Answer: Earth's rotation is slowing slightly with time,thus, a day was shorter in the past. This is due to the tidal effects the Moon has on Earth's rotation. Atomic clocks show that a modern-day is longer by about 1.7 milliseconds than a century ago.
Answer:
Deletion mutation usually takes place due to the errors in the process of DNA replication . DNA polymerase slips off on the template strand due to which that part of the DNA is not coded in the daughter strand.
It can skip from one nucleotide (point mutation) to an entire gene. Point deletion can result in frame-shift mutation if it takes place in the beginning or middle of the gene. However, if it takes place at the end of the gene then it may cause no harm.
For example, let us assume the original sequence of DNA as ATG-AGT-CGT-ATA-TAA. It will result in the formation of methionine, serine, arginine, isoleucine, and STOP codon.
Point deletion at the end of the gene results in ATG-AGC-GTA-TAT-AA sequence. Now it will code for methionine, serine, valine, and tyrosine as AA will not code for anything. Hence, the sequence of the protein remains the same.
Hence, if deletion mutation takes place at the last or stop codon of the gene then it will cause no harm or change in the protein sequence. However, if it takes place before that then it may result in frame-shift mutation and thus a mutated protein.
