1. Cell membrane. All cells have a phospholipid based cell membrane. The cell membrane is selective, and it is permeable in that it allows some materials to pass into or out of the cell but not others.
2.Cytoplasm. Cells are filled with a complex collection of substances in a water based solution. This substance is called cytoplasm. Across all cells there are a number of common features to all cell cytoplasm. For instance, all cells have ribosomes. In addition, in all cells, the first steps in cellular respiration take place in the cytoplasm.
3.DNA. All cells contain DNA. In the simplest cells, the DNA is in one loop like structures free in the cytoplasm. In some cells (such as those making up our body), the DNA is isolated from the cytoplasm. It is in a special structure called a nucleus. However, not all cells have a nucleus
2. Use a 4-Point concept map (see Study Skill Technique web site) to define and describe the characteristics of the Kingdom Monera.
(7 marks)
CHARACTERISTICS
Def: none karyon cell.,low level living creature
karyotheca
nucleoid
MONERA
Shapeless karyon
Exposed DNA
EXAMPLES
blue algae
germ
3. Use a comparison-contrast organizer (see Study Skill Technique web site) to illustrate Moneran diversity with respect to their form, distribution (i.e. where they are found), motility, ecological role (i.e. how they help the environment), nutrition requirements, and the few that cause human disease. (6 marks)
Attribute
Description
Form
Spherical or Cocci bacteria occur singly or in pairs (diplococci) firstly in clusters resembling bunches of grapes (staphylococci) and secondly in chains of many cells (streptococci). Rod-shaped bacilli are most usually solitary, but there are also forms with the rods arranged in chains as an exception. In nature, the majority of monerans are single-celled while some species tend to aggregate reversibly in two-celled to several celled groups. Others have the form of true colonies (permanent aggregates of identical cells). Specially, Spirilla are spiral shaped bacteria reminiscent of corkscrews.
Distribution
Prokaryotes are the most pervasive of organisms. They thrive in all habitats of the earth, including hot, cold, salty, acidic habitats that cannot be imagined. Some prokaryotes even grow and thrive rapidly in environments as hot as 100 degrees celcius or as acidic as pH 2 [thermoacidophiles]. The bacteria living in the Dead Sea tolerate extreme halophiles. Methanogens - live in swamps and marshes where other microbes have consumed all the oxygen but it doesn't matter for them. The methane that bubbles out is known as marsh gas.
Motility
Monerans have three different ways of moving.
1. Many of them move by rotating. When the flagella are rotated in one direction, the monerans move in a straight line, so that they rotates in the other direction they tumble.
2. Some bacteria secrete slimy chemicals and move by a gliding motion.
3. Spirochetes use filaments that wrap around the cell to move them like a corkscrew through the viscous fluids they inhabit.
Ecological Role
The great majority of prokaryotic species are essential to all life on Earth. If all prokaryotes suddenly perish for some reasons, the chemical cycles would undoubtedly halt, and consequently all other forms of life would be doomed. The nitrogen, carbon, and other elements would become locked in the organic molecules of feces and corpses
Nutrition Requirements
Most prokaryotes are heterotrophic. Of these the majority are saprobes. They feed on the dead because of the specificity of bacterial nutritional requirements
Human Disease Causing?
The prokaryotes are bacteria. Some are water dwellers, some are soil dwellers. What' more, some inhabit in plants and animals. Some, but not all species of bacteria are capable of causing disease.
4. Use a comparison-contrast organizer (see Study Skill Technique web site) to differentiate among Moneran fermentation, aerobic respiration, and photosynthesis. (3 marks)
Process
Description
Fermentation
colon bacillus Fermentation,inner-cell Fermentation,and it must go through cytoclasis
Aerobic Respiration
aerobic respiration, enzyme on cytoplasmic matrix,some are anaerobic respiration
Photosynthesis
Some have chloroplast which can surport Photosynthesis
5. Contrast the ways in which bacterial (i.e. Moneran) decomposers and parasites obtain their food. (2 marks)
______________________________________________________
Usually, decomposers break down dead organisms while parasites attach to feed off living ones ___________________________________________________
6. List and describe four examples of the beneficial roles of bacteria. (4 marks)
Example
Description
Bioremediation
The use of biological agents (such as bacteria or plants) to neutralize or remove contaminants in contaminated soil and water
Decomposing
There are saprophytic organisms (mainly bacteria and fungi) that live on dead animals and plants. In terrestrial ecosystem, usually, bacteria act on animal tissue and fungi on plants, but there also may be some exceptions. This group of organisms plays a vitally important role in releasing back the biotic components into the environment by digesting the dead tissue through enzyme secretion. It can be made available for reuse by the producers to be built into organic compounds again. As a result, it can be seen that matter circulates in nature: though the constantly changes of its form, there is no overall loss or gain in nature.
