lecture 10 (other stramenopiles)

Question 1

describe the general structure of an Ochromonas cell, and what group its in

Answer 1

a Chrysophycean, one or more emergent flagella (heterokont), looks similar to euglenoids

Question 2

describe the vegetative state of dinobryon

Answer 2

tree-like colonial arrangement in a shared lorica

Question 3

chrysophytes produce a characteristic resting stage/cyst. what does it look like and what is it called?

Answer 3

it is called a stomatocyst
this is silica walled, with an unsilicified region at the apex which forms a pore, plugged with polysaccharides with an elevated margin/collar. form from sexual or asexual reproduction

Question 4

what are two genera of marine raphidophyceans that are well known for producing harmful blooms?

Answer 4

chattonella (high amounts of reactive oxygen species and hydrogen peroxide, toxic fatty acids)
heterosigma

Question 5

what accessory pigment is missing in xanthophyceans that is present in other stramenopiles?

Answer 5

fucoxanthin

Question 6

some species of xanthophyceans are found in siphonaceaous coenocytes
describe the morphology

Answer 6

eg. vaucheria, can form large mats of filaments

Question 7

describe tribonema (a xanthophycean)

Answer 7

unbranched filament with single row of cells, cell wall composed of two rigid overlapping halves that look like the letter H