AP Biology Reading Guide Chapter Ecosystems Fred and Theresa Holtzclaw Notice that most biomass pyramids have greatest biomass on the bottom of the pyramid. Label the trophic levels on the figure. Explain why the second pyramid of biomass is inverted. AP Biology Reading Guide Chapter Ecosystems Name_____Period_____ Chapter Ecosystems. Overview: 1. What is an ecosystem? 2. Where does energy enter most ecosystems? How is it converted to chemical energy and then You may recall from Chapter 54 that biomass is the total mass of all individuals in a trophic. Chapter 55 - AP Biology Wait just a minute here In order to access these resources, you will need to sign in or register for the website (takes literally 1 minute!) and contribute 10 documents to the CourseNotes library. Something important to remember is the first law of thermodynamics; the law that states energy cannot be created nor destroyed. When energy is put into an ecosystem, all the energy lost must equal all the energy initially put in. For example, all the sunlight energy absorbed by. We hope your visit has been a productive one. If you're having any problems, or would like to give some feedback, we'd love to hear from you. For general help, questions, and suggestions, try our dedicated support forums. If you need to contact the writeanessayforme.pw web .
- A Short Caucasian Bibliography
- Ap Biology (Campbell) Chapter 54: Elaborate Ecosystems
- Chapter 55 - AP Biology
- Chapter 55 - Ecosystems
A Short Caucasian Bibliography
Many cyanobacteria form motile filaments of cells, called hormogonia , that travel away from the main biomass to bud and form new colonies elsewhere. To break away from the parent colony, a hormogonium often must tear apart a weaker cell in a filament, called a necridium. Each individual cell each single cyanobacterium typically has a thick, gelatinous cell wall.
In water columns, some cyanobacteria float by forming gas vesicles , as in archaea. They are not bounded by lipid membranes , but by a protein sheath. Ecology[ edit ] Cyanobacterial bloom near Fiji Cyanobacteria can be found in almost every terrestrial and aquatic habitat — oceans , fresh water , damp soil, temporarily moistened rocks in deserts , bare rock and soil, and even Antarctic rocks.
They can occur as planktonic cells or form phototrophic biofilms. They are found in endolithic ecosystem. Some live in the fur of sloths , providing a form of camouflage.
Ap Biology (Campbell) Chapter 54: Elaborate Ecosystems
The blooms can have the appearance of blue-green paint or scum. These blooms can be toxic , and frequently lead to the closure of recreational waters when spotted.
Marine bacteriophages are significant parasites of unicellular marine cyanobacteria. For this reason blooms of cyanobacteria seldom occur in rivers unless the water is flowing slowly. Growth is also favored at higher temperatures, making increasing water temperature as a result of global warming more problematic. At higher temperatures Microcystis species are able to outcompete diatoms and green algae.
Chapter 55 - AP Biology
This is a concern because of the production of toxins produced by Microcystis. This can lead to serious consequences, particularly the contamination of sources of drinking water. Cyanobacteria can interfere with water treatment in various ways, primarily by plugging filters often large beds of sand and similar media , and by producing cyanotoxins which have the potential to cause serious illness if consumed.
Consequences may also lie within fisheries and waste management practices. Anthropogenic eutrophication , rising temperatures, vertical stratification and increased atmospheric carbon dioxide are contributors to cyanobacteria increasing dominance of aquatic ecosystems. It has been widely reported that cyanobacteria soil crusts help to stabilize soil to prevent erosion and retain water. The tiny marine cyanobacterium Prochlorococcus was discovered in and accounts for more than half of the photosynthesis of the open ocean.
They are the most genetically diverse; they occupy a broad range of habitats across all latitudes, widespread in freshwater, marine, and terrestrial ecosystems, and they are found in the most extreme niches such as hot springs, salt works, and hypersaline bays. Photoautotrophic , oxygen-producing cyanobacteria created the conditions in the planet's early atmosphere that directed the evolution of aerobic metabolism and eukaryotic photosynthesis.
Cyanobacteria fulfill vital ecological functions in the world's oceans, being important contributors to global carbon and nitrogen budgets. Carbon fixation[ edit ] Cyanobacteria use the energy of sunlight to drive photosynthesis , a process where the energy of light is used to synthesize organic compounds from carbon dioxide. Because they are aquatic organisms, they typically employ several strategies which are collectively known as a "carbon concentrating mechanism" to aid in the acquisition of inorganic carbon CO2 or bicarbonate.
Among the more specific strategies is the widespread prevalence of the bacterial microcompartments known as carboxysomes. It is believed that these structures tether the CO2-fixing enzyme, RuBisCO , to the interior of the shell, as well as the enzyme carbonic anhydrase , using metabolic channeling to enhance the local CO2 concentrations and thus increase the efficiency of the RuBisCO enzyme.
While the goal of photosynthesis is to store energy by building carbohydrates from CO2, respiration is the reverse of this, with carbohydrates turned back into CO2 accompanying energy release. Cyanobacteria appear to separate these two processes with their plasma membrane containing only components of the respiratory chain, while the thylakoid membrane hosts an interlinked respiratory and photosynthetic electron transport chain.
In contrast to green sulfur bacteria which only use one photosystem, the use of water as an electron donor is energetically demanding, requiring two photosystems.
In some cyanobacteria, the color of light influences the composition of the phycobilisomes. Thus, the bacteria appear green in red light and red in green light. A few genera lack phycobilisomes and have chlorophyll b instead Prochloron , Prochlorococcus , Prochlorothrix. These were originally grouped together as the prochlorophytes or chloroxybacteria, but appear to have developed in several different lines of cyanobacteria.
For this reason, they are now considered as part of the cyanobacterial group.
Chapter 55 - Ecosystems
Carbon dioxide is reduced to form carbohydrates via the Calvin cycle. They are known to have evolved from cyanobacteria through endosymbiosis , i. In this case, a photosynthesizing cyanobacteria that was engulfed in some ancient eukaryotic cell. The cyanobacterial origin of plastids is now supported by various pieces of phylogenetic ,    genomic ,  biochemical   and structural evidence.
In other words, all the oxygen that makes the atmosphere breathable for aerobic organisms originally comes from cyanobacteria or their later descendants. Cyanobacteria possess numerous E.
For bacterial transformation to take place, the recipient bacteria must be in a state of competence , which may occur in nature as a response to conditions such as starvation, high cell density or exposure to DNA damaging agents. In chromosomal transformation, homologous transforming DNA can be integrated into the recipient genome by homologous recombination , and this process appears to be an adaptation for repairing DNA damage.
The first three — Chroococcales , Pleurocapsales , and Oscillatoriales — are not supported by phylogenetic studies. The latter two — Nostocales and Stigonematales — are monophyletic, and make up the heterocystous cyanobacteria.
The classic taxonomic criterion has been the cell morphology and the plane of cell division. In Pleurocapsales, the cells have the ability to form internal spores baeocytes. The rest of the sections include filamentous species.
In Oscillatoriales, the cells are uniseriately arranged and do not form specialized cells akinetes and heterocysts. Stigonematales, unlike Nostocales, include species with truly branched trichomes.