Answer:
a. Bacteria cannot carry out splicing.
Explanation:
Human genes contain non-coding sequences called introns. Transcription of genes produces primary transcripts that undergo post-transcriptional modifications to produce mature mRNA. These modifications include removal of introns, the addition of 3' poly-A tail and 5' cap. The splicing of introns from primary transcripts is followed by ligation of protein-coding sequences exons to produce mature mRNA. The mRNA leaves the nucleus and serves as a template for protein synthesis.
Splicing of introns requires specific machinery such as several small nuclear ribonucleoprotein complexes, etc. which are not present in a prokaryotic cell. Therefore, a eukaryotic gene like the gene for human growth hormone is not expressed in a bacteria cell as these prokaryotic cells cannot carry out the splicing of introns from pre-mRNA.
A population of squirrels is preyed on by small hawks at maturity. the smaller adult squirrels can escape into burrows. the larger adult squirrels can fight off the hawks. after several generations, the squirrels in the area tend to be very small or very large. this is an example of disruptive selection. In disruptive selection, the extreme traits i.e., very small and very large sizes are favoured over intermediate trait i.e., average size.
