Answer and Explanation:
The Huntington disease is caused by a mutation in the gene that codifies for the Huntingtin protein (Htt). The mutation produces an altered form of the protein leading to the neuron´s death in certain areas of the brain.
The Huntington disease characterizes for being,
- Hereditary, passing from generation to generation. To express the disease, a person must have been born with an altered gene.
- Autosomal, affecting men and women equally, because the mutated gene is located on an autosomal chromosome.
- Dominant, which means that by getting only one copy of the altered gene coming from any of the parents, the receiving person will express the disease. The mutation in the gene dominates over the normal gene copy.
- Expressed by heterozygosis. Most people affected by the disease are heterozygous, with a normal copy and a mutated copy.
There are just a few cases all around the world (3% approximately) in which the disease is expressed with no family history. The progenitors are not affected by the mutation. These cases are very rare and are called <u>"de-novo" mutations.</u> A new mutation is spontaneously produced and it is not inherited from any of the parentals. It consists of an increase in the number of CAG repetitions. In a normal person, the number of CAG repetitions is less than 35. When there are 40 or more repetitions it occurs the disease. But when there are between 35 and 39 repetitions, the penetrance of the disease is incomplete. This is a "gray zone". Those alleles that fall in the gray zone are unstable and might produce the HD. Individuals with these unstable alleles have a tendency to increase the number of repetitions from generation to generation until the number reaches 40 repetitions and the person expresses the disease. This <u>usually occurs in the paternal germinal line</u>, as it is particularly unstable in sperm and probably meiosis greatly affects their instability, causing an increase in the number of CAG repeats.
Answer:
liquid- enzymes
protein- fat
carbohydrate- saccharides
nuclei acid- dna or deoxyribonucleic acid
Oceanic crust or a less solid piece of oceanic crust will subduct beneath continental crust. Earthquakes occur when the oceanic plate subducts into a trench. Volcanoes are created by the melting of mantle material.
<h3>What does oceanic crust mean?</h3>
The outermost part of the Earth's lithosphere, known as oceanic crust, is created at spreading centres on oceanic ridges that are found at divergent plate boundaries and is found beneath the oceans. The oceanic crust is roughly 4 miles (6 km) thick. Even without the sediment on top, it is made up of many layers.
<h3>What is a characteristic of oceanic crust?</h3>
Compared to continental crust, oceanic crust is both thinner and denser. This is because to the oceans' weight, which has compacted it beneath it. It is also much more recent than continental crust, typically existing within the last 200 million years.
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Answer:
A Recessive
Explanation:
Generally, there are two types of disorders, progressive and recessive. When something is recessive, it is not a dominant gene. The reason why sickle cell anemia is classified as a recessive disorder is because it only affects some people, but it does not affect all those who share DNA. Hope this helps!
