Algae

Question 1

Properties of an algae.

Answer 1

• Eukaryotic
• Chloroplast
• Photosynthesis
• Polyphetic
• Unicellular, colonial, filamentous, complex multicellular
• Microscopic and macroscopic

Question 2

Describe microscopic algae.

Answer 2

unicellular, colonial, small as 0.8µm, some are motile

Question 3

Describe macroscopic algae.

Answer 3

multicellular → filamentous and complex, brown algae can grow 0.5 metres per day

Question 4

What habitats are algae found in?

Answer 4

Freshwater. Marine. On/in rocks/ Soils. Snow/ice. Hot springs

Question 5

What is meant by symbiotic?

Answer 5

Live inside or alongside other organisms

Question 6

How do algae help oxygenate the earth?

Answer 6

Photosynthesis. Algae fixed carbon and released oxygen.

Question 7

What is algaes commone ancestor?

Answer 7

Doesn’t have. Has multiple origins

Question 8

What algae as are in the group archaeplastida?

Answer 8

Red algae. Green Algae. Land plants.

Question 9

What group are Dinoflagellates?

Answer 9

Alveolates

Question 10

What group are Coccolithophores?

Answer 10

Unclassified

Question 11

What algae as are in the group Stramenopiles?

Answer 11

Diatoms and brown algae

Question 12

How are algae endosymbionts?

Answer 12

Chloroplast comes from a prokaryotic cyanobacterial source

Question 13

How did algae gain a chloroplast?

Answer 13

Early eukaryote engulfed a aerobic heterotrophic prokaryote → form mitochondria
Further engulfed a prokaryotic cyanobacteria which had the ability of photosynthesis
This formed a chloroplast

Question 14

How was there endosymbiotic gene transfer with an alae?

Answer 14

Genes from cyanobacteria would transfer to the nuclear genome of the algae

Question 15

How do algae show multiple endosymbiotic events?

Answer 15

They are primary, secondary and tertiary endosymbionts.

Question 16

What algae to primary endosymbiosis produce?

Answer 16

green algae, glaucophytes and red algae

Question 17

Describe the secondary endosymbiosis of algae.

Answer 17

red algae was engulfed by a series of other non photosynthetic heterotrophs

Question 18

What are the features of green algae?

Answer 18

• Primary endosymbionts
• Near oblique autotrophs
• Symmetrical flagella

Question 19

What is model green algae?

Answer 19

Chlamydomonas reinhardtii - to study photosynthesis, genetics and phototaxis

Question 20

What is the cellular structure of green algae?

Answer 20

• Cell wall and plasma membrane
• Chloroplast
• Pyrenoid → where they put RuBisCO
• Mitochondria
• Nucleus
• Flagella
• Vacuole → buoyancy

Question 21

What is the life cycle of green algae?

Answer 21

• Mostly in haploid reproduction
• Under stress conditions goes through sexual
• Has mating types - need to opposite types to fuse and for a zygote

Question 22

How can green algae be structurally diverse?

Answer 22

Can be filamentous. Can be multicellular. Form colonial structures.

Question 23

What pigment does red algae contain?

Answer 23

Pigment phycorythrin (red pigment)

Question 24

What is the purpose of pigment phycorythrin?

Answer 24

Absorbs light efficiently in the green and blue.

Question 25

What does coralline algae doe?

Answer 25

Calcify their fronts - calcium carbonate deposit in cell walls. Produce foundation of coral reefs.

Question 26

What are the uses of red algae?

Answer 26

Wrap sushi. Produce valuable polymers (agar and agarose)

Question 27

What are the features of coccolithophores?

Answer 27

Unicellular calcifying marine algae. Secondary endosymbionts. Unclassified.

Question 28

How do coccolithophores make internal structures?

Answer 28

Calcium carbonate structures. Then put the shell on the surface.

Question 29

Why do coccolithphore calcify?

Answer 29

Accelerated photosynthesis. Photodamage protection - dissipates light? Armour against attack. Ballast to modify position in water column

Question 30

Why are coccolithophores important in geology?

Answer 30

Turn the ocean milky colour. Deposit chalk - white cliffs of Dover.

Question 31

What are the main functions of diatoms?

Answer 31

- Secondary endosymbiont - Saltwater - Account for 20% of CO2 fixation

Question 32

What are the main structures of diatoms?

Answer 32

- Two dissimilar flagella (heterokonts) - Unicellular - Silica cell walls called frustrules

Question 33

What is the role of frustrules in diatoms?

Answer 33

Have pores to allow exchange of materials. Protect from grazing and infection.

Question 34

What are the two main groups of diatom>

Answer 34

Centrics - radial. | Pennates - bilateral/

Question 35

What is a centric diatom?

Answer 35

- Each daughter cell receives half of frustrule - New frustule formed with parental half - Results in decline in size - Get to the point where its infertile - They then go through meiosis and form a gamete

Question 36

What are the main features of brown algae?

Answer 36

- Stramenopile - Multicellular - No vascular system - Gas bladder for buoyancy - Holdfast to tether to solid surface - Fronds = their leaves

Question 37

What are the uses of brown algae?

Answer 37

Fertilisers, alginic acid (thickening agent), some edible

Question 38

How can brown algae be used in biofuels?

Answer 38

Mainly Nannochloropsis. Fast growing. Genetically engineered, High levels of lipids, Saltwater species.

Question 39

What technical can be caused by trying to scale algae from a lab to the field?

Answer 39

- Difficult to harvest products - High energy costs - Contamination - Cost effectiveness

Question 40

What are the features of dinoflagellates?

Answer 40

- Alveolate super group - Motile → 2 flagella - Secondary or tertiary endosymbionts - Armoured plate appearance - Horn like appendage - Photoheterotrophs (predate on other plankton) - Responsible for red tides (production of carotenoid)

Question 41

How do dinoflagellates produce and use bioluminescence?

Answer 41

- Flow agitated - Deterrent for predaators - Oxidation of luciferin by luciferase - energy -light

Question 42

What are dinoflagellates symbiotic with?

Answer 42

Foraminiferans, sponges, corals

Question 43

Describe a dinoflagellates symbiosis with coral

Answer 43

- Photosynthesis - Fixed carbon for the coral - Gives coral bright and diverse colours - Affected by global warming