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:
The answer is C) They appear to be the molecular carriers of coded hereditary information.
Explanation:
Why NOT C) They appear to be the molecular carriers of coded hereditary information?
This is the job of the nucleic acids. It is composed of nucleotides which are the basic units of DNA and RNA. They carry genetic information about a certain organism.
<h3 /><h3>True of proteins:</h3>
A) They may be denatured or coagulated by heat or acidity.
<u>Denaturation</u> is the <u>destruction of the protein's secondary and/or tertiary structures</u>. The <u>primary structure is not disrupted due to the tough peptide bonds</u> and can only be broken down by acid. For heat denaturation, hydrogen bonds are destroyed, as in cooking of egg whites and medical equipment sterilization.
B) They have both functional and structural roles in the body.
There are many kinds of proteins that have functional and structural roles like hormones <u>(FSH, LH)</u>, antibodies <u>(IgA, IgM),</u> enzymes <u>(lipase, amylase),</u> for storage/transport <u>(hemoglobin, ferritin)</u>, and locomotion <u>(actin, troponin).</u>
D) Their function depends on their three-dimensional shape.
Just like <u>hemoglobin</u>, it's <u>quaternary structure</u> can carry <u>4 molecules of iron</u> in one go. <u>Enzymes</u> are shaped accordingly to fit a<u> specific substrate</u> <em>(lock-and-key model)</em>
Answer:this area experienced warming temperatures and significantly reduced rainfall, resulting in the formation of the Sahara Desert.
Explanation: hope this helps <3
