Continental drift happened around the Jurassic period, 175 million years ago.
<span />
Answer:
The correct answer will be option-D.
Explanation:
In eukaryotes, the process of transcription takes place inside the nucleus whereas translation takes place in the cytosol. So, mRNA has to export to the cytosol from the nucleus.
Before export, the post-transcriptional modification takes place like 5' capping, 3' tailing and splicing mechanism.
The capping is done at 5' end by adding modified guanine (G) nucleotide which protects the mRNA from exonuclease activity and tailing is done at 3' end by adding adenine nucleotides which provides stability to the mRNA.Splicing removes the junk DNA called introns and joins the exons before export.
Thus, option-D is the correct answer.
Answer:
Because of recombination and independent assortment in meiosis, each gamete contains a different set of DNA. This produces a unique combination of genes in the resulting zygote. Recombination or crossing over occur during prophase 1
Answer: A.
Explanation: Scientists think that geographic isolation is a common way for the process of speciation to begin: rivers change course, mountains rise, continents drift, organisms migrate, and what was once a continuous population is divided into two or more smaller populations.