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.
Answer
La corteza terrestre temprana apareció hace aproximadamente 4.500 millones de años, después de las últimas etapas de acreción planetaria.
Answer:
Genetic code is the term we use for the way that the four bases of DNA--the A, C, G, and Ts--are strung together in a way that the cellular machinery, the ribosome, can read them and turn them into a protein. In the genetic code, each three nucleotides in a row count as a triplet and code for a single amino acid.
Explanation:
