I think one major difference with that is that animals can move around, go distances in search for food or mate, and thus make the animal densities per geography vary greatly. Birds migrate regularly, so their population densities tend to vary with seasons. Their mobility also depends on the availability of food, so animals go away if there are no food in the area.
Plants on the other hand don't move around faster (they can migrate by reproduction: it's their seeds moving around). Thus their densities tend to be more constant per season/life cycle.
The SEED of a flower develops into the fruit
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.
<u>Answer:</u>
<em>Six centromeres are observed in a prophase cell from an insect, there are </em><u><em>20 pairs of chromosomes present</em></u><em>. </em>
<u>Explanation:</u>
<em>Centromeres is defined as the part of the DNA</em> which are held responsible for the directional changing of chromosomes.
And these chromosome gets divided into <em>2 daughter cells while undergoing the process of mitosis and meiosis. </em>
<em>Chromosome is basically defined as a thin structure</em> as of a threadlike which is made out of nuclei acid and protein which is <em>located at the nucleus of various living cells</em>
All DNA is a cell is harbored in the nucleus, so DNA replication should only occur in the nucleus of the cell.
