What is the function of an endoplasmic reticulum?

It is mainly responsible for the transportation of proteins and other carbohydrates to another organelle, which includes lysosomes, Golgi apparatus, plasma membrane, etc.
They play a vital role in the formation of the skeletal framework.
They provide the increased surface area for cellular reactions.
They help in the formation of nuclear membrane during cell division.
They play a vital role in the synthesis of proteins, lipids, glycogen and other steroids like cholesterol, progesterone, testosterone, etc.http://biology.tutorvista.com/animal-and-plant-cells/endoplasmic-reticulum.html

Essential for a scientist to do for credibility

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.