exam 2 Flashcards
what are the general phases of the cell cycle
- interphase
2. M phase
interphase
- normal cell activity
- majority of cell’s lifetime
- prep for cell division
- DNA is loose chromatin
what are the three stages in interphase?
- G1 aka gap 1
- S aka synthesis
- G2 aka Gap 2
G1
- cell growth
- protein synthesis
- water intake
S stage
- DNA replication
G2
- organelle replication
- chromosomes begin to condense into tight chromatids
M phase
division phase
what two events divide the entirety of the cell content in M phase
- mitosis
2. cytokinesis
what is mitosis
Nuclear division
what is Cytokinesis
cytoplasmic division
what happens during mitosis
- plant growth
- replacement
what are the 4 phases in the M phase
- Prophase
- metaphase
- anaphase
- telophase
Prophase (mitosis)
- chromosomes finish condensing
- sister chromatids are connected at centromere
- nuclear envelope fragments and dissociates
- spindle fibers attach at centromeres
metaphase (mitosis)
- chromosomes line up at spindle equator
anaphase (mitosis)
- sister chromatids separate
- pulled to opposite ends of the cell
telophase (mitosis)
- nuclear envelope reforms
- chromosomes decondense (return to chromatin)
- cell plate begins to form
when does cytokinesis begin?
- late anaphase/telophase
What occurs during cytokinesis
- telophase golgi vesicles create cell plate → becomes cell wall
- small bits of ER between vesicles → plasmodesmata
meiosis
- aka reduction division
- only occurs in specific cells of sporophyte
what happens during meiosis
- Start: parent cell with 2 sets of chromosomes
- End: 4 daughter unique daughter cells with half chromosome number of parent cell
zygote
- egg+ sperm
what are the 4 stages in meiosis I?
- Prophase I
- metaphase I
- anaphase I
- telophase I
Prophase I
- chromosomes condense
- synapsis (pairing of homologous chromosomes)
- nuclear envelope dissociates
- crossing over
Metaphase I
- homologous chromosomes line up at spindle equator (independent assortment)
tetrad
4 chromatids together
anaphase I
- homologous pairs separate
- pulled to opposite ends of cell as sister chromatids
telophase I
- cell plate forms
- nuclear envelope does not re-form
- chromosomes may or may not decondense
what are the 4 stages in meiosis II?
- Prophase II
- metaphase II
- anaphase II
- telophase II
Prophase II
- chromosomes condense (if necessary)
- spindle fibers attach
metaphase II
- chromosomes line up at spindle equator as sister chromatids
anaphase II
- centromeres split
- sister chromatids are pulled to opposite ends
telophase II
- chromosomes decondense
- nuclear envelopes re-form
- cell plates form four genetically unique daughter cells
ploidy
- number of chromosomes per set
Alternation of Generations
- Gametophyte (n) makes gametes (n)
- Fertilization (egg + sperm) creates a zygote (2n)
- Zygote grows into a sporophyte (2n)
- Sporophyte makes spores (n)
- Spores grow into gametophytes (n)
chromosome
- can be an individual sister chromatid or 2 sister chromatids together
haploid
- 1/2 the number of chromosomes
diploid
- full chromosome count
Autotroph
- self feeding
- producer
Heterotrophs
- other feeding
- consumers
what is another name for visible light?
white light
plant pigments
- chlorophylls (a, b, c) (mostly a)
- Carotenoids (carotenes & xanthophylls)
- Fucoxanthins - algae
- Phycobilins - algae &cyanobacteria
what colors do light reflect and why?
