Exam 3 Flashcards
what is special about bacterial cells?
They have no membrane bound organelles
What is a characteristic that bacteria independently evolved?
Peptidoglycan cell walls
What is a characteristic that was developed independently by archaea and eukarya?
histones
What are histones?
Protein in which DNA wrapped around.
What is horizontal gene transfer?
Movement of DNA from different strains and species
What is the benefit of horizontal gene transfer?
Major source of genetic diversity in bacteria.
What is conjugation?
DNA directly transferred between bacteria
What is transformation?
DNA taken up from growth media.
What is transduction?
DNA transferred by virus
What blends the phylogenetic tree of bacteria?
Horizontal gene transfer
What does metagenomic analysis allow?
Quantitative analysis, molecular clock, and allows phylogeny when it is hard to culture organisms
What is a characteristic that was independently created by archaea?
Branched hydrogens in plasma membrane.
What are characteristics that were independently created by eukarya?
Multicellularity, nuclear membrane, linear chromosomes
What is unique about archaea?
Very small and have antibiotic resistance
What are extremophiles?
They can live in high salt, high temp, low temp, high pressure, and high acidity.
What is the missing link in eukaryotic evolution?
Archaea with eukaryotic biochemical pathways.
What are the 4 criteria under Koch’s Postulate for germ theory?
- microbe must be present in affected and absent from unaffected.
- microbe must be isolated and grown in pure culture.
3.If inject pure culture into healthy individual, disease will result. - must be able to culture microbe from the newly infected individual
What does cyanobacteria release?
bubbles of oxygen
What is the energy and carbon source of a photoautotroph?
Light and CO2
What is the energy and carbon source of a Chemoautotroph?
Inorganic compounds and CO2
What is the energy and carbon source of a photoheterotroph?
light and organic compounds
What is the energy and carbon source of a chemoheterotroph?
both are organic compounds
What do microbial mats produce?
sharp gradients of light and oxygen
What are stromatolites?
Fossilized layers of microbial mats that are as old as 3.5 billon years old
What are the characteristics of deep sea hydrothermal vents?
No photosynthesis and chemoautotrophs
What are heterocyst?
Allow cyanobacteria to fix nitrogen in the presense of oxygen
How does eutrophication from excess nutrients work?
Soil bacteria remove added nutrients that can damage aquatic ecosystems.
What is the function of the nuclear membrane?
Separates transcription from translation.
What is the function of membrane bound organelles?
Compartmentalize biochemical reactions, perform molecular packaging and transport, and perform endocytosis and exocytosis.
What is the function of the cytoskeleton?
Controls the cell shape
What is endocytosis?
phagocytosis
What is the endosymbiosis theory?
Nuclear genes resemble archaea and mitochondrial genes resemble protobacteria
What are the eukaryotic signatures in asgard archaea
Membrane infolding, a cytoskeleton, and eukaryotic biochemical pathways
What group are protists?
paraphyletic
What are the important characteristics of protists?
presence, absense, and form of mitochondria and chloroplasts
cell structure
flagella characteristics
What are protozoans?
Protists that ingest their food
What are slime molds?
decomposers
What are unicellular algae?
Diatoms, 50% of ocean photosynthesis, silica tests
What is the evidence of primary endosymbiosis?
- Chloroplast DNA similar to cyanobacteria
- Two linked photosystems for photosynthesis
3.Chloroplasts have 2 membranes(one from cyanobacteria and one from eukaryotic host)
What is secondary endosymbiosis?
Chloroplast has 4 membranes
2 form chloroplast
1 from first host
1 from second host
What are the synapomorphies of fungi?
Cell walls that contain chitin, single smooth flagellum, and store sugar as glycogen
What do mycorrhizae fungi do?
Form mutualism with plants
What are saprophytes?
Decompose dead matter, breakdown ligin and cellulose
What is special about multicellular hyphae?
Has the highest surface area to volume ratio of any eukaryote.
What are the fruiting bodies in fungi?
Reproductive structures made of hyphae.
Where are fungal spores released from?
From the sporangia or sporangium.
What is the fungal life style of fungi?
Refer to picture on slides from class.
