Biodiversity and Classification of Microorganisms
- Organisms that are too small to see with a naked eye
- Some organisms cause diseases (Pathogens)
- They are important for medicine and health
Viruses
- Different modes of transfer
- Nonliving
- Dependent on the host cell
- Cannot replicate outside the host
- Antigens: Antibodies
- Infects the host cell and uses it to replicate
- Living organisms display the 7 life processes: MRSGREN
● Movement
● Respiration
● Sensitivity to growth
● Growth
● Reproduction
● Excretion
● Nutrition
- Common Viruses:
● Hepatitis A, B,C
● Measles, mumps, and rubella
● Polio
● Rabies
● Influenza
● HIV
● Covid-19 (CoronaVirus)
Bacteria
- Prokaryotes:are organisms that consist of a single prokaryotic cell. Eukaryotic
cells are found in plants, animals, fungi, and protists Pro = before & Karyote =
Nucleus
- Primitive → These cells usually live in extreme environments. They have no
nucleus and have unused sections of genes.
- Various shapes
- Living organisms (display the 7 processes of life)
- exponential growth
- Unicellular because DNA is not contained, when DNA replicates bacteria mutates
easily.
- Bacteria is needed in the Colon as it is essential for health
- Some bacteria cause pathogens (pathogenic bacteria) and need to be treated with
antibiotics.
- Bacterial infection examples:
● E-coli - Escherichia Coli
● Strep throat
● Middle - ear infection
, ● UTI
● TB
● Pneumonia
● Cholera
Other microorganisms - Fungi
- Mycologist studies Fungi
- Unicellular (microscopic) & multicellular (macroscopic)
- Decomposes organic material (ecosystem service)
- Organic: Living organisms: Plants and animals
- Inorganic: Elements: Water, rocks, wind, fire
- Synthetic: Man-made
- Heterotroph: need food
- Unicellular Fungi reproduce asexually (yeast)
- Human Fungal Diseases: Athletes foot, yeast infection (unicellular)
- Benefits derived from Fungi: Medicine (Penicillin which is an Antibiotic)
Protists: are a diverse collection of organisms. While exceptions exist, they are
primarily microscopic and unicellular, or made up of a single cell. The cells of protists
are highly organized with a nucleus and specialized cellular machinery called
organelles.
- Kingdom Protista
- Eukaryotes: not plant or animal
- Most harmful: Plasmodium - lives in female mosquitoes and causes malaria
- Plasmodium → Parasite → Mosquito (host)
- Amoeba - is a type of cell or unicellular organism which has the ability to alter
its shape
- Phagocytosis: one cell engulfs another cell
Epidemiology/disease management: the branch of medicine which deals with the incidence,
distribution, and possible control of diseases and other factors relating to health.
- Infectious diseases / communicable diseases cause an epidemic. For example;
Covid - 19
- It has a bell-shaped curve
- If an organism spreads a pathogen then the organism is called the vector/host of
diseases
- NHLS: National Health Laboratory Services deal with diseases in South Africa.
Herd Immunity/treatments:
- Vaccinated means immune / inoculated
- The more people who are immune the lower the infection rate
- Fewer positive cases = overall epidemic is over
- Hospitals are less burdened
,Plant reproduction
● Plant reproduction is the production of new offspring in plants, which can be
accomplished by sexual or asexual reproduction.
● Fertilised ovules develop into seeds and the ovary into fruit.
● That sexual reproduction is used in the production of new and improved varieties of
food crops including polyploidy
Asexual reproduction in plants: (vegatative reproduction)
● Offspring formed from asexual reproduction are genetically identical to the parent.
● Does not involve sex cells
● Reproduction without the formation of gametes (sex cells).
