crysophytes

Question 1

what are the golden phytoflagellates

Answer 1

chrysophytes

Question 2

what is the range of morphologies seen in chrysophytes

Answer 2

they can be unicellular, colonial, naked, loricated, or scaly (tiny spines made out of glass for outer cell wall)

Question 3

what are the photosynthetic pigments in chrysophytes

Answer 3

• xanthophyll fucoxanthin (gives the goldish green color)
• chlorophyll a and c (which they share with diatoms)

Question 4

when chrysophytes photosynthesize what product do they make

Answer 4

they don’ make starch instead they store excess as chrysolaminaran (just like diatoms)

Question 5

what environment are crysophytes found in

Answer 5

freshwater algae found in cold and unproductive lakes - often blooming in spring after the ice out

Question 6

chrysophyte blooms tend to give what odour

Answer 6

fishy smell

Question 7

are chrysophytes heterotrophic, phototrophic, or mixotrophic

Answer 7

they are mixotrophic (naked ones are involved in phagotrophy and the scaly ones are not involved in phagotrophy they absorb carbon from the environment through osmosis)

Question 8

naked chryosphytes resemble what

Answer 8

gametes of diatoms

Question 9

describe the flagella of chrysophytes

Answer 9

2 - biflagellate
- the flagella are of unequal length (heterokontic) - one goes straight up and the other goes 90 degrees to it
- the flagella are anchored by rhizoplast so less likely to eject flagella in stress
- the flagella are mastigonemized (have hair on them)

Question 10

What features can you see on naked chrysophytes

Answer 10

• they are eukaryotic
• have nucleus, plastids, vacuoles, eyespot
• heterokontic flagella anchored by rhizoplast

Question 11

describe the stress response of chrysophytes

Answer 11

they have these organelles called mucocysts which excrete a mucilage in response to environmental stressors

Question 12

how do chrysophytes do phagotrophy

Answer 12

the naked chrysophytes eat bacteria, they have mastigonemized flagellum which they use to capture bacteria and ingest it at the base of the flagella

Question 13

Describe the reproduction of chrysophytes

Answer 13

• they have isogamous sexual reproduction
• in general they are haploid but they have a diploid resting structure called stomatocyst in a loricated chrysophyte

Question 14

What are the two types of chrysophytes

Answer 14

the naked ones (mixotrophs + phagotrophy)), and the scaly ones (mixotrophs with no phagotrophy - they do osmosis)

Question 15

What do are the scales of the scaly chrysophytes made up of

Answer 15

silica

Question 16

What is the other term for the scaly chrysophytes

Answer 16

synurophytes

Question 17

Why are the scaly crysophytes not able to do phagotrophy

Answer 17

because of their scales

Question 18

Describe the reproduction of synurophycean

Answer 18

• synurophycean = scaly crysophytes
• the female gamete associated with the colony is fertilized by male gamete to produce a diploid stomatocyst - the stomatocyst then remains part of the maternal colony

Question 19

what is the resting structure of the chrysophytes and the synurophytes called

Answer 19

stomatocysts

Question 20

what are the overall points of chrysophytes and synurophytes

Answer 20

• they are freshwater biflagellates that bloom a lot in the spring
• are isogamous species
• resting structure is stomatocysts
• thought to be ancestral link to diatoms

Question 21

what algae are thought to be the ancestral link to diatoms

Answer 21

chrysophytes and synurophytes