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)