
Name all the different forms of bacteria respiration
- Aerobes (require air)
- obligate aerobes (absolutely need air) - Anaerobes (do not require air)
- obligate anaerobes (die with air) - Facultative aerobes/anaerobes (don’t care)
Binary fission (bacteria). Mutations?
- occurs in bacteria, archaebacteria, some protists
- asexual method of reproduction
- quicker than mitosis (skips a lot of steps, can be done in 20 min)
- Parent cell copies DNA
- Parent cell continues to grow and cells divide
- Two exact daughter cells are created
Mutations are rare, but because there are so many bacteria they tend to occur quite often. They are what cause genetic diversity in bacteria.
Conjugation
- occurs in bacteria, archaebacteria, some protists
- makes cells smarter
- in tough conditions, some cells are able to survive better than others due to the DNA on their plasmids (it can code for a stronger cell wall etc)
- cells can share their plasmids and help other cells survive
- A cell that doesn’t have a plasmid finds a cell that does (chemical reactions)
- The two cells connect via their pilus (protein bridge)
- Plasmid copies itself, unravels, and goes through the hollow protein tube created by the pili
- The two cells unattached, one cell now has a different genetic makeup
Endospores
When a gram-positive bacteria undergoes very bad conditions, it can create an extremely thick cell wall around itself and stay dormant until conditions get better (made from spores)