<span>Commensalism describes the relationship between humans and most of the normal microbiota that live on our human skin. Commensalism describes a relationship between two living organisms. One organism benefits from the other by gaining things such as food and shelter. from the host organism. The host organism does not gain anything, but it is not harmed in any way either.</span>
It would be the first one. Hope this helps :)
The body wall<span> of a star fish is made up of a thin cuticle, an epidermis with a single layer of cells, a thick dermis composed of connective tissue and a thin coelomic myoepithelial layer, which allows the longitudinal and circular musculature.</span>
Answer:
a. Coded for on the X and Y chromosomes
b. Coded for on the X but not Y chromosome
c. Coded for on the Y but not X chromosome
Explanation:
The X and Y chromosomes are the sex chromosomes as they are involved in sex determination. All the genes that are present on the X and Y chromosomes are inherited along with these chromosomes and therefore, exhibit sex-linked inheritance.
X and Y chromosomes share a homologous region. Therefore, the sex-linked genes are defined as the ones present on both X and Y chromosomes as well as the ones that are present on either X or Y chromosomes.
For example, the gene for hemophilia is present on the X chromosome; but not on the Y chromosome. The SRY gene is present only on the Y chromosome.
<span> B. A mutation can result in a change of function. </span>Not all mutations can cause negative effects, but a single mutation is capable of causing profound effect on the physiology and cellular structure of organisms. It can alter the function of proteins causing permanent diseases.
