Answer:
A) A single base pair change.
Explanation:
Point mutation is a change in a single base pair of a nucleotide. This comes as a results of mistakes made during DNA replication, induced by ultravoilet radiations, extreme heat and X-rays. There are three types of point or substitution mutations; change, deletion and insertion. The nucleotide bases are either mistakenly inserted, changed or deleted, thus changing the resulting protein or amino acid being coded for.
<h3><u>Connective tissue:</u></h3>
It is the layer under the epithelial tissue in the body. It is stronger than epithelial tissue and is found in many organs. It provides protection.
<h3><u>Epithelial tissue:</u></h3>
It covers the outside of the body like a veil. located in the outermost part of the body. Protects the body against microbes and infections.
<h3><u>Muscle tissue:</u></h3>
It is located in the joint areas and forms the support and movement system. It allows us to make bodily movements.
<h3><u>Nervous tissue:</u></h3>
It is the fastest communication tissue. It allows us to feel pain and the sense of touch. It is impossible to repair this tissue after it is damaged. It causes paralysis. It is very important as it plays a role in the activity of neural transmission.
Answer:
Each day, Earth’s 6.3 billion people interact with the atmosphere in many ways. Jet pilots, for example, fly through the atmosphere and must be intimately familiar with weather patterns. Satellite TV stations send signals through the atmosphere that bounce off satellites and then back through the atmosphere to satellite dishes scattered far and wide. Many of these interactions are invisible and involve gases, heat, or energy waves. The most basic of these interactions is, of course, breathing. In fact, right now as you read these words, you are inhaling oxygen (O2) and exhaling carbon dioxide (CO2). We humans need a steady supply of “clean” air.
Explanation:
Woof that took forever
There
The geosphere affects the atmosphere as soil provides nutrients to plants that then release water vapor into the atmosphere. Furthermore, how do the spheres interact? The 4 spheres are: lithosphere (land), hydrosphere (water), atmosphere (air) and biosphere (living things). All the spheres interact with other spheres. River action erodes banks (lithosphere) and uproots plants (biosphere) on the riverbanks.
Based on the CDC guidelines a person with a CD4+ cell count between 200-400 is regarded as being in <u>the second stage</u> of the HIV infection.
Acquired Immunodeficiency Syndrome
Acquired immunodeficiency syndrome (AIDS) is a condition caused by HIV (human immunodeficiency virus). AIDS is a chronic disorder and can become life-threatening for the infected person. The HIV viruses reproduce inside the host and while doing so they destroy the CD4+ immune cells which reduce the person's ability to fight against other diseases.
CD4+ cell count and AIDS
According to the CDC (U.S. Centers for Disease Control and Prevention), HIV infection is categorized into different stages based on the number of CD4+ cells.
- Stage 1: - CD4+ cell count is more than 500 per microlitre. There are no symptoms or AIDS-related conditions.
- Stage 2: - CD4+ cell count is more than 500 per microlitre. There are no symptoms or AIDS-related conditions.
- Stage 3: - The CD4+ cell count falls below 200 and AIDS-related symptoms and conditions are present.
Learn more about HIV infection here:
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