Gcse /Igcse biology 2-Communicable disease

A communicable disease is one that is spread from one person to another through a variety of ways that include: contact with blood and bodily fluids; breathing in an airborne virus; or by being bitten by an insect.

A communicable disease is a disease that spreads from one person or animal to another. Pathogens such as viruses, bacteria, and fungi cause these diseases.

There are four main types of pathogens cause infection:

Viruses, bacteria, fungi, and Protists.

Viruses

Viruses are tiny pathogens that contain genetic material. Unlike other pathogens, they lack the complex structure of a cell.

To replicate, they must enter the cells of other living beings. Once inside, they use the cell’s machinery to make copies of themselves.

Bacteria

Bacteria are microscopic, single-celled organisms. They exist in almost every environment on earth, including inside the human body.

Many bacteria are harmless, and some help the body to function. However, bacteria can also cause infections that damage the body.

Fungi

Fungi are a type of organism that includes yeasts, molds, and mushrooms. There are millionsTrusted Source of different fungi. However, only around 300 cause harmful illnesses.

Fungal infections can occur anywhere in the body. However, they commonly affect the skin and mucus membranes.

Protists

Protists are microscopic organisms that typically consist of a single cell.

Some Protists are parasitic, meaning they live on or inside another organism and use the organism’s nutrients for their own survival. Parasitic Protists can cause various diseases.