PP1 Diversity change and continuity micro organisms

KNOWLEDGE AREA: Diversity, change and continuity TOPIC 1: Biodiversity and Classification of Micro-organisms Biodiversity

Review of Five Kingdom Classification System Viruses Bacteria Protista Fungi

Organism are grouped into 5 kingdoms according to certain common characteristics. KINGDOM MONERA: consists of all those organisms that are prokaryotes. KINGDOM PROTISTA: these are eukaryotes that are unicellular. KINGDOM PLANTAE: these are eukaryotes that are multi-cellular and are autotrophic. KINGDOM FUNGI: these are eukaryotic, multi - cellular, heterotrophic organisms that digests their food before taken them in. KINGDOM ANIMALIA: are eukaryotic, multi-cellular, heterotrophic organisms that take in their food before digesting them.

Structures that can be seen with the naked eye are called macroscopic. Structures that are only visible with the microscope are called microscopic. Some organisms are so tiny that they can only be viewed under the microscope, these organisms are called micro-organisms. Micro-organisms occur in all five kingdoms. There is a sixth group for organisms that cannot be placed into any of the 5 kingdoms. These micro-organisms are called viruses.

CLASSIFICATION: Viruses do not belong to any one of the 5 kingdoms because they have characteristics of both living and non - living organisms. Viruses are considered to be living, because they undergo reproduction when they are within cells of a living organisms.

Viruses are non-living: 1. They can not respire. 2. They can not reproduce on their own. 3. They form crystals and can survive in this form for many years.

STRUCTURE: Viruses are microscopic as mentioned earlier. They are smaller than bacteria and ribosomes. Most viruses are only visible under the electron microscope. They have a regular shape, or can be spherical, spiral or rod-like. Some have tails to help in attaching them to the host cell.

VIRUSES: STRUCTURES Membranous (a)Tobacco (b) Adenoviruses (c)influenza viruses (d)Bacteriophage T4 mosaic virus Copyright © Pearson Education, inc.. publishing as Benjamin Cummings.

The virus has an outer coat, called the protein coat. Within the protein coat there is a central nucleic acid core. The nucleic acid core maybe either DNA or RNA. Viruses that attack animals have a nucleic acid core of either DNA or RNA.

Those viruses that attack plants or bacteria have a nucleic acid core of RNA. A virus that attacks a bacteria is called bacteriophage.

Viruses do not have any other cell structures. For example there is no vacuoles and mitochondria. Therefore viruses are said to be a-cellular or non-cellular.

GENERAL CHARACTERISTICS OF THE VIRUS: All viruses are parasitic. Viruses are absolutely specific. This means that a particular virus will only live in a particular host and nowhere else. For example the mumps virus is only found in the salivary glands of a human.

Virus cause diseases. Some examples of diseases in humans that are caused by viruses are: mumps, measles, AIDS, common cold and small pox. Viruses are able to reproduce by converting the hosts nucleic acid to the viral nucleic acid.

LOCATION and CHARACTERISTICS: Bacteria occur in the air, water and soil. They thrive in areas that are moist and damp. The optimum temperature for bacteria to grow and reproduce is between 30⁰C and 37⁰C. They can survive at extremes of temperatures ranging from -18⁰C to 70⁰C. Some bacteria require oxygen to survive. These bacteria are called aerobic bacteria. Some bacteria do not require oxygen to survive. These bacteria are called anaerobic bacteria.

BACTERIA: STRUCTURE

STRUCTURE: Bacteria are living organisms. They are the smallest living organisms. They are microscopic and unicellular. They can occur in 1 of 4 shapes: coccus, bacillus, spirillum and vibro.

Each bacterium has the following general structure: They are surrounded on the on outside by a slime capsule. The slime capsule prevents the bacterium form drying out. Below the slime capsule is the cell wall. The cell wall is made up of 3 compounds: polysaccharides, proteins and lipids.

Some bacteria have these long whip-like structures called flagella. The flagella are used for locomotion. The cell membrane lies within the cell wall. The cell membrane is called the plasmalemma. The plasmalemma encloses the cytoplasm.

The nuclear material is embedded in the centre of the cytoplasm. The nuclear material is the chromatin network, but it is not bound by any nuclear membrane. Therefore the bacteria is a prokaryote. This area is called the nucleoid. Ribosomes are also found in the cytoplasm.

GENERAL CHARACTERISTICS: Bacteria may be autotrophic or heterotrophic. There are 2 types of autotrophic bacteria. They are photosynthetic bacteria and chemosynthetic bacteria. The photosynthetic bacteria make their own food using sunlight. Chemosynthetic bacteria also make their own food, but the energy need is obtained from chemical processes.

