Jim has become particularly interested in the genetic basis of cancer and has spent considerable time reading published papers about oncogenes. He learned that as early as 1972 researchers suggested that mutations in proto-oncogenes caused by carcinogens can convert them to oncogenes. He asked you to answer a couple of questions about this because he did not have the biology background to totally understand. Jim learned that some cancer cells produce more growth-stimulating proteins than others. What would you give him as a plausible explanation

Proto-oncogenes may have mutated to become oncogenes in these cells

Explanation:

Cancer cells are characterized by key properties such as an abnormally rapid rate and poor differentiation. Proto-oncogenes are genes that lead normal cells to become cancer cells when they are mutated. Many proto-oncogenes are involved in the control and progression of the cell cycle, and apoptosis (programmed cell death) pathway. Some examples of protooncogenes include 1-the Ras gene, which is required for differentiation, growth, and cell survival (mutations of this gene have been reported in pancreatic cancer, lung cancer, colon cancer and thyroid cancer), 2-the Myc gene (mutated in Burkitt's lymphoma), 3- the Her2 receptor (a receptor kinase associated with breast cancer), etc.

cats ; snakes

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: