Lecture 20- Exploring Protist Diversity

Question 1

why are protists an example of a paraphyletic group?

Answer 1

because they do not contain all descendants from their ancestor taxa

Question 2

eukaryotic cells are more complex than prokaryotic cells. what are the 4 eukaryotic supergroups?

Answer 2

excavata
SAR (stramenopile, alveolate, rhizaria)
archaeplastida
unikonta

Question 3

how is the excavata clade different from the other clades?

Answer 3

have an excavated feeding groove

Question 4

a phylum inside the excavata are the euglenozoans, what are they? what do they consist of?

Answer 4

dependent on something to survive
have a flagella

Question 5

euglenids are types of protists that are in the euglenozoans, what are characteristics of them?

Answer 5

unicellular
freshwater organism
contractile vacuole
mixotrophic

Question 6

what would happen if the organism didn’t have a contractile vacuole?

Answer 6

the cell would explode due to osmosis

Question 7

what is mixotrophy?

Answer 7

organisms can be autotrophic when light is available or when light isn’t available, heterotrophic

Question 8

what makes the SAR clade different from the other clades?

Answer 8

defined by DNA similarities

Question 9

what are four phylums in the SAR clade?

Answer 9

diatoms
golden algae
brown algae
dinoflagellates

Question 10

what is unique about diatoms?

Answer 10

make up sand
unicellular algae

Question 11

what is unique about golden algae?

Answer 11

they are basically just colonies of unicellular organisms
have a very simple structure

Question 12

what is unique about brown algae?

Answer 12

multicellular

Question 13

why are algae and plants analogous?

Answer 13

algae have:
blades (like a leaf)
stipe (like a stem)
holdfast (like roots)

Question 14

how does the SAR/ brown algae lifecycle work?

Answer 14

fertilization (sperm and egg)
zygote (2n)
sporophyte (2n)
within sporangia there are spores
spores undergo meiosis
meiosis forms multicellular female gametophytes (n) and multicellular male gametophytes (n)

Question 15

what is unique about dinoflagellates?

Answer 15

toxins of dinoflagellates results in a red tide which kills sponges and fish

Question 16

how are archaeplastida different from other clades?

Answer 16

diverse habitats
live on land, freshwater and ocean
closest relatives of land plants

Question 17

what do phyla archaeplastida consist of? (2)

Answer 17

red algae
green algae (charophytes & chlorophytes)

Question 18

in the archaeplastida an example are chlamydomonas, why are they model organisms?

Answer 18

unicellular
small
reproduce easily
simple organization

Question 19

what is unique about charophytes?

Answer 19

they use isogamy which is when gametes of different mating types (+/-) are physically identical

Question 20

what is unique about charophytes life cycle?

Answer 20

there is no alteration of generations, the main form is (n)

Question 21

what is unique about charophytes life cycle?

Answer 21

there is no alternation of generations, the main form is (n)

Question 22

what is unique about red algae? (3)

Answer 22

mostly multicellular
no flagellate
nori for sushi

Question 23

what are the 3 things the algal cell structure consists of?

Answer 23

cell wall
vacuole
pyrenoids (only in algae, are within chloroplasts)