There are 3 types of heterotrophic bacteria: parasitic bacteria, saprophytic bacteria and mutualistic bacteria. The parasitic bacteria obtain their food from the living organisms on which they live. They cause harm to these living organisms. If the parasitic bacteria cause diseases they are called pathogens. If they do not cause disease then they are called non-pathogens. The mutualistic bacteria have a close relationship with another organism in which they both benefit. The saprophytic bacteria obtain their food from dead and decaying matter. This makes them very important in the nitrogen cycle and as decomposers.

These are eukaryotes. They do not fit into the any of the other 4 kingdoms. Slime moulds, protozoans, diatoms, red, brown and green algae are examples of protists.

The organism that belong to this kingdom do not have the same basic structure. They show a great deal of diversity in their structure. Some of them are unicellular and microscopic. Others are multicellular and macroscopic, for example seaweeds. Protozoans are a group of protists that are animal like and are able to move, like the Amoeba and Euglena. They have pseudopodia or flagella to enable them to move.

Others are plant like and cannot move, like the sea weed. Those that have flagella show differences too. The flagella of the dinoflagellates are arranged in many patterns. Their shape and structure also vary greatly. Spirogyra are made up of long, thin filaments while the Chlorella are unicellular. The diatoms look like microscopic, glass-like ornaments. The slime moulds look like fungi. Some have chloroplast (Euglena and Spirogyra) and others do not.

GENERAL CHARACTERISTICS: Most are aquatic while others are terrestrial found living in damp soil or snow. They have both autotrophic and heterotrophic organisms. There are different types of heterotrophic protists as well. Some of them are parasitic e.g. Entamobea histolytica and others are free living. The slime moulds engulf their food by a process called phagocytosis.

Phagocytosis is the process during which food is engulfed by the pseudopodia together with droplet of water to form a food vacuole. Asexual reproduction by binary fission occurs. During binary fission one cell divides to form two. In other lifecycles both sexual and asexual reproduction occurs.

Mushrooms, yeast, ringworms and the moulds found on bread are examples of fungi. GENERAL STRUCTURE OF FUNGI: Like the Protista, all fungi do not have the same structure. They all show the following basic structure. 1. Fungi are similar to plants because they all have cell walls.

2. However they are all unlike plants, they do not have chloroplasts. Therefore they are unable to make their own food. They are therefore heterotrophic. 3. They all reproduce by spores. 4. Their spores are produced in different parts of the fungus. For example: the bread mould spores are produced in spore cases called the sporangiophore, while the mushroom spores are produced in club- shaped structures. These structures are found within the cap of the mushroom. The cap is the fruiting body and still the Penicillium produce spores in a sac-like structures.

5. The fungi are heterotrophic, but they all obtain their food differently. 6. Some are parasites, since they depend on other living organisms for food. 7. Others are saprophytic, they feed on dead and decaying matter. 8. Some are unicellular like the yeast. 9. Most are multicellular.

The structure of the bread mould: Since the bread mould does not have true roots, stems and leaves it is called a thallus. The mould looks like a tangled mass of thread-like structure called the mycelium.

Each threadlike structure is called hyphae. There are 3 types of hyphae : 1. Rhizoids - these are root-like hyphae that penetrate the bread. 2. Stolons - these creep over the surface of the bread. 3. Sporangiophores - these are upright hyphae and they end in structures that carries spores.

A culture is a growth, of in this case, of micro-organisms. When handling pathogenic cultures it is not possible for us to see whether the micro-organism is pathogenic or not because they cannot be seen with the naked eye. Therefore we should take the following precautions: 1. Do not touch the culture unless you are asked to do so by your teacher (safe to touch). 2. Wear gloves when handling these cultures.

3. Do not inhale deeply or sneeze near the culture. If you inhale to deeply you might inhale some of the spores and you might get infected with the micro organism. If you sneeze you might blow the spore towards your classmates. 4. If the culture spills on to any part of your body, wash thoroughly with running water and tell you teacher. 5. When your are done with the culture, remove and wash your gloves.

Agar is a jelly-like substance that comes from certain marine algae. It is used as a base on which micro-organisms are cultured. An agar plate is a petri dish that has agar on it, other nutrients are added to it.

The agar together with the nutrients serve as a growth medium for micro-organisms. There are many types of agar plates. Some agar plates grow certain types of bacteria and not others. At school we use nutrient agar plates because these plates do not selectively grow pathogenic bacteria. Therefore it is safer to use.