- reflects all light because none of the colors are absorbed
what is the equation for photosynthesis
- 6 CO2 + 12 H2O + light energy → C6H12O6 + 6 O2 + 6 H2O
- CO2 goes to C6H12O6
- H2O goes to O2
light reactions
- requires light
- occurs in thylakoid
what happens in the light rxns
- light goes into PS II and PS I
- electrons bounce around in PSII until they get to the antenna complex
- electron bounce up the antenna complex (kinetic energy)
- electrons get replaced in the antenna complex by the splitting of water
- electrons go into an ETC 1 start at Pq end at Pc
- electrons then bounce around PSI until they get to antenna complex
- bounce up antenna complex
- electrons get replaced in the antenna complex by the electrons in ETC 1
- electrons then get passed to Fd
- electrons then get used to make NADPH
PSII
- optimal wavelength: 680 nm
- works 1st
PSI
- optimal wavelength: 700 nm
- works second
Calvin Cycle
- Light not a requirement
- Carbon fixation
- occurs in Stroma
- Some players get recycled
what happens in the Calvin cycle
- Use 6 CO2 + 18 ATP + 12 NADPH to store energy in 2 molecules of G3P
what happens if there is too much O2 in plants
- photorespiration
what happens during photorespiration
- Fixing O2 to RUBP → no sugar, so no stored energy
CAM Photorespiration
- Use carrier molecule to temporarily store CO2 in vacuole
- Conduct (temporary)CO2 fixation at night
- No O2/CO2 competition (due to separation in timing of processes) but does require energy
Cellular Respiration equation
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP + heat
what are the three steps in cellular respiration
- Glycolysis (ATP)
- Pyruvate oxidation (no ATP) +Citric Acid Cycle (ATP)
- .Electron Transport Chain (ATP)
Glycolysis
Yield from each glucose:net gain 2 ATP, 2 NADH,2 pyruvate
Pyruvate oxidation & Citric Acid Cycle
- Yield from each pyruvate oxidized: CO2 and 1 NADH
- Yield from each acetyl CoA:CO2, 1 ATP, 3 NADH, 1 FADH2
Electron Transport Chain
- Yield for each NADH:3 ATP and H2O
- Yield for each FADH2:2 ATP and H2O
how much ATP is made in cellular respiration
36
What time of day do C3 plants do light rxns
Day
What time of day do C4 plants do light rxns
Day
What time of day do CAM plants do light rxns
Day
Location of light rxns for C3 plants
Thylakoid
Location of light rxns for C4 plants
Thylakoid
Location of light rxns for CAM plants
Thylakoid
What time of day do C3 plants do the Calvin cycle
Day
What time of day do C4 plants do the Calvin cycle
Day
What time of day do CAM plants do the Calvin cycle
Day
Location the Calvin cycle for C3 plants
Stroma
Location the Calvin cycle for C4 plants
Bundle sheath cells
Location the Calvin cycle for CAM plants
Stroma
Do C3 plants do CO2 management
None
Do C4 plants do CO2 management
Moved to bundle sheath cells
Do CAM plants do CO2 management
Stored in vacuoles
What options for photosynthesis do C3 plants have
- C3 photosynthesis
- photorespiration
What options for photosynthesis do C4 plants have
- C4 photosynthesis
- C3 photosynthesis
What options for photosynthesis do CAM plants have
- CAM Photosynthesis
- C3 photosynthesis
- C4 photosynthesis
What IS a species?
- Biological (interbreeding) species concept: different organisms are the same species if they can successfully breed together
- Morphological species concept: organisms that closely resemble each other are of the same species
What are the problems with the biological species concept?
- many plants have specific pollinators but can breed when an artificial pollinator is used
- many plants differ in bloom time but could potentially breed if in a greenhouse
- extinct plants don’t breed (so how can they be classified?)
What is the problem with morphological species concept?
phenotypic plasticity
-physical variations due to differences in light, water, pH, etc.
How do you classify a new species?
- Contact: International Botanical Congress
- Publish description in a journal generally available to the public
- Preserve a specimen (aka “type specimen”) in location generally available to the public herbarium
How to classify a new species via hybridization or selection?
