Answer:
A mutation in Ras protein which will cause hyperactivity will eventually lead to cancer.
Explanation:
Ras protein was first discovered in Rous sarcoma virus (RSV) and it is a proto-oncogene product. In normal conditions, it plays an important role in cellular signalling but in case of gain of function/hyperactivity it gets converted into cellular oncogene. In several types of cancers a point mutation has been reported in Ras protein.
Just like G protein, it is also a GTPase switch protein but unlike G protein which is trimeric, it is monomeric. In the plasma membrane, it is attached with the help of lipids like prenyl or palmitoyl groups. During signal transduction pathway when it gets activated, it downstream activates MAPK pathway and causes gene expression but when it gets hyperactivated it causes over expression of genes leading to cancer.
Answer: Option D
Explanation:
The bacteria can undergo cell differentiation in response to the environmental conditions.
The oxidative stress, antibiotic exposure, stress conditions are some of the external conditions due to which the bacterial cell can respond in the cell differentiation.
The bacterial species can divide based in the conditions in which they are put. So it is true that under stress conditions the bacterial cell can undergo cell differentiation.
Answer:
Cell theory refers to the idea that cells are the basic unit of structure in every living thing. Development of this theory during the mid 17th century was made possible by advances in microscopy. This theory is one of the foundations of biology.
Science has shown that smoking causes cancer. which is an example of how society responded to this information