A 41-year-old female with a family history of breast cancer has had a baseline mammogram. She states that she performs monthly self-breast exams but really has a hard time evaluating her lumps since she has numerous cysts.
At her annual mammogram, the technician views a suspicious area and refers her to the radiologist. She asks the nurse in the office, How can a lump appear so quickly? The nurse's response is based on which of the following principles?
A)
A tumor is undetectable until it has doubled 30 times and contains at least 1 billion cells.
B)
Many tumor cells never leave the M-phase of the cell cycle.
C)
Cancer cells are undifferentiated and come in various shapes and sizes.
D)
If the breast has a lot of cysts, then the fluid within those sacs makes it difficult to feel the hard lumps of a cancer.
Question 2
A researcher is involved in the investigation of an individual's genetic abnormality. Which of the following situations could the researcher most likely rule out as the genetic cause of a mutation?
A)
Loss of a cytosine-guanine base pair
B)
Formation of an adenine-uracil base pair
C)
Substitution of an adenine-thymine base pair for a cytosine-guanine base pair
D)
Insertion of an extra adenine-thymine base pair
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