- Name of cultivar uses parent plant name with a common name in quotes
EX: Ceanothus (italicized) “blue jeans”
Ceanothus “frosty blue” - Plant is then placed in a “cultivar group” based on: growth habit, color, any structure
Kingdom Protista
- eukaryotes that don’t fit into other kingdoms
- Polyphyletic group:
• single- and multicellular, colonial, filamentous
• autotrophs and heterotrophs
most have flagella
Phylum Chlorophyta
– green algae
- presumed ancestor of plants
- variations: single-celled, filamentous, colonial
- store food as starches
- chlorophyll a and b
Chlamydomonas
- 1 billion yr. old genus
- freshwater plankton
- really small
- cup-shaped chloroplast
- one large pyrenoid synthesizes & stores starch
- two flagella
- eyespot
Chlamydomonas reproduction
- adults are haploid (N)(one copy of each chromosome)
- asexual reproduction: mitosis
- sexual reproduction:
1. pairs fuse into 2N zygote (fertilization)
2. zygote grows into zygospore
3. zygospore meiosis → 4 genetically unique haploid zoospores (i.e., swimming spores)
4. zoospores grow into adults-
Ulothrix
- freshwater filamentous algae, grows on twigs, rocks, debris
- holdfast = attachment cell; cannot divide
- all other cells identical and capable of division growth via mitosis
Ulothrix asexual reproduction
- filament cells are haploid
- filament cell mitosis → zoospores
- zoospores swim around and settle
- create holdfast and new filament cells by mitosis
Ulothrix sexual reproduction
- swimming zoospores act as gametes - fuse to form zygote
- zygote settles
- zygote undergoes meiosis → 4 genetically unique zoospores
- zoospores swim away and settle
- mitosis leads to new filament
Spirogyra
- freshwater filamentous algae
- spiral chloroplasts with pyrenoids along length
- Reproduction: adults are haploid
- Asexual reproduction via fragmentation
- Sexual reproduction via conjugation
Spirogyra sexual reproduction: conjugation
- Adjacent filaments connect via conjugation tubes
- DNA-containing protoplasts migrate from one strand to another
motile protoplast = male
non-motile protoplast = female - Fusion of protoplasts → zygote
- Zygote undergoes meiosis → 4 genetically unique daughters
- 3 disintegrate, 1 lives on; new filament via mitosis
Oedogonium
- Freshwater filamentous algae
- Epiphyte on plants and other algae
- Holdfast for attachment
- Net-like chloroplasts, pyrenoids throughout
Oedogonium asexual reproduction
- adult is haploid
- asexual reproduction via fragmentation or zoospore
1. rounded filament tip produces zoospore
2. zoospore swims and settles
3. new filament produced by mitosis
Oedogonium sexual reproduction
- gametangium produces either 2 sperm (if antheridium) or 1 egg (if oogonium)
- sperm swim to egg (chemical attraction) and fuse
- zygote undergoes meiosis → 4 genetically unique zoospores created
- zoospores swim away and settle
- new filament created via mitosis
Volvox
colonial; daughter colonies form inside
Ulva
- aka sea lettuce
- leaf-like blades
- may be haploid or diploid
Acetabularia
- aka mermaid’s wine glass
- 2” long cells
- isogamous
fucoxanthin
- a brownish xanthophyll
Class Xanthophyceae
- yellow-green algae
- asexual reproduction → aplanospores (non-motile spores); sexual reproduction is rare
Class Chrysophyceae
- golden-brown algae
- fresh-water plankton
- may form statospores (resting spores)
Class Bacillariophyceae
- diatoms
- freshwater and marine, bark, soil
- some resistant to desiccation
- up to 48 years (via statospore)
- use chlorophylls a, c1, c2, fucoxanthin
- encased in silica glass; one half fits into the other
Class Bacillariophyceae Asexual reproduction
- Asexual reproductions via “shrinking division”:
1. Diploid contents undergo mitosis
2. Two halves of cell separate
3. New half is created, fitting inside original
4. Silica glass shrinks every time → daughter cells get progressively smaller
5. Shrinking eventually leads to sexual reproduction
Class Bacillariophyceae
Sexual reproduction
Sexual reproduction follows “shrinking division”
- Meiosis → 4 genetically unique haploid gametes
- Gametes fuse
- Zygote becomes auxospore (“auxo-” = grow, enlarge) → restores cell size
Class Phaeophyceae
- brown algae
- All multicellular; none unicellular or colonial
- Many are seaweeds
- Thallus (body) is plant-ish
- stipe is stem-ish
- holdfast is root-ish
- blade is leaf-ish also have gas bladder for