Nitrogen Fixation
Bacteria involved in the nitrogen cycle:
Nitrogen fixing bacteria: It is in the nodules of legumes and converts free N into nitrates;
Bacteria of decay: It recycles organic matter back into the earth;
Nitrifying bacteria: It converts ammonia into nitrates;
Denitrifying bacteria: It converts nitrates into free N.
Recombinant DNA
Recombinant DNA technology allows scientists to transplant a gene for a particular protein into rapidly reproducing bacteria in order to mass produce the protein. On the other way, it can be inserted into the genome of a crop providing a certain benefit. As a result, bacteria have got used to produce human insulin. Additional therapies and production were carried out since 1978, and nowadays, this technology is gaining more application in pharmacology as well as in agriculture.
7. Why has the effectiveness of many antibiotics diminished over the past few decades? (2 marks)
Because they have been used so much the infections, the effectiveness of antibiotics has diminished. The infections they used to be were so effective so that they are resistant to the antibiotic, or even immune to it.
8.a. You no doubt have noticed the widespread advertisement of antibacterial soaps/cleaners. Discuss reasons why these soaps/cleaners not only don't work any better than regular soaps/cleaners, they may actually lead to bacterial resistance. End with your opinion on the controversy. (7 marks)
(Use the internet to research the question above and develop your own opinion. Include at least three sources of information in a brief bibliography at the bottom of the page. (3 marks).
Allison Aiello, PhD, assistant professor of epidemiology at the University of Michigan, headed a group that analyzed several studies comparing people who washed their hands with regular or antibacterial soap. In all but one trial, she tells WebMD, "There was no difference between groups, either in bacteria on the hands or in rates of illness." In a single study, people who used antibacterial soap did have fewer bacteria on their hands, but only if they washed for 30 seconds, 18 times a day, for five days straight.
"Also, antibacterial ingredients don't kill viruses, which cause the vast majority of minor illnesses people experience," she adds. That includes colds, flu, and stomach bugs.
Though Antibacterial soap's potential to harm people may be controversial, it is widely known that there is is an impact on growing environment. The ingredients in antibacterial cleansers are building up in the environment at an alarming rate.
Rolf Halden, PhD, is associate professor at Arizona State University's Biodesign Institute. According to his opinion, several million pounds of triclosan and triclocarban are produced annually (Here, it is an antibacterial chemical in bar soap). Much of it is flushed or rinsed down drainpipes. "Water treatment plants don't process the chemicals well. They end up in surface waters, frequently at concentrations that are toxic to aquatic life," Halden says.
The antibacterial soap's impacts on human and environmental health are being examined now. An FDA advisory committee found potential risks rather than benefit to antibacterial over regular soap. This finding opened the door to tighter regulation.
Some scientists feel that change is already overdue. In Halden's view, "without any demonstrated benefit, and with the clear risks to the environment and possibly our health, it's difficult to justify the ongoing use of these products. Dan Chang, PhD, a professor of environmental engineering at U.C. Davis and one of the researchers involved, says "the public should be aware of some of the concerns
The stakes are high for the manufacturers: Antibacterial products account for about $1 billion in sales annually. Triclosan is found in 76% of all liquid soap sold in stores and is also added to toothpaste, mouthwash, cosmetics, fabrics, and plastic kitchenware. Triclocarban is a common additive in antibacterial bar soap and deodorant.
For the reasons above, I think publicity should be made to raise the awareness of general public and tougher measures taken in manufacturing the antibacterial soaps/ cleaners.
