Answer:
Spindle fibers are part of a spindle apparatus that moves chromosomes during mitosis and meiosis to ensure even chromosome distribution between daughter cells. The spindle apparatus of a cell is comprised of spindle fibers, motor proteins, chromosomes, and, in some animal cells, microtubule arrays called asters .
In population genetics, directional selection is a mode of natural selection in which an extreme phenotype is favored over other phenotype, causing the allele frequency to shift over time in the direction of that phenotype
Bacteria, a prokaryote, has circular DNA, as do mitochondria and chloroplasts. This provides support for the Endosymbiotic Theory, which states that the mitochondria and chloroplast in eukaryotic cells were once aerobic bacteria (prokaryote) that were ingested by a large anaerobic bacteria (prokaryote).
Answer:
mRNA: 3' AUG-AAU-GCU-GCC-GGU-GA-5'
amino acids : methionine, asparagine, alanine, arginine, proline
type of mutation: deletion, missense
Explanation:
The mRNA sequence is complementary to the DNA sequence. A always pairs with T, C always pairs with G. Except this is an RNA sequence not a DNA sequence, so T is replaced with U.
The mRNA sequence is translated into an amino acid sequence based on the triplet code. The triplet code for this sequence is shown in the attached picture. Each triplet signifies a specific amino acid. The codon can be identified from the table and placed in sequence. We can see that the new DNA strand has caused a new amino acid sequence. It has also left us with an incomplete sequence, as GA cannot signify an amino acid.
The type of mutation is a single base deletion. We can see that the base C is missing from the 9th amino acid in the original strand. As you can see, this has an ongoing affect on all the bases in the rest of the sequence, as it changes the way the sequence is organised into codons. This results in a missense mutation.
Fossils up to 75,000 years old can be dated with Carbon-14.
Radio isotopes can be used for the age determination of the fossils. Carbon-14 is a common isotope which is used for that purpose. But the half- life of the Carbon-14 is relatively small as 5730 years. That means the amount of Carbon-14 will be half after every 5730 years. Hence, decay is very fast. So Carbon-14 cannot be used forage determination which is more than 75000 years due to the low accuracy.
