The correct answer is A.
The use of antibacterial drugs can cause modifications in the genetic material of the concerned bacteria. If the genetic material of the bacteria are modify, that means they have undergone mutation. Because the base sequence of the normal and that of the mutated gene is different, antibiotic will not be able to recognize the bacteria again and thus will not be able to attack it.
Answer:
They may change due to environmental changes. for example, if a cactus suddenly experiences a drought, it may change to become better at holding water than before. if it suddenly experiences large amounts of rainfall, it may change to release more water, etc.
There are 206 bones in the human body.