floatation - no true vascular tissue
Class Phaeophyceae sexual reproduction
- Adults are diploid
- May have separate male and
female thalli or both sexes may be present on same thallus - Gametes produced via meiosis
Fucus sexual reproduction
- adults create either male or female receptacles (swollen fertile areas at blade ends)
- develop into conceptacles (cavities) with gametangia
- gametangia produce egg or sperm
a. males: antheridia make 64 sperm via meiosis and 4x mitosis
b. females: oogonia create 8 eggs by meiosis followed by mitosis
- gametes released into water → fertilization
- zygote grows into diploid male or female thallus
red algae
- some unicellular, most are filamentous
- fused filaments look like blades
- more branched than typical seaweeds
- phycobilins create red color mask chlorophyll a and b
- food reserves as floridean starch
Red algae sexual reproduction
1a. haploid males have spermatangia that produce spermatia (non-motile male gametes) via mitosis
1b. haploid females produce carpogonia (specialized female gametangia)
antenna-like trichogyne with egg nucleus at base
2. current carries spermatia against trichogyne where they attach
3. walls of each break down and nuclei of spermatia and carpogonia fuse (fertilization) → zygote
4. on female gametophyte, diploid zygote develops as part of a cystocarp
5. zygote creates carposporangia that produce carpospores via mitosis
6. released carpospores anchor, undergo mitosis to grow into tetrasporophyte thalli
7. tetrasporophytes create tetrasporangia that produce 4 tetraspores via meiosis
8. tetraspores grow into male or female gametophyte thalli
Phylum Euglenophyta
- Unicellular, flagellated
- Not obligate photosynthesizers
- energy from photosynthesis or by consuming other organisms
oral groove for ingestion of food - Red eyespot for perceiving light exhibit positive phototaxis
- Reproduction: asexual via mitosis
(split down middle); sexual is unknown
Phylum Dinophyta
- unicellular
- two flagella: 1 steers, 1 spins
- armor-plated
- ~ 55% are photosynthetic
- xanthophyll plus chlorophyll a and c2
- reproduction: asexual via mitosis, sexual: unknown details
Phylum Cryptophyta
- unicellular and flagellated
- marine or freshwater
- single bi-lobed chloroplast
- store food as starch
- predators & photosynthesizers
- reproduction:asexual via mitosis, sexual is unknown
what organisms are the the Kingdom Protista phylum Chlorophyta?
- Chlamydomonas
- Ulothrix
- Spirogyra
- Oedogonium
- Volvox
- Ulva
- Acetabularia
what organisms are the the Kingdom Protista phylum Chromophyta?
- Class Xanthophyceae
- Class Chrysophyceae
- Class Bacillariophyceae
- Class Phaeophyceae
- ## Fucus
what organisms are the the Kingdom Protista phylum Rhodophyta?
- red algae
Fungi
- Non-photosynthetic
- Filamentous or unicellular
- heterotrophs
- Absorb nutrients in solution
- more like animals than plants
What are the three life stages for fungi
- saprobe: nutrients from decaying organics
- parasite: harms a living host
- mutualistic symbiont: both benefit
Chytrids
- primitive; mostly unicellular,
- aquatic
- parasites and saprobes attach to food via small structures called rhizoids
Chytrids reproduction
- no ploidy pattern
- many asexual with motile zoospores
- some have sexual reproduction:
- fusion of motile gametes or non-motile cells
- followed by meiosis
- motile spores suggest evolution from protozoans
What phylum is chytrids apart of?
Phylum Chytridiomycota
Coenocytic fungi
- refers to structural/functional linkage via coenocytic hyphae
- hypha = filamentous cell
- mycelium = vegetative body
mycelia asexual reproduction
- haploid
1. mycelium creates vertical hypha called
sporangiophore- each sporangiophore grows a sporangium
- sporangium creates spores via mitosis
- released spores germinate, grow into horizontal mycelia
mycelia sexual reproduction
- two different hyphal strains (+ or -)
- not male and female, just “different”- opposite strains grow progametangia towards each other
- at contact, cross walls isolate tips that grow into gametangia
- gametangia merge to create a 2N zygote
- zygote grows into zygosporangium
- meiosis produces spores within sporangia (atop sporangiophores)
- spores distributed by wind or forcibly expelled (up to 8 feet) to germinate into new mycelia
What phylum are mycelia and Coenocytic fungi apart of?
phylum Zygomycota
What phylum is chytrids apart of?
