Page 18 - Kingdom Protist

Chrysophytes Yellow-green algae and golden-brown algae are in the phylum
Chrysophyta and are called chrysophytes.Like diatoms, these algae have yellow and
brown carotenoids that give them their golden brown color. The algae in Figure 3.5
are two examples of organisms from this phylum. Most members of this phylum are
unicellular, but some species form colonies. A colony is a group of cells that join

together to form a close association. The cells of chrysophytes usually contain two
flagella attached at one end of the cell. All chrysophytes are photo synthetic, but some
species also can absorb dissolved organic compounds through their cell walls or ingest
food particles and prokaryotes. They reproduce both asexually and sexually, although
sexual reproduction is rare. Chrysophytes are components of both freshwater and
marine plankton.

Figure 3.5 Chrysophytes, like yellow-
green and golden-brown algae, have
carotenoids—secondary pigments
used in photosynthesis.

Brown algae are members of the phylum
Phaeophytaand are some of the largest
multicellular plantlike algae. These algae get their
brown color from a secondary carotenoid pigment
called fucoxanthin. Most of the 1500 species of
brown algae live along rocky coasts in cool areas

of the world. Look back at Table 19.1 to see kelp,
an example of a brown alga. The body of a kelp is
called the thallus, as shown in Figure 3.6 The
blades are the flattened portions, the stipe is the
stalklike part, the holdfast is the rootlike structure,
and the bladder is the bulging portion of the alga. Figure 3.6 Underwater kelp forests
The bladder is filled with air and keeps the alga provide a habitat for many marine
floating near the surface of the water where light organisms, as well as provide
is available for photosynthesis. algin—an additive used in many

products.

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