<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
<span>Firstly, it is the only substance on Earth that is in liquid form at the temperatures commonly found on the Surface of our planet. Secondly, it is a superb solvent, meaning that other substances regularly and easily dissolve into it. This allows water to carry nutrients to cells, and carry waste away from them.</span>
1. Polymer refers to a lengthened, chain-like molecule comprising repeated units associated end to end.
2. Ceramic refers to a hard, brittle, corrosion and heat tolerant substance formed by administering a non-metallic mixture of minerals to intense heat.
3. Thermoset refers to the plastics, which exhibit low elongations and cannot get recycled again.
4. Thermoplastic refers to the plastics, which exhibit high elongations and can be recycled.
5. Crystal refers to the solid form originating from the organization of ions, atoms, or molecules in precise patterns of geometry.
6. Composite refers to a carbon fiber entrenched in a polymer resin matrix.
Answer:
hydrogen bond
Explanation:
by weak electrical attraction between two polar molecule hydrogen bond is developed between them
the example is water molecule in case of water two water molecules are attracted toward each other by strong hydrogen bond which is developed between highly electronegative oxygen of one water and electropositive hydrogen of another water molecule
But this rule rule is applicable only for double stranded DNA molecule. The possibility of Adenine=40% and Thymine=60% is only in single stranded DNA molecule. In the question, the DNA sample referred is a single stranded DNA. hope it helps :D
