Viral Diseases: Structure: Viral diseases are often associated as non-living as they do not move and remain outside the host cell. They consist of strands of nucleic acids, made of DNA or RNA, which are surrounded by the capsid, a protective protein layer. Viral diseases may also have a tail that helps them move. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay - How they grow/reproduce - Impacts of different environmental conditions on their growth/reproduction Example 1- Canine Parvovirus (CPV) Canine parvovirus virus is shed in the feces of infected dogs within 4-5 days of exposure to the virus , for the entire period of the disease and for 10 days after clinical recovery. Symptoms: Symptoms often associated with CPV include lethargy, signs of depression, and loss of appetite. After the appearance of these symptoms, they are followed by the appearance of high fever, vomiting and diarrhea, which is more severe in puppies. Transmission: The disease is transmitted through nasal or oral contact with a contaminated host or object such as the environment, personnel, equipment, materials and feces. Function: Once inside the dog, CPV uses rapidly dividing cells to successfully cause disease. Viruses are carried by lymphocytes in the bloodstream, so they are protected by host defenses. Once the virus enters the bloodstream, it begins to target rapidly dividing cells, hitting the bone marrow and cells lining the walls of the small intestine hardest. Example 2 - Cat flu Cat flu, known as cat flu, is a disease that affects the respiratory tract. Once introduced into the respiratory system, influenza attaches and replicates in epithelial cells. The virus replicates in both the upper and lower respiratory systems. Symptoms Symptoms associated with cat flu include the cat appearing lethargic, depressed, high fever, lack of appetite, and discharge from the eyes and nose. These symptoms usually appear within 1 to 3 days of transmission of the virus. Transmission: The virus is transmitted through an infected cat. The virus is transmitted through coughs and sneezes from the infected cat, which release the virus into the air, meaning direct physical contact is not required. However, through direct physical contact with an infected cat, the virus can lead to an infection. Function: Once influenza is introduced into the respiratory system, it attaches to and replicates in epithelial cells. The virus replicates in both the upper and lower respiratory systems. Viral replication combined with immune responses to infection results in the destruction and loss of cells lining the respiratory system. When the virus infects respiratory epithelial cells, it is detected by receptors. These receptors produce and activate antiviral responses. However, the virus can escape these antiviral responses using NS1 (non-structural protein that blocks the production of antiviral responses – interferon synthesis). This allows the virus to overcome the cats' defense systems. Bacterial disease: -Structure -How they grow/reproduce -impacts of different environmental conditions on their growth/reproductionExample 1- Salmonella Salmonella is a type of bacteria that affects the stomach and intestines by attacking causing food poisoning. Symptoms: Symptoms associated with salmonella include diarrhea, vomiting, and also cause abdominal pain 12 to 72 hours after the infection occurs. Transmission: Salmonella is transmitted through the ingestion of food.