Asexual reproduction by spores:
● Moss and ferns do not form seeds
● They produce asexually by producing spores - spores are produced by sexual
reproduction: a sperm cell swims to the eggs and forms sporophytes which then
releases the spores. If the spores land in favourable conditions they will germinate
into new plants
● Spores germinate into gametophytes plants
● When a gametophyte matures it produces gametes, sexual reproduction occurs
Asexual reproduction in vegetative plants:
● Does not involve the male and female sex organs
● Responsible for producing new plants (clones of the parent)
Advantages of asexual reproduction in plants:
● Only one plant is needed
● offspring are genetically alike, if the parents are as well adapted to the environment
than the new plants will also be well adapted to the environment
● new plants are produced relatively quickly
● agents of pollination and seed dispersal are not required
● One can select a plant with desirable characteristics for example producing
beautiful flowers and create identical plants with that characteristic
Disadvantages of asexual reproduction in plants:
● A weak parent plant will produce weak offspring since they are genetically alike
● If there are changes to the environment, new plants may not survive since all
offspring are genetically alike and equally susceptible to biotic and abiotic factors.
Similarities between asexual and sexual reproduction:
● Both forms use DNA to create new life forms
● Both have a mitosis phase.
● The offspring also have the same number of chromosomes as the original parent
cells.
, ● Both of these forms of reproduction occur in plants, fungi and animals
(parthenogenesis) however the specific form of reproduction will depend on the
species
Differences between asexual and sexual reproduction:
Functions of Male parts:
● Stamen: main flower parts
● Anther: Produce male sex cells (pollen grains)
● Filament: carry nutrients to the anther
● pollen grain: The pollen grains carry the male gametes from the anther to ovary and
the ovules.
● Gametes: the cells used during sexual reproduction to produce a new individual
organism or zygote.
Function of Female parts:
● Stigma: The top of the female part of the flower which collects pollen grains
● Style: the elongated part of a carpel that joins the ovary to the stigma. It is the tube
through which pollen is delivered to the ovary.
● Ovary: Produces the female sex cells
● Ovule: contained within the ovary, and in the event of successful pollination, they will
become the seed of the fruit.
● Seed: seed develops into flower
- Organisms that are too small to see with a naked eye
- Some organisms cause diseases (Pathogens)
- They are important for medicine and health
Viruses
- Different modes of transfer
- Nonliving
- Dependent on the host cell
- Cannot replicate outside the host
- Antigens: Antibodies
- Infects the host cell and uses it to replicate
- Living organisms display the 7 life processes: MRSGREN
● Movement
● Respiration
● Sensitivity to growth
● Growth
● Reproduction
● Excretion
● Nutrition
- Common Viruses:
● Hepatitis A, B,C
● Measles, mumps, and rubella
● Polio
● Rabies
● Influenza
● HIV
● Covid-19 (CoronaVirus)
Bacteria
- Prokaryotes:are organisms that consist of a single prokaryotic cell. Eukaryotic
cells are found in plants, animals, fungi, and protists Pro = before & Karyote =
Nucleus
- Primitive → These cells usually live in extreme environments. They have no
nucleus and have unused sections of genes.
- Various shapes
- Living organisms (display the 7 processes of life)
- exponential growth
- Unicellular because DNA is not contained, when DNA replicates bacteria mutates
easily.
- Bacteria is needed in the Colon as it is essential for health
- Some bacteria cause pathogens (pathogenic bacteria) and need to be treated with
antibiotics.
- Bacterial infection examples:
● E-coli - Escherichia Coli
● Strep throat
● Middle - ear infection
, ● UTI
● TB
● Pneumonia
● Cholera
Other microorganisms - Fungi
- Mycologist studies Fungi
- Unicellular (microscopic) & multicellular (macroscopic)
- Decomposes organic material (ecosystem service)
- Organic: Living organisms: Plants and animals
- Inorganic: Elements: Water, rocks, wind, fire
- Synthetic: Man-made
- Heterotroph: need food
- Unicellular Fungi reproduce asexually (yeast)
- Human Fungal Diseases: Athletes foot, yeast infection (unicellular)
- Benefits derived from Fungi: Medicine (Penicillin which is an Antibiotic)
Protists: are a diverse collection of organisms. While exceptions exist, they are
primarily microscopic and unicellular, or made up of a single cell. The cells of protists
are highly organized with a nucleus and specialized cellular machinery called
organelles.