Phylum Chytridiomycota
Coenocytic fungi
- refers to structural/functional linkage via coenocytic hyphae
- hypha = filamentous cell
- mycelium = vegetative body
mycelia asexual reproduction
- haploid
1. mycelium creates vertical hypha called
sporangiophore- each sporangiophore grows a sporangium
- sporangium creates spores via mitosis
- released spores germinate, grow into horizontal mycelia
mycelia sexual reproduction
- two different hyphal strains (+ or -)
- not male and female, just “different”- opposite strains grow progametangia towards each other
- at contact, cross walls isolate tips that grow into gametangia
- gametangia merge to create a 2N zygote
- zygote grows into zygosporangium
- meiosis produces spores within sporangia (atop sporangiophores)
- spores distributed by wind or forcibly expelled (up to 8 feet) to germinate into new mycelia
What phylum are mycelia and Coenocytic fungi apart of?
phylum Zygomycota
Sac fungi
- refers to shape of spore container
- unicellular, multicellular, colonial
- separate hyphae have cross walls with pores
Sac fungi asexual reproduction
Reproduction: asexual
- multicellular sac fungi produce conidia (spores produced via mitosis rather than meiosis)
- yeasts (only unicellular sac fungi) undergo budding
Sac fungi asexual reproduction
- closely-associated hyphae connect ( male- antheridium, female- ascogonium)
- nuclei from antheridium migrate to ascogonium and make dikaryotic cells
- dikaryotic cells grow ascogenous hyphae that grow into large ascoma
- top layer of ascoma matures into hymenium with row of fingerlike asci
- ascogenous hyphae in hymenium create hooked crozier cells
- nuclei in crozier cells undergo mitosis
- walls develop, dividing crozier cell into 3 cells
- nuclei in the third cell fuse, creating zygote
- Zygote does meiosis and mitosis
- ascospores are released from asci and germinate into new haploid hyphae
Why is phylum ascomycota important to humans?
- plant diseases
- food
What phylum is sac fungi apart of?
Phylum Ascomycota
club fungi
- mushrooms, toadstools, puffballs, shelf fungi, rusts, smuts
- decomposers or parasites
What are the tree sections of club fungi
- cap: top; spores produced in gills on under side
- stipe: a stem-like structure
- annulus: scar tissue on stipe from before cap was opened
Cub fungi asexual reproduction
- asexual repro infrequent
- typically produce conidia
- some undergo budding or fragmentation
Cub fungi sexual reproduction (decomposers)
- compatible monokaryotic mycelia fuse to create dikaryotic mycelia (1 with 3 and 2 with 4)
- dikaryotic mycelia grow into mass called a button
- button develops into basidioma (“mushroom”)
- basidia develop in gills under cap
5. nuclei in basidia cells fuse (2n) creating zygote
6. zygote does meiosis, creating basidiospores
7. basidiospores are wind distributed
8. spores germinate into monokaryotic hyphae
Club fungi sexual reproduction (parasites)
- mycelia attach to barberry leaves and grow into spermagonia
- spermagonia develop either spermatia (male) or receptive hyphae (female-ish)
- spermatia and receptive hyphae of compatible mating types fuse to create dikaryotic (n+n) cell
- dikaryotic cell grows into aecium which creates aeciospores by mitosis
- spores attach to wheat, develop mycelia
6a. mycelia create uredinia that create urediniospores
→ spread infection on wheat
6b. mycelia create telia which create teliospores- in teliospores, nuclei fuse into zygote, which overwinters
- diploid zygote creates basidiospores via meiosis
- basidiospores germinate, grow into mycelia on barberry
Why is phylum Basidiomycota important to humans
- food
- crop destruction by rusts and smuts
What phylum is club fungi apart of?
phylum Basidiomycota
What types of fungi go into Phylum Deuteromycota
- fungi that they can’t classify into a specific phylum because they don’t know a lot about them
What synapomorphy is in phylum Deuteromycota?
no known sexual reproduction
Why is phylum Deuteromycota important to humans?
- medicine
- food
- plant and animal infections
- Diseases
Lichens
- fungus
- photosynthetic alga
- cyanobacterium
- Attach to rocks, plants, logs; most are not parasitic
What are the 3 growth habits of lichens
crustose: crusty, low-growing, often bright
2. foliose: leaf-like appearance
3. fruticose: tiny shrub-like bodies
Thallus anatomy
- Upper cortex: protects against elements
- Algal layer: photosynthetic section, algae exist between hyphae
- Medulla: loosely packed hyphae, storage layer
- Lower cortex: not always present creates rhizines that anchor the lichen
Lichens asexual Reproduction
via soredia - powdery granules of fungal & algal cells
-via fragmentation due to decay
distributed by rain, wind, animals
Lichens sexual Reproduction
similar to Ascomycota
