KBAT Question

1. A farmer wants to breed a good variety of banana plants for commercial production.
   (a) Suggest a suitable method to be used.
   (b) Explain how the method named in (a) can increase the crop yield.
Answer : (a) The suitable method is cloning or tissue culture.
                (b) This method produces large numbers of clones within a short period of time. Clones inherit good and desirable characteristics, such as higher resistance to diseases, fast growth rate and larger fruits.

2. Every year, new students who are going to enter IPTA need do medical  check-ups followed by X-ray examination. The Ministry of Health stated that the pregnant women should not take X-ray examination while the normal people should not be allowed to do another X-ray examination in less than 6 months. Explain why.
Answer : The exposure to X-ray will damage the DNA of the cell. The cell proliferates widly by repeated, uncontrolled mitosis to produce cancer cells due to (severe) disruption to the mechanism that control mechanism that controls the cell cycle. Cancer cells divide uncontrollably heeding the
cell cycle control mechanism. These cells compete with surrounding normal cells for nutrients and energy (for growth). They invade and destroy the neighbouring cells. They may spread to other organs and initiate cancers there.

3. Explain how gamma radiation can be used to treat cancer patients.
Answer : Radiotherapy using gamma ray is a method used in treating cancer. Radiotherapy uses radioactive rays. Cancer cells are killed when exposed to the radioactive rays. Therefore cancer cells stop dividing and increasing in number.