Chapter 20: Multicellular Algae Characteristics of Algae -Algae are photosynthetic organisms <Tab/>-Live in streams, ponds, lakes, oceans, and swamps <Tab/>-Must live in or near a source of water -Algae lack an internal system -Algae lack an internal system of tubes to move water and materials from one part to another <Tab/>-Water in which algae live provides CO2, oxygen, nutrients, and carries …showed first 75 words of 6002 total…

…showed last 75 words of 6002 total…colored accessory pigments appear (autumn foliage) Day Length and Flowering -Photoperiodicity is the response of plants light and dark periods is called <Tab/>-Plants time their flowering according to number of hours of light/darkness received -Short day plants flower because accumulation of certain type of phytochrome during period of darkness triggers flowering (long nights) -Long day plants flower because nights are short <Tab/>-Petunias, hollyhocks, clovers