the simplest living things
TRANSCRIPT
The Monera Kingdom contains microscopic, unicellular, prokaryotic organisms.
Bacteria belong to the Monera Kingdom.
Bacteria Nutrition
Most bacteria are heterotrophs:
Parasites: feed off living things. They produce illeness like tuberculosis.
Saprophytes: live on dead or
decomposing matter. Some of them are useful: lactobacilo is used to make yoghurt.
Symbionts: live on the bodies of
other living things to provide mutual benefit. For ex. Intestinal bacteria.
Bacteria Reproduction
Bacteria reproduce by binary fission, producing two daughter cells. Each daughter cell divides again.
Bacteria Interaction with the Environment
When living conditions are unfavourable, some bacteria can produce a thick wall around their body, and become a “resistance spore”.
So, they can stand very low and high temperatures, dry seasons, etc.
Activity 2. Test yourself!
Are these statements true or false?
1. Monera Kingdom includes animals and fungi. 2. Bacteria have prokaryotic cells. 3. Most bacteria are autotrophs. 4. Bacteria have capsule, cell wall and cell
membrane. 5. Bacteria are classified by shape into four groups. 6. Bacillus are round. 7. Parasites live on dead matter. 8. Cyanobacteria produce illeness. 9. Bacteria are divided by binary fission.
Protoctist Kingdom includes unicellular and multicellular living things. They are eukaryotes, and have no tissues.
Protozoa and Algae are found in this kingdom.
PROTOZOA
They are:
Unicellular.
Heterotrophs: they feed on bacteria, organic remains, and other microscopic organisms.
Aquatic, and they live in both salt water and fresh water.
Some of them float on water (forming Zooplankton) and are food for animals, like blue whales.
Some of them are parasites, they live in other living things bodies, and cause illnesses.
There are four groups of Protozoa:
1) Flagellates: they move using a flagellum.
2) Cilliates: they move using cillia
(hair-like organs)
3) Rhizopods: they move using
pseudopods (projections of cell
cytoplasm).
4) Sporozoa: they have no movement. All of them a parasites. Plasmodium causes malaria.
ALGAE
They are:
Unicellular or multicellular.
Autotrophs: they contain chlorophyll and other pigments which absorb the sunlight for photosynthesis.
Some of them float on water forming Phytoplankton, and are food for animals.
There are three groups of algae, depending on the photosynthetic pigment they use:
1) Green Algae: they use chlorophyll. They live on the surface of fresh and salt water.
2) Brown Algae: they use fucoxantine. They live only in salt water. Some of them can be hundreds of metres high (Sargazos).
Activity 4. Which type of algae…
1. Uses rodophyll to absorb the sunlight?
2. Lives only in salt water?
3. Lives near the surface in salt and fresh water?
4. Uses chlorophyll to absorb the sunlight?
5. Uses fucoxantine to absorb the sunlight?
What are viruses?
Viruses are not cells, and they can not carry out the three vital functions, son they are not really living things.
They are obligate parasites: they must infect a living thing, and reproduce inside its cells.
So, viruses can not live independently of their host.
What is a virus like?
Very small: they can only be seen using an electron microscope.
Unable to move.
They can live in any habitat: in the ground, in water, and in the air.
The Virus’ Structure
Viral Envelope: it is not in all viruses.
Capsid: made up of proteins, it can be different in shape.
Nucleic Acid: genetic material inside the capsid.
Activity 5. True or false?
1. Viruses carry out the three life processes.
2. All viruses have a viral envelope.
3. Viruses can live independently of their host.
4. All virus have nucleic acids.
5. All viruses are obligate parasites.
6. All virus have a capsid made up of proteins.
They are illnesses produced by a pathogenic microorganism.
The Inacubation Period occurs when the microorganism invades the body, but we still do not perceive the symptoms.
Symptoms are the effects that a disease has on the body (for ex. Fever).
Contagion occurs when microorganisms are transmitted from a sick person to a healthy one.
Vectors are insects or other animals that carry the microorganism from one person to another. For ex. Anopheles is a mosquito that carry Plasmodium, a protozoa which causes Malaria.
Activity 6.- Look for the correct illnesses using the chart on page 79:
Through
Air Trough Water
Through Spoiled Food
Through the skin
Through sexual and
blood contact
Virus
Bacteria
Protozoa
Fungi
How can you fight Infectious Diseases?
Personal Hygiene: wash your hands before eating.
Eat and drink only fresh food and drinks.
Antibiotics: are substances produced by certain bacteria and fungi, that can kill the microorganism. It is a curative measure.
Vaccines: contain weaked microorganism. Then, our body produce the specific antibody to fight that microorganism. When the same stronger microorganism invades us, we will be protected against it. It is a preventive measure.
Some microorganisms transform dead animals and plants into inorganic substances that can be taken by plants (Decomposer Microorganisms).
Intestinal Flora are bacteria that live in animal digestive systems. They produce vitamins and take part in digestive processes.
Some bacteria are used to make food, like cheese, yoghourt or wine.
Some microorganisms are used to obtain antibiotics. Ex. Penicillium.