Presentation on theme: "Introduction to Algology (Phycology)"— Presentation transcript:
1 Introduction to Algology (Phycology) What is Algology (phycology):Algoloy is the science (gr. logos) of algae (L. algae).Phycology is the science (gr. logos) of algae (gr. phycos). This discipline deals with the morphology, taxonomy, phylogeny, biology, and ecology of algae in all ecosystems
2 FOSSIL HISTORY OF ALGAE 3.5 billion yrs agoCyanobacteria—first algaeProkaryotes—lack membrane bound organellesLater eukaryotes evolved—mitochondria, chloroplasts, and chromosomes containing DNA.
3 BOTANICAL NOMENCLATURE Binomial nomenclature—Ulva lactucaBinomial Nomenclature was proposed by Linnaeus in Cited in Species Plantarum.Type Specimen—The specimen from where the description is made. Collected and placed in a herbarium. Herbarium label—species name, location, date of collection, habitat, name of collector and identifier)
4 ALGAE How are algae similar to higher plants? How are algae different from higher plants?
5 Similarities Presence of cell wall—mostly cellulosic. Autotrophs/Primary producers—carry out photosynthesisPresence of chlorophyll a
6 DifferencesAlgae lack the roots, stems, leaves, and other structures typical of true plants.Algae do not have vascular tissues—non vascular plantsAlgae do not form embryos within protective coverings—all cells are fertile.Variations in pigments.Variations in cell structure—unicellular, colonial and multicellular forms.
7 Variations in the pigment constitution Chlorophylls (green)Carotenoids (brown, yellow or red)Phycobilins (red pigment-phycoerythrinblue pigment –phycocyanin)
8 Where are algae abound?Kelp forest up to 50 m high are the marine equivalent to terrestrial forest; mainly built by brown algae
9 Some algae encrust with carbonate, building reef-like structures; cyanobacteria can from rock-like structures in warm tidal areas: stromatolites
10 Algae grow or are attached to animals and serve as camouflage for the animal
11 Algae live as symbionts in animals such as Hydra, corals, or the protozoan ciliate Paramecium; Chlorella in corals they are referred to as zooxanthellae
12 Small algae live on top of larger algae: epiphyton Algae in free water: phytoplankton
13 Terrestrial algaeAlgae have adapted to life on land and occur as cryptobiotic crusts in desert and grassland soils or endocryptolithis algae in rocks
14 Algae live on the snow cover of glaciers and in the brine channels of sea ice
15 A symbiosis of algae and fungi produced the lichens, which are pioneer plants, help convert rock into soil by excreting acids, stabilize desert soil, are sensitive to air pollution
17 Algae can cover trees or buildings green or live in the hollow hairs of ice bears
18 Algal Blooms Algae can be so dominant that they discolor the water Higher amounts of nutrients are usually the causeAlgal blooms can have harmful effects on life and ecosystem:Reduced water clarity causes benthic communities (see grass) to die offFish kills are common effects50% of algal blooms produce toxins harmful to other organisms, including humansAlgal blooms produce a shift in food web structure and species compositionAlgal blooms can mostly be linked to sewage input or agricultural activities, leading to nutrient pollution: eutrophication
20 Unicells: single cells, motile or nonmotile Forms of AlgaeUnicells: single cells, motile or nonmotile
21 Colonies: Assemblage of individual cells with variable or constant number of cells that remain constant throughout the colony life
22 Coenobium: Colony with constant number of cells, which cannot survive alone; specific „tasks“ among groups of cells is common
23 Filaments: daughter cells remain attached after cell division and form a cell chain; adjacent cells share cell wall (distinguish them from linear colonies!); maybe unbranched or branched
24 Siphonaceaous forms: one large, multinucleate cell without cross walls
25 Parenchymatous and pseudoparenchymatous algae: mostly macro-scopic algae with tissue of undifferentiated cells and growth originating from a meristem with cell division in three dimensions; pseudoparenchymatous superficially ressemble parenchyma but are composed of appressed filaments
27 REPRODUCTION Sexual-Gametes Vegetative Cell divisions/Fragmentation =part of the filamentbreaks off from the rest and forms a new one.Asexual ReproductionZoospores after losing their flagella,form new filaments. No sexual fusion.
28 SEXUAL REPRODUCTIONISOGAMY-Both gametes have flagella and similar in size and morphology.ANISOGAMY-Gametes have flagella but are dissimilar in shape and size. One gamete is distinctly smaller than the other one.OOGAMY-gamete with flagella (sperm) fuses with a larger, non flagellated gamete (egg).
33 Can algae provide a renewable source of energy Oil is very important fossil fuels comes from diatom remains.The energy we extract from fossil fuels was originally stored in organisms through the process of photosynthesis.Why wait millions of years?