Page 19 - Kingdom Protist

The diverse group of algae from the
phylum Chlorophyta contains more than 7000
species. Green algae have several
characteristics in common with plants. Green
algae and plants both contain chlorophyll as a

primary photosynthetic pigment, which gives
both groups a green color. Both green algae
and plant cells have cell walls, and both
Desmids
groups store their food as carbohydrates.
These shared characteristics lead some
scientists to think there is an evolutionary link
between these two kingdoms.

There are a variety of growth patterns
exhibited by green algae. The unicellular

algae Desmids, shown in Figure 3.7 are
characterized by their symmetrically divided
Spirogyra
cells. Notice how the cells have two identical
sides that are connected by a bridge. Another
growth pattern is found in Spirogyra, shown
in Figure 3.7 Spirogyra is a multicellular green
algae characterized by its long, thin filaments.
The name Spirogyra comes from the spiral
pattern of the chloroplasts. Volvox, shown in
Figure 3.7 is an example of an alga that has a

Volvox colonial growth pattern.

The single cells of the Volvox colony are
Figure 3.7 Desmids are unicellular held together by a gelatin like secretion called
green algae that have elaborate cytoplasmic strands. Each cell has flagella that
cell walls. The green alga Spirogyra beat in unison to move the colony. Volvox
is named for its spiraling
colonies might include hundreds or even
chloroplasts. Many cells that make
thousands of cells that form a hollow ball.
up the Volvox colony have
Smaller colonies, called daughter colonies,
daughter colonies within the larger
form balls inside the larger colony. When the
colony.
daughter cells have matured, they digest the

parental cell and become free-swimming.

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