Kingdom Protista

Phylum Chrysophyta - Diatoms and Golden Algae
Diatoms are photosynthetic, unicellular organisms
Double shells of silica - Resemble box with lid
Use chlorophylls a and c, and carotenoids
fossilize well - thick sediments of fossil
diatoms are called “diatomaceous earth”
Some move by secretions from shell
Asexual reproduction separates shell halves
each half produces new shell within old
one - become smaller with each division
Have gametic meiosis - cells are diploid
and produce sperm or eggs by meiosis
Golden Algae - use yellow and brown carotenoid pigments, and
xanthophyll accessory pigments
Unicellular, two flagella, often colonial, common in freshwater
Form resistant cysts when ponds dry out in summer