Study Set Content:
among the best known and economically most important members of the phylum.
Diatoms
These mostly unicellular algae occur in astronomical numbers in fresh and saltwater but are particularly abundant in
colder marine habitats.
living species of diatoms
500
one species is known to have become active after lying dormant in dry soil for 48 years.
one species is known to have become active after lying dormant in dry soil for 48 years.
As much as 95% of the wall content of diatoms is
silica
scientists who specialize in the study of algae
phycologists
When phycologists (scientists who specialize in the study of algae) want to examine the markings on diatom walls, they often obtain a better view by dissolving the cell contents with
hot acid
the chlorophyll that is present in diatoms
chlorophyll c1 and chlorophyll c2
number of seaweeds of brown algae
1,500 species of seaweeds and other algae
term for multicellular bodies that are usually flattened and not organized into leaves, stems, and roots) that is differentiated into a holdfast, a stipe, and flattened, leaflike blades
thallus or thalli
Since the meristem of the brown algae produces new tissue at the base, the oldest parts of the blades are at the
tips
main food reserve of brown algae
lamanarin
occurs on or in the cell walls and can represent as much as 40% of the dry weight of some kelps.
algin or alginic acid
Reproductive cells of brown algae are unusual in that the two flagella are inserted
laterally
The only motile cells in the brown algae are KINGDOM PROTISTA 14 the
reproductive cells
number of species of red algae
5,000
Red algae
PHYLUM RHODOPHYTA
have relatively complex life cycles, often involving three different types of thallus structures.
PHYLUM RHODOPHYTA
Meiosis usually occurs on a thallus called a
tetrasporophyte
a feathery red alga that is widespread in marine waters, the three types of thalli (male gametophyte, female gametophyte, and tetrasporophyte) all outwardly resemble one another.
Polysiphonia