Kingdom Monera: consists of all those organisms that are prokaryotes. Prokaryotes: are those organisms that do not have true nuclei. Kingdom Protista: these are eukaryotes that are unicellular. Eukaryotes: are organisms that have true nuclei. Kingdom Plantae: these are eukaryotes that are multicellular and are autotrophic.

Unicellular: are organisms that are made up of one cell only. Multicellular: are organisms that are made up of more than one cell only. Autotrophic: are organisms that are able to manufacture their own food. Heterotrophic: are those organisms that are unable to manufacture their own food. Kingdom Fungi: these are eukaryotic, multicellular, heterotrophic organisms that digests their food before taken them in.

Macroscopic structures: are structure that can be seen with the naked eye. Microscopic structures: are those that are only visible with the microscope. Micro-organisms: are tiny organisms that can only be viewed under the microscope. Symmetrical: is when an organism can be cut into two identical halves. Acellular structures: are those that are not considered to be cells because they do not have any cell structure.

Bacteriophage: is a virus that attacks a bacteria. Aerobic bacteria: live in the presence of oxygen. Anaerobic bacteria: can live in the absence of oxygen. Flagella: are the long whip-like structures that are used for locomotion. Nucleoid: is the area within the bacteria that contains nuclear material. Aquatic organisms: are those that live in water. Terrestrial organisms: are those that live on land. Phagocytosis: is the process during which food is engulfed by the pseudopodia together with droplet of water to form a food vacuole.

Mycelium: is a tangled mass of thread-like structures. Hyphae: is each threadlike structure in a mycelium. Thallus: is an organism that does not have true roots, stems and leaves. Rhizoids: these are root-like hyphae that penetrate the bread. Stolons: these creep over the surface of the bread. Sporangiophores: these are upright hyphae and they end in sporangiophores, that carries spores. Agar: is a jelly-like substance that comes from certain marine algae. Agar plate: is a petri dish that has agar on it, then other nutrients are added to it.

The kingdom that has all the prokaryotes is. A. Monera B. Protista C. Plantae D. Fungi

The kingdom that is made up of organisms that digest their food before taking it in is… A. Monera B. Protista C. Animalia D. Fungi

The kingdom that contains all the autotrophic organisms is… A. Monera B. Protista C. Plantae D. Fungi

The kingdom that is made up of eukaryotic, unicellular organism is… A. Monera B. Protista C. Plantae D. Fungi

The micro-organism that is both living and non-living is… A. Bacteria B. Virus C. Fungi D. Protista

All heterotrophic, eukaryotic organisms belong to the Kingdom… A. Monera B. Protista C. Animalia D. Fungi

The smallest living micro-organism is… A. Bacteria B. Virus C. Fungi D. Protista

Small pox is a disease that is caused by… A. Bacteria B. Virus C. Fungi D. Protista

The organism that is able to reproduce by converting the host’s nuclei to its own… A. Bacteria B. Virus C. Fungi D. Protista

Unicellular, prokaryotic organism with cell walls and flagella… A. Bacteria B. Virus C. Fungi D. Protista

Diatoms, Spirogyra and seaweed are examples of… A. Bacteria B. Virus C. Fungi D. Protista

The jelly-like material derived from seaweeds is called… A. Agar B. Diatoms C. Seaweeds D. None of the above

The rod-like shape of the bacteria is… A. Coccus B. Spirilum C. Bacillus D. Vibro

The area of the cytoplasm in bacteria that contain nuclear material. A. Nucleoid B. Nucleus C. Nucleolus D. Chromatin network

The outer coat of the virus is called… A. Plasma lemma B. Cell wall C. Cell membrane D. Protein coat

The root like hyphae of the bread mould is A. Rhizoids B. Stolon C. Sporangiophore D. Mycelium

Collective name given to the tangled mass of thread- like structures in the bread mould is… A. Rhizoids B. Stolon C. Sporangiophore D. Mycelium

The upright hyphae of the bread mould is… A. Rhizoids B. Stolon C. Sporangiophore D. Mycelium

Since the bread mould does not have true root, stems and leaves it is called a… A. Rhizoids B. Thallus C. Sporangiophore D. Mycelium

The horizontal hyhpae, found on the surface of the bread in the bread mould is… A. Rhizoids B. Stolon C. Sporangiophore D. Mycelium

1. A 2. D 3. C 4. B 5. B 6. C 7. A 8. B 9. B 10. A

11. D 12. A 13. C 14. A 15. D 16. A 17. D 18. C 19. B 20. B