Algal groups- Red, Brown and Green algae

Question 1

what are the names for the phyla of red, green and brown algae

Answer 1

Red- Rhodophyta
Green- Chlorophyta
Brown- Phaeophyta

Question 2

which kingdoms do the red, green and brown algae belong to

Answer 2

Red and green= plantae
brown= chromista

Question 3

why are macroalages different colours

Answer 3

sunlight differs in intensity and quality at different depths, white light is at the surface and only blue-green at more than 50m so macroalgae pigments are adjusted accordingly

Question 4

outline some characteristics of phaeophyta

Answer 4

• almost entirely marine
• seaweeds of temperate, boreal and polar waters
• 1500 species
• dominate rocky shores throughout cooler regions of the world

Question 5

give some examples of some species in the phyla phaeophyta

Answer 5

• bladder wrack
• kelp (laminariales)

Question 6

outline brown algae body form

Answer 6

can be taller than a tree but less than 5cm thick
basic form is a thallus- undifferentiated vegetative body

Question 7

what is a holdfast

Answer 7

a physical link to substrate

Question 8

what is a stipe

Answer 8

a flexible link between fronds and holdfast

Question 9

what is a frond

Answer 9

aka a balde
a photosynthetic, held straight to prevailing current, expose both sides to light

Question 10

what are pneumatocysts

Answer 10

• airbladders which aid some species in buoyancy

Question 11

what does algin and cellulose provide to brown algae body form

Answer 11

along with cellulose they provide flexability and toughness to withstand mechanical stress

prevents desiccation at low tide and increase buoyancy

Question 12

what is the name of the pigment which gives brown algae its colour

Answer 12

fucoxanthin and carotenoids

Question 13

what is the storage material in brown algaes

Answer 13

carbohydrate laminarin which can make up 34% of the weight

Question 14

outline some characteristics of the phyla Rhodophyta

Answer 14

98% marine
abundant in tropical, warm waters
4000-6000 species
only a few are unicellular

Question 15

what pigment gives rhodophyta their red colours

Answer 15

phycoerythin

Question 16

what is the main food reserve in red algae

Answer 16

floridean startch stored in the cytoplasm

Question 17

outline the characteristics of red algae cell walls

Answer 17

thin layer of cellulose
thick layer of slimy mucilaginous compounds
= agar or carrageenan

Question 18

outline some characteristics of the phyla chlorophyta

Answer 18

very diverse
7,000 species
90% freshwater
most microalgae
simple colonial
complex multicellular

Question 19

what are some symbiotic associations with green algae

Answer 19

lichens
protozoans
sponges
cnidarians

Question 20

how are green algaes traditionally grouped

Answer 20

outward structure e.g. unicellular flagellates, filamentous types

Question 21

what are the three groups of green alage looked at

Answer 21

chlorophycease
ulvophyceae
charophyceae

Question 22

what do green algaes produce to maintain an osmotic potential

Answer 22

glycerol

Question 23

what are some products from macroalgaes

Answer 23

• direct food source
• agar
• used to thicken and emulsify
• prserve food and drinks