The longitudinal halves of a chromosome that has undergone replication are known as chromatids. They will not be called chromosomes until after they are separated during Mitosis. Mitosis distribute the chromatids to daughter cells as a cell divides. The chromosomes are initially replicated in cells undergoing Meiosis, as in preparation for the mitotic division, but then, these chromosomes are divided twice so that four daughter nuclei are produced, each having the haploid chromosome number.
The correct option is A.
When an end of a tuning fork that is vibrating is placed against a table, it produces a sounder that is dramatically louder than the original sound produced by the vibrating tuning fork. At this stage, the tuning fork is forcing the table to vibrate at its own frequency. Thus, the statement in option A is not true.
Darwin's theory of evolution by natural selection can explain how antibiotics are becoming defective because the bacteria that is trying to be fought off might have had a mutation making it more likely to survive. Once that surviving bacteria makes offspring most of the first generation will die from the antibiotic but soon all of their offspring will produce a resistance to that antibiotic.