If a gene is found only on the X chromosome and not the Y chromosome, it is
said to be a sex-linked trait. Because the
gene controlling the trait is located on the sex chromosome, sex linkage is
linked to the gender of the individual. Usually such genes are found on the
X chromosome. The Y chromosome is thus missing such genes (See Diagram above.).
The result is that females will have two copies of the sex-linked gene while
males will only have one copy of this gene. If the gene is recessive, then males
only need one such recessive gene to have a sex-linked trait rather than the
customary two recessive genes for traits that are not sex-linked. This is why
males exhibit some traits more frequently than females.
<span>Examples of Sex-linked Traits: </span>
Red-green colorblindness
Male Pattern Baldness
Hemophilia
<span>Duchenne Muscular Dystrophy</span>
Answer:
Yes...This is an example of speciation by natural selection
Explanation:
As we know that natural selection always promote those evolutionary changes that are necessary. Changes that happen in chromosome number always promote with a specie that is closely related to the parent specie and produce fertile off-springs. These new generations are most adaptable and can survive in the environment more efficiently than the previous ones.
Additionally, other than natural selection, speciation can also happen as a result of random mutations, genetic drift and by means of artificial selection as well. But the natural likelihood of all these is probably low as compared to that of natural selection.
Since all of the three beetle species posses the protein, we can use it to determine their relations. We can study the sequence of the amino acids that make the protein and the 3D structure of the protein. The more differences there are in amino acid sequences and the structure of the protein, the species are more distantly related because they have diverged a long time ago and their genes that produce that protein have undergone many changes over time.
Answer: Coastal areas have moderate temperature because the land absorbs and radiates heat much faster than sea. So, during the day cool air from sea rush towards the land and during night cool air from the land rush towards sea