<em>A </em><em>virus </em><em>is an agent that causes infections and diseases.
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<h2>Further Explanation
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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
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- 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
P<span>ituitary hormones:
1. Act on breasts to induce milk production.
2. Make you sweat.
3. Can cause weight gain.
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Answer: in the atom you can find: electrons and protons
Explanation:
You can find electrons in an atom because it is the negative energy that rounds the atom on the outside’s part.
Then, the protons are the positive energy that is on the atom’s inside.
Both of the energies are fused and it end on a neutron energy.
Answer: Fertilization in plants occurs after pollination and germination. Pollination occurs through the transfer of pollen which is the male microgametes of seed plants, producing the sperm – from one plant to the stigma (the female reproductive organ) of another.
Explanation:
The answer is an aminoacyl-tRNA synthetase.
<span> The aminoacyl-tRNA synthetase is an enzyme responsible for the attachment of an amino acid to tRNA. First, it binds the ATP and the amino acid which results in aminoacyl-AMP and inorganic pyrophosphate. Aminoacyl-AMP binds the appropriate tRNA molecule. The aminoacyl group dissociates from the complex with AMP and binds the tRNA molecule creating aminoacyl-tRNA.</span>
