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applied science - unit 17 A and B - microbiology - Distinction
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- PEARSON (PEARSON)
this is a document is the combination of unit 17 A and B . they were graded distinction my teacher
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Microbiology AssignmentWhat are microorganism?
Microbiology is the study of all living organisms that are too small to be visible with the naked eye.
This includes bacteria, archaea, viruses, fungi, prions, protozoa and algae, collectively known as
'microbes'. These microbes play key roles in nutrient cycling, biodegradation/bio deterioration,
climate change, food spoilage, the cause and control of disease, and biotechnology. Thanks to their
versatility, microbes can be put to work in many ways: making life-saving drugs, the manufacture of
biofuels, cleaning up pollution, and producing/processing food and drink.
What are bacteria and where do they lives ?
Bacteria are single celled microbes. The cell structure is simpler than that of other organisms as
there is no nucleus or membrane bound organelles. Instead, their control centre containing the
genetic information is contained in a single loop of DNA. Some bacteria have an extra circle of
genetic material called a plasmid. The plasmid often contains genes that give the bacterium some
advantage over other bacteria. For example it may contain a gene that makes the bacterium
resistant to a certain antibiotic.
Bacteria are found in every habitat on Earth: soil, rock, oceans and even arctic snow. Some live in or
on other organisms including plants and animals including humans. Some bacteria live in the soil or
on dead plant matter where they play an important role in the cycling of nutrients. Some types
cause food spoilage and crop damage but others are incredibly useful in the production of
fermented foods such as yoghurt and soy sauce. Relatively few bacteria are parasites or pathogens
that cause disease in animals and plants.
What are archaea and where the live
Archaea are a domain of single-celled microorganisms. They have no cell nucleus or any other
organelles inside their cells Like bacteria, however, archaea are prokaryotes that share certain
characteristics with bacteria such as similar size and simplicity of structure but radically different in
molecular Organisms in this domain might share some characteristics with both bacteria and
eukaryotes. They have an membrane-less nucleus like bacteria but share some genes, metabolic
pathways, and enzymes that are also observed in eukaryotes.
Many archaea have been found living in extreme environments, for example at high pressures, salt
concentrations or temperatures. These types of organisms are called extremophiles. Their cell wall
differs in structure from that of bacteria and is thought to be more stable in extreme conditions,
helping to explain why some archaea can live in many of the most hostile environments on Earth.
What are eukaryotes and where do the live?
Eukaryote refers to any of the single-celled or multicellular organisms whose cell contains a distinct,
membrane-bound nucleus. Organisms such as animals, plants, fungi, and protists are examples of
eukaryotes because their cells are organized into compartmentalized structures called organelles,
such as the nucleus. Eukaryotic cells are found in plants, animals, fungi, and protists.
The tree of life
The tree of life or universal tree of life is a metaphor, model and research tool used to explore the
evolution of life and describe the relationships between organisms, both living and extinct
,This phylogenetic tree is based on comparisons of ribosomal RNA base sequences among living
organisms. The tree divides all organisms into three domains: Bacteria, Archaea, and Eukarya.
Humans and other animals belong to the Eukarya domain. From this tree, organisms that make up
the domain Eukarya appear to have shared a more recent common ancestor with Archaea than
Bacteria.
Biological classification is the process by which scientists group living organisms. Organisms are
classified based on how similar they are. Historically, similarity was determined by examining the
physical characteristics of an organism but modern classification uses a variety of techniques
including genetic analysis.
Organisms are classified according to a system of seven ranks:
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
Kingdom
The Kingdom is the topmost of the main divisions/ranks used in biological classification of organisms.
Many scientists recognise five kingdoms in which all life on earth is divided:
Animalia, Plantae, Fungi, Protista, Prokaryota/Monera
Phylum
Phylum is one of the seven taxonomic ranks used to classify living organisms. Phylum is positioned
after Kingdom. Phyla represent the largest generally accepted groupings of animals and other living
things with certain evolutionary traits, Informally, phyla can be thought of as grouping animals based
on general body plan
Class
Class is one of the seven taxonomic ranks used to classify living organisms. Class is positioned after
Phylum and before Order. In the class, organisms are least similar to one another.
Order
Order is one of the seven taxonomic ranks used to classify living organisms. Order is positioned after
Class and before Family. comprised of families sharing a set of similar nature or character.
Family
Family is one of the seven taxonomic ranks used to classify living organisms. Family is positioned
after Order and before Genus.
Genus
Genus is one of the seven taxonomic ranks used to classify living organisms. Genus is positioned
after Family and before Species. A genus is a group of species that are closely related through
common decent.
Species
Species is one of the seven taxonomic ranks used to classify living organisms. A species can be
defined as a group of organisms that can breed and produce fertile offspring.
Who created the binomial system
, Carl Linnaeus, the father of modern taxonomy and methods of classification, was the one who
formalized the binomial nomenclature as the modern system of naming organisms . He designed the
system so as to differentiate species from one to the other Carl Linnaeus became aware of the
limitations of the plant naming system which was currently in use. The names were based on the
physical characteristics of the plants and were long and unwieldy. Linnaeus developed a simple two-
part naming system in 1735 . The first part of the name indicates the group to which the particular
plant belongs (now known as the genus), and the second part indicates the species
Binomial naming system
The binomial naming system is the system used to name species. Each species is given a name that
consists of two parts. The first part is the Genus to which the species belongs and the second part is
the species name.
For example, the honey bee (Apis mollifier) would be classified in the following way:
Kingdom = Animalia
Phylum = Arthropoda
Class = Insecta
Order = Hymenoptera
Family = Apidae
Genus = Apis
Species = Apis mellifera
Species names are always written including the Genus in either full or abbreviated, for example, Apis
mellifera or A. mellifera respectively.
Why do we think we categorised microorganism?
It will allow identification and comparison of organisms based upon the recognised
characteristics and show how closely related organisms are, allowing for evolution
Fungi classification
Fungus is a eukaryotic cell. It can either be very complex celled or simple multicellular organisms.
They are found in just about any habitat which includes land, water, air and even plants and animals.
They are classified in their own kingdom meaning that they are not animal, plants or Bacteria. The
can not make food on there on meaning that they are herorophic and plays an important role in the
ecosystem
Roles of Fungi
Food - fungi are used as food such as mushrooms and truffles. Yeast, a type of fungi, is used to
ferment alcohol or to help bread rise.
Decomposition - Fungi is a important role in the decomposition of organic matter by breaking down
organic matter releasing nitrogen, carbon and oxygen back into the soil and atmosphere.
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