The chromosomal mutation in the zygote can be traced back to "Chromosome 6 in the egg cell".
<u>Option: B</u>
<u>Explanation:</u>
In germ cells i.e. egg or sperm cells, the mutations in chromosome often happen during the meiosis phase. The number of chromosomes in egg cells or sperm cells must be haploid, so that diploid chromosomes form zygote on fertilization. Chromosome mutation in meiosis leads in an additional set of chromosomes or structural defects in the chromosome.
Chromosomal mutations are often caused by chemical agents or by mutagens.
The homologous chromosomes are segregated from sister chromatids throughout cell division, any abnormality at this point allows the chromosomes to be unequally divided or not disjuncted, same is observed in the situation seen in egg cell chromosome 6.
Is this a true or false question?
As per Georg von Békésy's place theory, the position on the basilar film at which waves achieve their pinnacle relies upon the recurrence of a tone. High frequencies deliver waves that crest close to the shut end and are deciphered as shrill sound, while low-recurrence waves travel more remote, topping at the far end, and are translated as low-pitched.
Excitation-contraction coupling refers to the series of events that begins with the excitation of the sarcolemma in response to stimulation by a neurotransmitter, and results in the release of calcium ions from the sarcoplasmic reticulum.
Hence, option D is the 1st process that starts the excitation-contraction coupling.