OBSERVING LIVING PROOF OF EVOLUTIONARY TRENDS ALGAE OBSERVING LIVING PROOF OF EVOLUTIONARY TRENDS
DISTINGUSHING CHARACTERISTICS OF ALGAE
ALL AGLAE: 1. Photosynthetic 2. Live in aqueous environments (ie. In or near water) 3. Lack internal tubes to move water and materials from one part of the plant to another
ALL ALGAE: 5. Cells have a cell wall 6. Contain chlorophyll a (sometimes other forms of chlorophyll also) 7. Complicated alternating sexual & asexual reproduction cycles
WHAT KINGDOM ARE THEY · Unicellular algae = Kingdom Protista · · Multicellular algae = Kingdom Plantae
GROUPS OF ALGAE CLASSIFIED ACCORDING TO TYPES OF CHLOROPHYL & ACCESORY PIGMENTS THEY HAVE
GREEN ALGAE = PHYLUM CHLOROPHYTA CONTAIN CHOROPHYLLS a & b STORE FOOD AS STARCH
BROWN ALGAE = PHYLUM PHAEOPHYTA CONTAIN CHLOROPHYLLS a & c ALSO CONTAIN FUCOXANTHIN ACCESORY PIGMENT
RED ALGAE = PHYLUM RHODOPHYTA CONTAIN CHOROPHYLL a & sometimes d ALSO HAVE PHYCOBILIN ACCESORY PIGMENTS LIVE DEEPER IN THE OCEANS BECAUSE PHYCOBILIN IS VERY EFFICIENT AT ABSORBING BLUE LIGHT
Forms of Algae
Unicells: single cells, motile or nonmotile
Colonies: Assemblage of individual cells with variable or constant number of cells that remain constant throughout the colony life
Coenobium: Colony with constant number of cells, which cannot survive alone; specific „tasks“ among groups of cells is common
Filaments: daughter cells remain attached after cell division and form a cell chain; adjacent cells share cell wall
MULTICELLULAR
MAJOR THEMES WE ARE LOOKING AT EVOLUTION FROM UNICELLULAR TO MULTICELLULAR (Tomorrows Lab) EVOLUTION OF SEXUAL REPRODUCTION (next week) DOMINANT HAPLOID DOMINANT DIPOID ADVANTAGES & DISADVANTAGES OF AQUATIC ENVIRONEMENT(next Tuesday)