Question

Which of the following is TRUE about cancer? O A person who inherits an oncogenic mutation will be born with cancer. O A person who inherits a tumor suppressor mutation will be born with cancer. O A person who inherits an oncogenic mutation has an increased risk of developing cancer in their lifetime. O Genetic factors are more important than environmental factors for increasing risk of cancer.

Answer 1

A person who inherits an oncogenic mutation has an increased risk of developing cancer in their lifetime is true. Individuals who inherit a mutant allele, have a high risk of developing cancer. Inheriting one mutant allele of tumor-suppressor gene increases to 100 percent the probability that a person will develop cancer.

An inherited mutation is not present in the zygote, but is acquired some time later in life, a single mutation will likely not cause cancer. Environmental factors such as tobacco, diet, infection, drugs, alcohol, chemicals, radiation are more important than genetic or hereditary factors in determining development of most cancers.

Restriction enzymes are naturally produced by bacteria to protect them from viral infections (it depends against bacterial viruses called bacteriophages or phages), are like molecular "scissors" that cut at a specific DNA sequence (restriction enzymes are proteins that recognize a specific short nucleotide sequence and cut the DNA only at that specific site, which is known as restriction site), are enzymes that restrict entry into cells by invading pathogens (in the bacterial cell, restriction enzymes cleave foreign DNA, thereby eliminating infecting pathogens).

The last option is not correct. Restriction enzymes are isolated from bacteria and named after genus, species and strain of that particular bacterium.