What is plasmogamy?
Fusion of the cytoplasm.
What is karyogmay?
Fusion of the nuclei.
How are fungi classified?
Based on spore producing structures.
What are chytrids?
Fungi that have flagellated spores and live in aquatic environments.
What as an example of a chytrid infections?
Harming of frog populations.
What are zygomycota?
zygote has a tough outer coat.
What are basidiomycota?
make pedistal like basidian. Also referred to as club fungi.
What are ascomycota?
make a sac like ascus.
What are lichens?
mutalism between fungi and green algae (or any cyanobacteria)
What are the plant distinguishing features?
Multicellularity, Photosynthetic(chlorophylls a and b plus carotenoids in thylakoid membranes), store food as amylose starch, cell walls made of cellulose, life cycles, diploid sporophyte, and haploid gamephyte.
What are the ecological roles of plants?
Base of food chain, produce O2, habitat, build and hold soil, hold water, moderate local climate.
What are the advantages of living on land as a plant?
More light and CO2
What are the disadvantages of life on land as a plant?
Dry environment, resources are separated, and gravity
What were the land adaptations for land plants?
Waxy cuticle, stomata, reproductive spores, vascular system, ligin
What is a gametophyte?
Haploid that makes gametes
What is a sporophyte?
Diploids that make spores
What is the green alga life cycle?
Refer to class slides.
What is the land plants life cycle?
Refer to class slides.
What is special about the moss life cycle?
The gametophyte is dominant. (spores protected by sporopollenin)
What are non vascular plants.
no vascular tissue to conduct water or provide support.
What does sphagnum moss do?
Holds water and heat.
What are the vascular plants without seeds?
Lycophytes, ferns, and horsetails
What is special about the fern life cycle?
The sporophyte is dominant
What cycle is dominant in the angiosperm?
The sporophyte
What is the evolutionary trend of plants when it comes to reproduction?
Reduction of the gametophyte.
How do you spot at monocot?
One cotyledon, vascular tissue scattered in stem, parallel veins in leaves, petals in multiples of 3.
How do you spot a eudicot?
Two cotyledons, vascular tissue in circular arrangement in stem, branching veins in leaves, petals in multiples of 4 or 5
What is the function of leaves when it comes to water transport?
Maximize CO2 uptake while minimizing water loss
What is solute potential?
water movement by osmosis
What is pressure potential?
Water movement by pressure
What is the opening of the stomata caused by?
Light, low CO2, internal clock
What is the closing of the stomata caused by?
Water shortage, high temperatures
How do stomata open and close?
Movement of water into/out of guard cells by the water potential changing in the guard cells.
What does the proton gradient control in guard cells?
water potential
How does water potential work?
By flowing from a high water potential to a low water potential
What is the xylem?
Vessels in which water is transported through in plants
What is the endodermis?
the gatekeeper of the waters pathway into the plant
What is the xylem structure?
Lignified secondary walls, dead at maturity, and water transport and support
What are the 3 hypothesis for water moving up trees?
Root pressure, capillary action, and cohesion tension theory.
What is root pressure?
Water pushed up from roots because the root cells actively accumulate ions which causes a low water potential in root cells
What is transpiration?
Pull created by transpiration down to roots by H bonds.
How does gas exchange work in plants?
Leaves convert CO2 in sugar, O2 waste product
What is the flow of sugar in plants?
Flow from leaves to other plant parts. Transport in phloem. Flows from sources to sinks. And direction can change.
What is the phloem structure?
Sieve tube members(no nuclei, few organelles), sieve plate(pores between STM’s), and companion cells
What does phloem cells contain?
30% sugar, minerals, AA’s, hormones, RNA, Water
How does the transportation of the sugar from the source to the sink work?
Active transport loads sugar to companion cell/STM
Low water potential at source STM then water flows in from xylem creating pressure
Then sugar removal at sink causes water potential to increase so water returns to xylem
How does phloem unloading work?
When depositied into growing leaves it is converted to ATP. In storage roots, sucrose is stored in vacuoles.
What can plants sense?
light, gravity, day length, temperature, physical touch, damage
How does signal transduction work?