- Kingdom Protista
- Eukaryotes: not plant or animal
- Most harmful: Plasmodium - lives in female mosquitoes and causes malaria
- Plasmodium → Parasite → Mosquito (host)
- Amoeba - is a type of cell or unicellular organism which has the ability to alter
its shape
- Phagocytosis: one cell engulfs another cell
Epidemiology/disease management: the branch of medicine which deals with the incidence,
distribution, and possible control of diseases and other factors relating to health.
- Infectious diseases / communicable diseases cause an epidemic. For example;
Covid - 19
- It has a bell-shaped curve
- If an organism spreads a pathogen then the organism is called the vector/host of
diseases
- NHLS: National Health Laboratory Services deal with diseases in South Africa.
Herd Immunity/treatments:
- Vaccinated means immune / inoculated
- The more people who are immune the lower the infection rate
- Fewer positive cases = overall epidemic is over
- Hospitals are less burdened
,Plant reproduction
● Plant reproduction is the production of new offspring in plants, which can be
accomplished by sexual or asexual reproduction.
● Fertilised ovules develop into seeds and the ovary into fruit.
● That sexual reproduction is used in the production of new and improved varieties of
food crops including polyploidy
Asexual reproduction in plants: (vegatative reproduction)
● Offspring formed from asexual reproduction are genetically identical to the parent.
● Does not involve sex cells
● Reproduction without the formation of gametes (sex cells).
Asexual reproduction by spores:
● Moss and ferns do not form seeds
● They produce asexually by producing spores - spores are produced by sexual
reproduction: a sperm cell swims to the eggs and forms sporophytes which then
releases the spores. If the spores land in favourable conditions they will germinate
into new plants
● Spores germinate into gametophytes plants
● When a gametophyte matures it produces gametes, sexual reproduction occurs
Asexual reproduction in vegetative plants:
● Does not involve the male and female sex organs
● Responsible for producing new plants (clones of the parent)
Advantages of asexual reproduction in plants:
● Only one plant is needed
● offspring are genetically alike, if the parents are as well adapted to the environment
than the new plants will also be well adapted to the environment
● new plants are produced relatively quickly
● agents of pollination and seed dispersal are not required
● One can select a plant with desirable characteristics for example producing
beautiful flowers and create identical plants with that characteristic
Disadvantages of asexual reproduction in plants:
● A weak parent plant will produce weak offspring since they are genetically alike
● If there are changes to the environment, new plants may not survive since all
offspring are genetically alike and equally susceptible to biotic and abiotic factors.
Similarities between asexual and sexual reproduction:
● Both forms use DNA to create new life forms
● Both have a mitosis phase.
● The offspring also have the same number of chromosomes as the original parent
cells.
, ● Both of these forms of reproduction occur in plants, fungi and animals
(parthenogenesis) however the specific form of reproduction will depend on the
species
Differences between asexual and sexual reproduction:
Functions of Male parts:
● Stamen: main flower parts
● Anther: Produce male sex cells (pollen grains)
● Filament: carry nutrients to the anther
● pollen grain: The pollen grains carry the male gametes from the anther to ovary and
the ovules.
● Gametes: the cells used during sexual reproduction to produce a new individual
organism or zygote.
Function of Female parts:
● Stigma: The top of the female part of the flower which collects pollen grains
● Style: the elongated part of a carpel that joins the ovary to the stigma. It is the tube
through which pollen is delivered to the ovary.
● Ovary: Produces the female sex cells
● Ovule: contained within the ovary, and in the event of successful pollination, they will
become the seed of the fruit.
● Seed: seed develops into flower
