KINGDOM PROTISTA (specifically plant like protists) DOMAIN EUKARYA KINGDOM PROTISTA (specifically plant like protists)

Plantlike protists contain chlorophyll and carry out photosynthesis. Plantlike protists are commonly called “algae.” The four phyla of unicellular algae are: euglenophytes chrysophytes diatoms dinoflagellates

Copyright Pearson Prentice Hall Euglenophytes Pellicle Euglena Contractile vacuole Carbohydrate storage bodies Chloroplast Nucleus Euglenophytes are plantlike protists that have two flagella but no cell wall. Eyespot Gullet Flagella Copyright Pearson Prentice Hall

Chrysophytes Members of the phylum Chrysophyta are a diverse group of plantlike protists that have gold-colored chloroplasts.

Diatoms Diatoms produce thin, delicate cell walls rich in silicon (Si)—the main component of glass. The walls are shaped like the two sides of a petri dish or flat pillbox, with one side fitted snugly into the other.

Dinoflagellates About half of the dinoflagellates are photosynthetic; the other half live as heterotrophs. Dinoflagellates have two flagella that fit in grooves between two thick plates of cellulose that protect the cell.

Phytoplankton Phytoplankton constitute the population of small, photosynthetic organisms found near the surface of the ocean. Phytoplankton carry out half of Earth’s photosynthesis. In addition, they provide nourishment for many organisms.

Algae The three phyla of algae that are largely multicellular are: red algae brown algae green algae As green algae are thought to be the ancestors of terrestrial plants we will focus on them.

Green Algae Life History Green algae live in fresh and salt water, and moist land areas. Many species live most of their lives as single cells. Others form colonies, groups of similar cells that are joined together but show few specialized structures. The life cycles of many algae include both a diploid and a haploid generation. This is known as alternation generations Many alga also shift between sexual and asexual reproduction

Reproduction in Chlamydomonas The unicellular Chlamydomonas spends most of its life in the haploid stage.

Reproduction in Ulva  The life cycle of the green alga Ulva involves alternation of generations. Ulva are gametophytes, or gamete-producing plants.

Human Uses of Algae Algae is found in sushi, ice cream, and other foods. Chemicals from algae are used to make plastics, waxes, transistors, deodorants, paints, lubricants, and artificial wood. Agar thickens nutrient mixtures in scientific labs.

Evolutionary Significance

Plant Evolution and Adaptations When scientists compare present-day plants and present-day green algae, they find the following common characteristics: cell walls composed of cellulose cell division that includes the formation of a cell plate the same type of chlorophyll used in photosynthesis similar genes for ribosomal RNA food stored as starch the same types of enzymes in cellular vesicles