- External stimulus
- phosphorylation
- Secondary message produces phosphorylation cascade and a calsium 2nd messenger
- Cellular response
What is phototropism?
Movement in response to light
Were are the light receptors located?
In the tip cells
What is a hormone?
Signaling molecule transported though an organism
What are the steps in information processing?
- Signal transduction in receptor cell goes to an intracellular signal.
- Hormone synthesizes or is redistributed.
- Then it is turned into a response
How do hormones cause bending?
by elongating cells
How does the stimulus and phosphorylation of membrane proteins work?
Phototropin is phosphorylated and then the hormone is redistributed.
What happens when red light hits phytochrome?
it changes shape to allow for germination and is opposite when far red light hits phytochrome.
How is flowering time affected?
By day length
Where does auxin promote elongation and where does it inhibit cell elongation
Promotes in shoot and inhibits in roots
What is positive gravitropism?
The root growing in towards gravity
What is negative gravitropism?
The shoot growing against gravity.
What is the definition of gravitropism?
Movement in response to gravity.
Where does gravity sensing occur?
Occurs in the root cap
What is the statolith hypothesis?
Starch grains help the plant sense gravity
What is thigmotropism?
Response to touch
How do the stomata open?
When light strike the stomata a proton pump creates an electrochemical gradient.
Ions then enter along a concentration gradient and water follows by osmosis causing swelling and the stomata open
What does auxin do when it is produced in the apex?
Suppresses lateral bud growth
Where are the pin transporters located in the polar transport of auxin?
Located on the basal side of the cell which is towards the root.
What is abscisic acid?
Signaling chemical for plants
how does abscisic acid cause the stomata to close?
Causes the proton pump to stop, stopping the gradient
What do cytokinins do?
Regulate cell division
What is the role of cytokinins?
Promote lateral shoot growth and are produced in the roots.
What are two roles of gibberellins?
Stimulate growth and internode elongation causing large fruits
What is ethylene?
The aging hormone used to cause fruits to ripen, flower, and leaves to fall of
What do healthy shoots produce?
auxin and ethylene
What happens if a leaf is staying on its stem?
It is weak and has little auxin
What happens when a leaf has a lot of ethylene?
It goes through abscission
What is hypersensitive response?
A plant cell recognizing a pathogen and secreting chemicals and messages causing the plant to kill the pathogen and the plant cell. This also thickens the plant cell wall.
What is systematic acquired resistance?
When one leaf is infected it passes a defense message to that no other leaves can be affected.
What are the 3 ways a plant defends against herbivory?
Mechanical, mutualism, chemical, and inducible responses
What are the 3 plant organs?
Leaves, roots, stems
How is the shoot organized?
leaf, nodes, and internodes
What are the 4 different leaf forms?
Simple, compound, doubly compound, needlelike
What are the 4 different leaf arrangements?
Alternate, opposite, whorled, rosette
What are the different types of modified leaves?
Protection, climbing, predation, attract pollinators, storage
What is the function of stems?
Support for light access and sexual reproduction. Transport water and minerals.
What are the different functions of modified stems?
Water storage, starch storage, protection, and asexual reproduction
What is the function of roots?
Water uptake, nutrient uptake, anchorage, storage
What are the different type of roots?
Fibrous(lateral), taproots
What are the different type of modified roots?
Anchoring, prop, storage, pneumatophores
How do plants compensate for being non-motile?
Have a high surface area exposed to the environment to gather diffuse resources.
What is intermediate growth?
Capable of growth throughout life.
What are meristems?
They are perpetually young cells that in primary growth add length, and secondary growth add girth
What is the root structure?
Zone of cell division, zone of cell elongation, and zone of cell maturation.
Where does secondary growth take place?
In the lateral meristems to promote girth and only happens in woody plants
What does the vascular cambium do?
Produces the xylem and phloem
What does the cork cambium do?
Produces outer bark
What does each ring on a tree represent?
1 year of secondary growth
What do wide growth rings represent?
good growth conditions
What do narrow growth rings represent?
Poor growth conditions
How does the vascular cambium move when more xylem is added to the inside?
Outward
What is the function of the lenticels?
Allow for O2 to diffuse through bark
