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Home , Marimo, Phragmoplast, Phycoplast

Marine Midterm 2014 Name:______

Compare and Contrast the following items (20pts):

1) vs gamete

Spore: unicellular, must settle & grow, product of (Mt) or (Me)

Gamete: unicellular, must fuse or die, product of mitosis(Mt) or meiosis (Me)

2) monoecious vs dioecious

Dioecious- having the male & female reproductive structure borne on separate individual ; said of the species -two houses

Monoecious- having the male & female reproductive structure borne on the same individual plants -one house

3) vs. Phycoplast: parallel to dividing plane -rare in

Phragmoplast: double microtubules perpendicular to dividing plane-common in algae & land plants

4) haplontic vs diplontic

Haplontic: 1N thallus, the zygote is the only diploid stage

Diplontic: 2N thallus, the gametes are the only haploid stage

5) parenchymatous vs. coenocytic thallus construction

Parenchyma – undifferentiated, isodiometric cells generated by a Cells division in any plane , not filamentous

Coenocytic – thallus made up of filaments, multi-nucleate, lacking crosswalls, siphonous

1 Marine Botany Midterm 2014 Name:______

Match with the correct Division: , Heterokontophyta, both, or neither (12 points) a. Plantae __Chloro______

b. A _Both______

c. ______Neither______

d. Phycobilins _____Neither______

e. Amylose ___Chloro______

f. Thylakoids in stacks of 2-6 ______Chloro___

g. Bacteria ______Neither______

h. Flagella ____Both______

i. Haplontic life history _____Chloro______

j. 2 endosymobiotic event ____Hetero______

k. Chromalvaeolates ______Hetero______

l. Mannitol______Hetero______

Match the following Classes or Orders to the appropriate characteristic, term, or genus. Each term will be used only once. (10 points)

Cladophorales ___C_____ A. parenchymatous thallus Ulotricales ___J_____ B. clockwise basal body orientation _____B____ C. marimo balls ____G____ D. modern representative of ancestral green (most primitive)

Trebouxiophyceae ____F____ E. one nucleus & radial symmetry Dasycladales __E______F. e.g. Prasiola Caulerpales ___I_____ G. broad band , closely related to land plants Fucales _____H___ H. monoecious or dioecious Prasinophyceae ____D____ I. group contains coenocytic mass-spawners Ulvales ______A____ J. Codiolum phase

2 Marine Botany Midterm 2014 Name:______

Define the terms below (20pts):

1) algae: convenience term encompassing various distinctly related groups of aquatic photsynthetic eukaryoes polyphyletic group containing, cyanobacteria, , dinoflgellates, red, green and

2) physode: special vesicles in the cytoplasm of that store tannins

3) hypnozygote: thick walled resting stage of the 2n zygote in Chlamdymonous sexual life history when there is not enough light or nitrogen

4) saxicolous: Growing on rock

5) plurilocular sporangia: structure where are formed that is divided into many small chambers :one spore/gamete per chamber

6) functional anisogamy: Gametes look the same but act differently in heterokontophyta, female gamete release phermones and males swim towards females

7) : -a large float containing gas found in heterokontophyta -provide buoyancy to lift the blades toward the surface, allowing them to receive more sunlight for Ps - can hold O2, CO2, CO

8) holocarpic :

- Entire thallus turns into gametes

9) ectocarpene: pheromone released by female gamete in ectocarpales

10) alginic acid- found in cell walls of heterokontophyta, surrounds the microfibrills,allows cell walls to be elastic,flexible, and to osmoregulate

3 Marine Botany Midterm 2014 Name:______

Create a dichotomous key to separate the following genera: Fucus, Codium, Silvetia, Chlamydomonas, . You may not use taxonomic names of divisions, classes, or orders, but should instead use characteristics of the divisions, classes, orders or genera (10 pts)

Codium, Cladophora, Clamydomonas- Chl B, lutien,neoxanthin, (Amylose, Amylopectin), 2 membranes, thylakoids stacks 2-6, flagella-isokont, variable #, haplontic

Codium & Cladophora- counterclockwise basal bodies,cruciate microtubule roots, , closed spindle,furrowing,phragmoplast

Codium- ceonocytic, siphonous, biflagellate, anisogamous,, no division of cytoplasm with cell walls, clotting compounds, diplontic, utricles, gametangium, invasive on the east coast

Cladophora-large, multinucleate cells divided by crosswalls,isomorphic alteration of generations, reticulate or multiple discoid ,can form marimo balls,branched filamentous,

Chlamydomonas-haplontic,unicells,hypnozygote, palmenoid stage,cupshaped ,orange eyespot,mapped genome,cruciate microtubules,clockwise basal bodies,cell wall,closed spindle,phycoplast, furrowing

Fucus, Silvetia- Chl C,fucoxanthin, sugars (Laminarian,Chrysolaminarian,Mannitol), 4 membranes, thylakoids stacks of 3, - one is hairy, diplontic, oogamous, parenchymatous, apical growth, receptical, conceptical,

