Nadia Langha Biology 106 Honors Project

Transcription

1 Nadia Langha Biology 106 Honors Project

2 Cyanobacteria Domain Bacteria Division Cyanophyta Cyanobacteria also known as BlueGreen Algae -Cyano=blue Bacteria are more closely related to prokaryotic bacteria than eukaryotic bacteria. Cyanobacteria were the first algae!

3 More Characteristics of Cyanobacteria Cyanobacterial cells may be spherical or rod-shaped. Round bacteria = coccus & Rods = bacillus Many form colonies, long filaments of cells strung together, in which every cell is capable of living alone and carrying out all life functions. Colony formation led to multicellularity, that also occurs in Kingdom Protista. They can be slimy or slippery due to a gelatinous layer that surrounds their cell walls. They have a prokaryotic flagellum that allows locomotion but can also glide with their gelatinous layer.

4 Effects of Cyanobacteria on Humankind Cyanobacteria are autotrophs, or organisms that don t feed on other organisms, but make their own food from solar or chemical energy.

5 Cell Types in Typical Chain Vegetative cells photosynthesize and release O2 gas and sugar. Heterocysts specialized and bigger cells that create: - An oxygen-free environment, that allows nitrogenase enzyme to fix nitrogen. - Acts as a floatation device so strands rise to surface for photosynthesis to occur. - Form weak points of attachment that break easily, leading to new formation colonies. Spores tiny reproductive cells that can resist harsh conditions that can grow into new filaments again after being exposed to suitable conditions.

6 Cell Types in Typical Chain Vegetative cells Heterocysts Spores

7 Intro to Pictures & Examples of Cyanobacteria as seen in Lab -Oscillatoria sp. -Anabaena sp.

8 Oscillatoria sp.

9 Anabaena sp.

10 Not seen in Lab, but extra examples of cyanobacteria -Spirulana -Lyngbya (These two still demonstrate characteristics of Anabaena/Oscillatoria)

11 Spirulana

12 Lyngbya

13 Habitats Cyanobacteria can occur in fresh water, where they form pond scum, as well as salt water and moist terrestrial environments. Important functions in different environments.

14 Nitrogen Fixation Enriches soil by converting N2 gas from the atmosphere into nitrogen compounds nitrogen fixation. Makes proteins through nitrogen fixation. Nitrogenase - enzyme that fixes nitrogen that only works in cells where oxygen is absent.

15 Photosynthesis Contains chlorphyll a, a light-capturing pigment important in photosynthesis.

16 Photosynthesis (cont d) Cyanobacteria uses light and CO2 from the atmosphere to make food sugars. They then release O2 back to the atmosphere.

17 Lichens Lichens have a close association between a fungus and a photosynthetic organism such as an alga or cyanobacterium. Alga or cynaobacterium supplies food for the lichen from its photosynthetic activity. Fungus anchors lichen to the substrate, encloses the chlorophyllbearing organism in a moist environment, and gives it necessary nutrients (e.g. nitrogen & phosphorus) to survive. True symbiotic relationship: the fungus could live without the photosynthesizer, but it would be limited by food availability; the algae/cyanobacteria could live without the fungus, but it would be limited by water/moisture availability. Together they can survive in conditions that neither alone could.

18 Lichens (cont d) Lichens play an important role in the process of soil formation. They penetrate rocks and break the rock particles into soil. Some nitrogen-fixing lichens add nitrogen to the newly forming soil. Many lichens are adapted to withstand extremely cold temperatures and can endure extreme desiccation (drying out), most are extremely fragile to air pollution.

19 Lichens (cont d) Thallus body of a lichen -Thallus lacks flowers, stems, roots, and leaves. Ascomycotes fungi that form the body of almost all lichens and produce asci in ascocarps.

20 Lichens (cont d) Crustose Flat and tightly attachd to the substrate. Most commonly found on rocks. Fruticose Seem to be branched and extend upward away from the substrate on which the lichen is growing. It is sometimes commonly mistaken for moss and are abundant on the north surfaces of trees. Foliose Has bodies divided into leaf-like thalli (plural:thallus) that are different on the upper and lower surfaces.

21 Photos of Lichen

22 Crustose

23 Fruticose

24 Foliose

25 Identification Practice

26 Name the Domain

27 Domain Bacteria

28 What division does cyanobacteria belong to?

29 Division Cyanophyta

30 Are these multi-cellular or unicellular organisms?

31 Unicellular or colonial

32 Prokaryotic or Eukaryotic?

33 Prokaryotic

34 Identify an example of each of the three cell types in this typical cyanobacteria chain

35 Vegetative cells, heterocysts, and spores

36 Are cyanobacteria autotrophic or heterotrophic?

37 Autotrophic

38 What type of lichen is this?

39 Fruticose

40 Name the other 2 types of lichen growth forms

41 Crustose & Foliose

42 Name one beneficial result of lichen

43 Soil formation