<em>A </em><em>virus </em><em>is an agent that causes infections and diseases.
</em>
<h2>Further Explanation
</h2>
Viruses are microscopic parasites that infect cells of biological organisms. Viruses are obligate parasites, this is because viruses can only reproduce in living material by invading and utilizing the cells of living things because viruses do not have cellular equipment to reproduce themselves.
The term virus usually refers to particles that infect eukaryote cells (multicellular organisms and many types of single-cell organisms), while the term bacteriophage or phage is used for types that attack types of prokaryotic cells (bacteria and other organisms that do not cell nucleated).
The virus has been infecting since the days before Christ, this is evidenced by the existence of several discoveries, namely reports of virus infections in hieroglyphics in Memphis, the capital of ancient Egypt (1400 BC) which shows the existence of poliomyelitis. In addition, King Pharaoh Ramses V died in 1196 BC and is believed to have died of the smallpox virus.
In 1880, Louis Pasteur and Robert Koch put forward a "germ theory" namely that microorganisms are the cause of disease. At that time also the famous Koch Postulate which is very well known today, namely:
- A disease agent must be present in every case of the disease
- The agent must be isolated from the host and can be grown in vitro
- When the muri agent culture is inoculated into susceptible healthy host cells, it can cause disease
- The same agent can be taken and re-isolated from the infected host
<h3>Various kinds of viral infections
</h3>
- Acute infections are infections that last for a short time but can also be fatal.
- Chronic infection is a prolonged viral infection so there is a risk of symptoms of the disease coming back.
Learn More
Viruses brainly.com/question/11690598
The infection by virus brainly.com/question/8633233
Details
Class: Middle School
Subject: Biology
Keywords: viruses, disease, infection
Answer:
Structurally, plant and animal cells are very similar because they are both eukaryotic cells. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes. Both also contain similar membranes, cytosol, and cytoskeletal elements.
Explanation:
<span>The major effects of insulin on muscle and adipose tissue are: (1) Carbohydrate metabolism: (a) it increases the rate of glucose transport across the cell membrane, (b) it increases the rate of glycolysis by increasing hexokinase and 6-phosphofructokinase activity, (c) it stimulates the rate of glycogen synthesis and decreases the rate of glycogen breakdown. (2) Lipid metabolism: (a) it decreases the rate of lipolysis in adipose tissue and hence lowers the plasma fatty acid level, (b) it stimulates fatty acid and triacylglycerol synthesis in tissues, (c) it increases the uptake of triglycerides from the blood into adipose tissue and muscle, (d) it decreases the rate of fatty acid oxidation in muscle and liver. (3) Protein metabolism: (a) it increases the rate of transport of some amino acids into tissues, (b) it increases the rate of protein synthesis in muscle, adipose tissue, liver, and other tissues, (c) it decreases the rate of protein degradation in muscle (and perhaps other tissues). These insulin effects serve to encourage the synthesis of carbohydrate, fat and protein, therefore, insulin can be considered to be an anabolic hormone.
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
</span>
<span>Based on the mentioned symptoms, the disorder that best describes his condition is Spontaneous pneumothorax and surgery is needed in order to overcome it. The presence of air in the form of small packs between the lungs and chest is a formal way of describing this condition and this may lead to damage in the lungs.</span>