Algae

Question 1

Attached Algae

Answer 1

Freshwater Chara, Brown Algae, Red Algae

Question 2

Freshwater Chara

Answer 2

attached green algae, large multicellular growth forms, NOT PART OF phytoplankton, Serve as food/habitat for other organisms; Often leads to increased species diversity, very important in food web; Also considered to be ancestral group to LAND PLANTS

Question 3

 Brown Algae(Stremenopila)

Answer 3

large attached, multicellular growth forms; marine photoautotrophs, Dominant organism in marine food webs in intertidal(sometimes dewatered by tides) and nearshore(always underwater) habitats; Used as food and habitat/shelter, Grows up into water column

Uses holdfast and gas bladder

Question 4

Holdfast

Answer 4

attaches/anchors itself to bottom, attach to substrate to hold in place

Question 5

Gas Bladder

Answer 5

maintain buoyancy (hold up in water column)

Photosynthetic, so reaching light where it’s needed

Question 6

Role of Brown Algae in Food Webs

Answer 6

Critical role played in food webs as structure(habitat) and food, Have HIGER SPECIES DIVERISTY in areas where present

In recent past, Pacific Ocean kelp forests were disappearing ; Sea Urchin attacks by eating kelp heavily, destroying whole habitats

Question 7

Keystone Species

Answer 7

if organism removed from an ecosystem, the ecosystem changes dramatically and often collapses

Question 8

Critical Example of A Keystone Species

Answer 8

Sea Otter, helps prevent loss of higher species diversity by eating sea urchins;(sea urchins can destroy mass amounts of brown algae, a critical structure in high species diversity as food and habitat; with sea urchins under control, brown algae will maintain diversity)

Question 9

Red Algae(Rhodophyta)

Answer 9

Like other algae they are photoautotrophs, rely on photosynthesis

Color comes from red pigments; allows them to live at deeper depths than other algae (Within red pigment, they can absorb light wave lengths reaching those depths (differs from what hits water surface))

Mostly marine(saltwater) with a few freshwater species; Common on deep water reefs, provide food/habitat for many species, greatly increasing species diversity

Question 10

Common Commercial Usage of Red Algae

Answer 10

Agar, Carrageenan, and Nori

Question 11

Agar

Answer 11

growth medium for microbes in Petri dishes; food thickener (gelatinize food)

Question 12

Carrageenan

Answer 12

food additive used to gel/solidify foods

Question 13

Nori

Answer 13

used to wrap sushi rolls