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:
A releaser is a stimulus from one animal to another, which causes a particular response.
Explanation:
google
Answer: carbon monoxide is one carbon atom and one oxygen atom
Explanation:
Chloroplasts and mitochondria are similar in the sense that they both contain DNA.
MITOCHONDRIA AND CHLOROPLAST:
- Mitochondria is a membrane bound organelle found in eukaryotic cells. Mitochondria is the energy production site of cells because it is where cellular respiration takes place.
- Chloroplast is another membrane-bound organelle in eukaryotic cells. They are the site of photosynthesis in plants.
- Mitochondria and chloroplast are both involved in energy conversion in cells because electron transport chain occurs in both organelles.
- However, another similarity between these two organelles is that they contain extra-chromosomal DNA.
Learn more about organelles: brainly.com/question/21759042?referrer=searchResults
Answer:
sedimentary rock
Explanation:
fossils are most commonly found in sedimentary rock. Unlike most igneous and metamorphic rocks, sedimentary rocks form at temperatures and pressures that do not destroy fossil remnants. Often these fossils may only be visible under magnification.
