Vestigial structures are considered evidence since scientists believe they are structures that were once used by a species ancestors but are no longer needed. They do not impair the organisms in any way, so there is no need for evolution to get rid of them. Vestigial structures are anatomical features that no longer seems to have a function or purpose in the current form of an organism of the given species. Examples are wisdom teeth, the muscles of the ear, the appendix, the tail bone among others in human.
A) 100% red pigment
b) 75% black pigment
c) 25% of offspring is expected to lack both red and black pigments in their skin
Answer:
Paul has natural active immunity, while Nicholas has artificial active immunity.
Explanation:
Natural active immunity is an immunity that occurs when an individual is exposed to a disease causing organism, gets infected, and also become immune to the disease due to the primary immune response. From the question, Paul has natural active immunity because he had chicken pox before, and the virus that causes chicken pox has interacted with his immune response, hence, making him to develop natural immunity to the disease.
Artificial active immunity is an immunity that an individual acquires when small amount of immunity to a disease is deliberately exposed to his body. Artificial active immunity is usually produced in the form of vaccinations. From the question, Nicholas has artificial active immunity because chicken pox vaccines were intentionally introduced to his body.
The cell cycle or cell-division cycle is the series of events that take place in a cell leading to its division and duplication of its DNA (DNA replication) to produce two daughter cells. In bacteria, which lack a cell nucleus, the cell cycle is divided into the B, C, and D periods. The B period extends from the end of cell division to the beginning of DNA replication.
