Lab #3: Microalgae

Question 1

Euglenoids supergroup

Answer 1

Supergroup Discoba

Question 2

Euglenoid Characters

Answer 2

Cell: Eukaryotic but chromosomes remain condensed throughout most
of the cell cycle

Cell covering: No cell wall, has a “pellicle” inside of the plasmalemma

Flagella: One or usually two flagella, often with only one long enough to
emerge from the cell

Chloroplast: Double membrane with one layer of chloroplast ER, thylakoids
usually in stacks of three, primary pigment is chlorophyll a,
accessory pigments are chlorophyll b, ß carotene, xanthophylls

Food storage: Paramylon (a β- 1,3 glucose polymer)

Level of organization: unicellular

Reproduction: Asexual only. Sexual reproduction not confirmed

Habitat: Mostly fresh water, some marine species

Question 3

Euglena

Answer 3

2 Flagella on anterior of cell
only 1 extends out of resoivoir
Stigma (eyespot)
Spiral swimming
Chromosomes permanently condensed

Question 4

Phacus

Answer 4

oval in shape
movement like leaves falling from tree

Question 5

Trachelomonas

Answer 5

Surrounded by protective extracellular matrix called a lorica

movement by long flagellum that extends through lorica

Question 6

Haptophytes supergroup

Answer 6

Supergroup Haptophyta

Question 7

Haptophytes Characteristics

Answer 7

Cell : eukaryotic
Cell covering: Many cells have scales made of CaCO3
Flagella: Two smooth flagella
Chloroplast: Usually two discoid chloroplasts per cell. Double membrane with
two added layers of chloroplast ER, thylakoids in stacks of three,
primary pigment is chlorophyll a, accessory pigments are
chlorophyll c, ß-carotene, xanthophylls (especially fucoxanthin,
diadinoxanthin and diatoxanthin)
Food storage: Chrysolaminaran
Level of Organization: unicellular
Reproduction: Asexual by cell division, sexual reproduction is isogamous
Habitat: primarily marine

Question 8

Dinoflagellate Supergroup

Answer 8

Alveolata

Question 9

Dinoflagellate characteristics

Answer 9

Cell: dikaryotic covering
Cell covering: Usually, a cell wall of cellulose laid down as thecal plates, located
under the cell membrane
Flagella: Usually with two flagella having independent beating patterns
Chloroplast: Double membrane + one layer of chloroplast ER, thylakoids in
stacks of three, primary pigment is chlorophyll a, accessory
pigments are chlorophyll c, ß-carotene, xanthophylls (especially
peridinin and neoperidinin)
Food storage: starch
Level of organization: unicellular
Reproduction: Asexual cell division (sexual reproduction is zygotic)
Habitat: Aquatic, some are fresh water but many marine, important
constituents of marine phytoplankton. Some occur as symbionts
in shallow-water marine corals

Question 10

Clingulum

Answer 10

equatorial groove holds transverse flagellum

Question 11

Suculus

Answer 11

holds the longitudinal or posterior flagellum

Question 12

Epicone

Answer 12

The anterior half of the organism

Question 13

Hypocone

Answer 13

The posterior half

Question 14

Epitheca

Answer 14

Anterior half of armoured dinoflagellates

Question 15

Hypotheca

Answer 15

Posterior half of armoured dinoflagellates

Question 16

Diatom Supergroup

Answer 16

Stramenopila

Question 17

Diatom Characters

Answer 17

Cell: eukaryotic
Cell covering: A cell wall made of two silica valves (frustules)
Flagella: Unflagellated (pennate) or sperm with one flagellum (centric)
(heterokont, with loss of one flagellum)
Chloroplast: Double membrane with two added layers of chloroplast ER,
thylakoids in stacks of three, primary pigment is chlorophyll a,
accessory pigments are chlorophyll c, ß-carotene, xanthophylls
(especially fucoxanthin, diadinoxanthin and diatoxanthin)
Food storage: Lipids, leucosin, chrysolaminaran
Level of organization: Form is unicellular, colonial, filamentous or chain-forming
Reproduction: Asexual by cell division, sexual reproduction is oogamous (centric
diatoms) & isogamous (pennate diatoms); gametic meiosis
Habitat: fresh and marine water

Question 18

Centric diatoms

Answer 18

Have radial symmetry when viewed in valve view

Question 19

Pennate diatoms

Answer 19

Have bilateral symmetry in valve view

Question 20

Melosira

Answer 20

centric genus forms chains
adhere to each other via valve side of cell