ANAS AL-ALIMI
Assignment UNIT 12 A BIOLOGY DISEASES AND INFECTION
⮚ LEARNING AIM: Investigate different diseases and infections that can
affect human.
ASSIGNMENT
, ANAS AL-ALIMI
Explanation of the characteristics of the five main pathogenic organisms linked to a
disease caused by each.
Microorganisms are microscopic organisms that are too small for the human eye to see, such as
bacteria, viruses, fungi, protozoa, and algae. They are the most numerous organisms on the planet
and play an important part in the environment and the lives of all living beings.
Microorganisms come in different shapes and sizes, from single-celled organisms to complicated
multicellular organisms. r A microorganism's structure is determined by its kind. Bacteria, for
example, are single-celled organisms with a cell wall, nucleus, and a variety of organelles. Viruses, on
the other hand, are made up of genetic material encased in a protein sheath. Fungi are fungi.
Bacteria
Bacteria are single-celled organisms that appear in millions and millions. They exist inside and
outside of different organisms. Most bacteria are innocuous, and some are beneficial, but a few are
dangerous. All types of Bacteria are prokaryotes, that means they do not have a nucleus or few
other organelles. Most bacteria, on the other hand, have a cell wall that surrounds and protects the
cell membrane. Bacteria come in different shapes. They have a high reproductive rate and can thrive
in harsh conditions such as acidic hot springs and Antarctic ice. Bacteria are also categorised based
on their metabolic activities, which include photosynthesis, respiration, and fermentation.
Structure of bacteria Cell Wall: The cell wall is a hard layer that surrounds and shapes
the cell. It is made up of peptidoglycan. Peptidoglycan is made of
amino acids.
The plasma membrane is a thin layer of lipids and proteins that
surrounds the cell and functions as a barrier to the outside world.
Ribosomes are tiny organelles that oversee protein synthesis.
Flagella are long. They are responsible for bacterial movement.
Pili are small, hair-like structures that bacteria can use to cling to
surfaces. They are made up of a protein known as pilin.
The capsule’s function protects the cell from dehydration and
predation.
Cytoplasm where chemical reactions take place.
The nucleoid is a region of the cytoplasm that houses the bacterial
chromosome. It is not encased by a membrane.
Characteristics of They are unicellular.
bacteria
They have no membrane bound organelles.
Their cell wall is made of peptidoglycan.
They are about 0.2-2μm in diameter and 1-8μm in duration
Forms and shape of Cocci are spherical bacteria that often exist in pairs, chains, or clusters.
bacteria Staphylococcus, Streptococcus, and Neisseria are examples of cocci.
Bacilli are rod-shaped bacteria that often exist in pairs or chains. Bacillus
and Listeria are two examples of bacilli.
Spirilla: Spirilla are spiral-shaped bacteria found in long, curved chains.
Vibrio and Spirillum are examples of spirilla.