Fucus- midrib, 8 eggs per oogonium Silvetia- playdough stipe, 2 eggs per oogonium

Please label the components (A through E) of the P-I curve below (7pts):

A_Photosynthetic Rate (y axis)

B Compenstion point (= respiration) E C initial slope = photsynthetic A efficiency, theta

C D light intensity or irradiance (x axis)

E __photoinhibition______

B D

What aspect of the light reactions in photosynthesis might cause a higher value for P-max? More PSU 4 Marine Botany Midterm 2014 Name:______

Draw a life history diagram as indicated below. Please label ploidy (N or 2N) of all stages, when meiosis and mitosis occur, and sketch (very generally) the algae look like. (20 pts)

1) Circle the order you are illustrating: Either Ulotrichales or Fucales What type of life history does it exhibit?___Haplontic or Diplontic______

Ulotricales- haplontic 1N thallus (1N ) mitosis1N gametesfuse2N zygote meiosis occurs in zygote1N codiolumLife Cyc stagele of th1Ne U sporeslotrich (zoospores)ales 1N thallus Haplontic e.g. Ulothrix

syngamy

1N gametes 2N zygote

meiosis occurs in zygote

1N 1N codiolum stage

1N zoospores Fucales- diplontic- oogamous 2N thallus meiosis1N gametes(one flagellated, and one not )fuse2N zygote grows 2N thallus

2) Isomorphic Alternation of Generations: gametophyte & loof the same What order exhibits this life history?___Ulvales

1N gametophytemitosis1N gametes (2 flagella look the same)fuse2Nzygote2N sporophytemeiosis1N zoospores ( four flagella)grow into 1N gametophyte

5 Marine Botany Midterm 2014 Name:______

Short Answer (25 pts): 1. What determines the upper and lower limits of algae in the intertidal? Upper limit- abiotic factors- tide, temperature, light intensity, sand & physiological tolerance of the species Lower limit- biotic factors- herbivory, competition

2. Explain how Luchenco & Cubit changed the way people thought about heteromorphic life histories of certain marine algae as adaptations to variation in herbivory?

Heteromorphic life histories was thought to be due to seasonal conditions, but proved that they were driven by herbivory. When herbivores were excluded upright morphs grew no matter the season.

3. In the paper by Sousa, Disturbance in marine boulder fields: the non equilibrium maintenance of species diversity. Which size boulders had the highest diversity? How did he determine this?

Medium sized boulder highest diversity Surveyed small, medium and large boulder to count number of species Secured small & medium boulder so that they wouldn’t roll, look at how diversity changed to factor out size of boulder from disturbance level

4. Explain the phenology of sexual reproduction by on Caribbean Coral Reefs as described by Clifton and Clifton.

Holocarpic reproduction- seasonallybefore the wet season begins-gamete release is synchronous and species and gender specific, different genuses release at similar times, while similar species release gametes at different times

5. What happens during a secondary endosymbiotic event? Heterotrophic eukaryote eats photosynthetic eukaryote Nucleus from photosynthetic eukaryote is lost Results in photosynthetic eukaryote. Chloroplast has 4 membranes.

6 Marine Botany Midterm 2014 Name:______

Short essay: (20 pts) 1) Light is one of the most important factors affecting photosynthetic organisms and how light travels through water is important in algal growth. Describe in detail the effects of light on algal growth. Include in your answer a description of light attenuation (what is it, how do different wavelengths respond, and how do algae deal with it). Attenuate: to lessen in severity, intensity, or amount At ~ 100 m even in clearest water, only 1% of surface radiance makes it through Light attenuation is due to: Absorption (red-long wave length, low-energy wavelengths absorbed first, by water itself.) Scattering (violet-high energy, short wave lengths scatter due to water molecules and particulates) Across species: Different Divisions have different pigments, allow species to gather different wavelengths of light Within species Irradiance not spectral quality 1) produce more accessory pigments-change ratio of accessory pigments 2) produce more photosynthetic pigments- Change size of PSUs-antennae + reaction center (larger is more efficient at low light levels) 3) morphology matters- thicker fronds, arrangement of chloroplasts, More surface to capture light, crustose algae should do best in dim , less self shading, Thicker thalli should have a growth disadvantage in dim habitats, also self-shading

2) The rocky intertidal is a rough place to be an alga and yet so many algae are found there. Please describe the challenges that algae in the rocky intertidal face and adaptations these algae have to overcome such harsh conditions. Challenges: Abiotic: Light, Temperature, Salinity, Nutrients, Water Motion, TIDES, Sand Burial Biotic: Herbivory, Competition,Epiphytism Adaptations: - Wicked holdfasts for attachment - Morphology that minimizes drag, shear stress - Tolerant of high temps (H2O temperature typically 10-17 degrees C along Central Coast; in tide pools, up to 30 degrees C) - Desiccation tolerance (some algae can survive 60-90% water loss), some require low tide for survival - Synchrony in gamete release (e.g. intertidal Fucoids, like Silvetia compressa) - Photoprotective pigments

7 Marine Botany Midterm 2014 Name:______

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