Question

review this diagram; select the response that best describes label #2.
chromatin
sister chromosomes
centromere
chromatid
question 9
this dark mass on skin, a form of skin cancer, is directly due to
meiotic division of normal cells.
the uncontrolled mitosis and growth of abnormal cells
production of excessive protein inhibitors.
the crowding of released antigens

Explanation:

Question 8

A centromere is the region of a chromosome that holds the two sister chromatids together. In the diagram, label #2 is in the middle part of the chromosome structure which is characteristic of the centromere. Chromatin is the complex of DNA and proteins that makes up chromosomes (but not a specific labeled part like this). Sister chromosomes is an incorrect term (should be sister chromatids). A chromatid is one of the two identical halves of a replicated chromosome (label #4 could be a chromatid).

Cancer, including skin cancer, is caused by the uncontrolled mitosis (cell division) and growth of abnormal cells. Meiosis is for sexual reproduction (producing gametes) and not related to cancer. Production of excessive protein inhibitors is not the direct cause. Crowding of released antigens is not the mechanism for cancer development. Uncontrolled cell division (mitosis) of abnormal cells leads to tumor formation.

Answer:

C. centromere

Question 9