Question
click below
click below
Question
Normal Size Small Size show me how
BIOLOGY - algae
test tomorrow!
Question | Answer |
---|---|
define algae. | autotrophic, contains chrlorophyll A and carry out photosynthesis |
what kingdom do algae belong to? | protista |
true or false: algae are autotrophic and are considered plant-like because they contain chlorophyll and carry out photosynthesis | true |
what percentage of the world's atmospheric oxygen does algae produce? | 90% |
why are most algae found floating near the surface of fresh and salt water? | because they require sunlight |
true or false: there are algae that are multicellular and some that are unicellular. | true |
how large can algae grow to be? | 70 meters/230 feet |
define plankton. | the mass of mostly microscopic organisms that float freely in the waters of aquatic environments |
true or false: algae make up the ocean's plankton. | true |
what is the largest food source of water dwelling organisms? | plankton |
how are algae classified? | according to the pigments they contain |
CHRYSOPHYTA is? | golden algae, its unicellular. contains 12,000 species and shelled organisms, have a cell wall of silica; example: diatoms, which have 2 identical halves |
PYRROPHYTA is? | fire algae, its unicellular. 1,100 species, red colored; make up the ocean's phytoplankton. |
what is the largest group of fire algae? | dinoflagellates; these are the algae responsible for red tide, caused when algae blooms |
CHLOROPHYTA is? | green algae, its multicellular. 7,000 species exist in this phyla. only a few species are marine, most are freshwater and they range from microscopic up to 8m long, they are similar to greem plants on land. examples: volvox and spirogyra |
PHAEOPHYTA is? | brown algae, its multicellular. 1,500 species; nearly all species are marine, are found on rocky coasts and in cooler waters |
what does an air bladder do? | it helps keep large seaweed and kelp stay afloat |
what is the largest of the algae? | brown algae (phaeophyta) |
true or false: brown algae is important economically? | true |
RHODOPHYTA is? | red algae, its multicellular. 4,000 species. found in many places, but common in tropical oceans and are almost entirely marine. the colors can range from yellow, reddish-purple, and red. they grow in deeper waters than other algaes. |
what allows the aborption of blue light? | phycobillins. |
diatoms are in what classification? | golden algae (chrysophyta) |
most species are freshwater and similar to plants. | green algae (chlorophyta) |
makes up the ocean's phytoplankton. | fire algae (pyrrophyta) |
what is responsible for red tide? | dinoflagellates |
the largest of the algae. | brown algae (phaeophyta) |
almost all entirely marine, they grow in deeper water than other algae. | red algae (rhodophyta) |
true or false: multicellular algae lack true roots, stems, leaves, flowers, fruits, and seeds. | true |
define thallus. | the simple body of a multicellular algae |
what 3 things are a thallus composed of? | 1) hold fast 2) stipe 3) blade |
what is a hold fast? | root-like extension, doesn't nourish a true root |
what is a stipe? | stem-like area, flexible; functions to allow blades to be close to the surface for light absorption |
what is a blade? | leaf-like area, site of sexual reproduction |
what of 2 ways do algae reproduce? | sexual & asexual |
what 3 groups of algae contain seaweed? | green, red, and brown |
what variety of products is seaweed a source of? | food (primarily in Asian nations), potash (important fertilizer), & iodine (primarily in Russia) |
true or false: algin has the ability to absorb great quantities of water, used in foods, medicines, etc. | true |
what do microbes grow on, also found in canned foods and cereals? | agar |
what product is used in foods as a thickening agent? | carrageenan |
define diatom. | a unicellular alga that has a double shell that contains silica |