C. The vestigial structures. <span>A </span>vestigial structure<span> is an anatomical feature that no longer seems to have a purpose in the current form of an organism of the given species. Often, these vestigial structures were organs that performed some important function in the organism at one point in the past. However, as the population changed due to</span>natural selection<span>, those structures became less and less necessary until they were rendered pretty much useless. While most of these types of structures would probably disappear over many generations, some seem to keep being passed down to offspring even though they have no known function.</span>
Answer:
C) convergent evolution
Explanation:
Convergent evolution is a type of pattern of evolution which occurs when the two unrelated species evolves with the same feature or traits as a result of the exposure of the species to the same environmental conditions.
This type of evolution results in ion the formation of the analogous structure which is functionally similar but is evolved from the same ancestor.
In the given question, since the two unrelated species: plants and animals exhibit the same appearance on different geographical areas thus represents that convergent evolution is taking place.
Thus, C) convergent evolution is the correct answer.
Answer: water, sugar, table salt, baking soda
Explanation:
Answer:
Two different proteins can be produced from a single gene by the following mechanisms:
- Transcriptional Mechanism - Presence of multiple transcription initiation sites in the gene.
- Post-transcriptional Mechanism - Generation of multiple transcripts from a single messenger RNA (mRNA) by the method of alternative splicing.
- Translational Mechanism - Presence of multiple start codons in the mature mRNA transcript, giving rise to multiple proteins.
- Post-translational Mechanism - The protein produced from the mature mRNA transcript can undergo chemical modifications.
Explanation:
- The gene can have multiple transcription initiation sites. When transcription starts from either of the transcription initiation sites it will give rise to different mRNA transcripts, that in turn, will gives rise to different proteins.
- Splicing is the method by which the intron sequences are removed from the precursor mRNA molecules and the exons are linked together to give rise to mature primary mRNA transcripts.
- Alternative splicing is the method involving the differential removal of introns from the precursor mRNA (depending upon the need) resulting in the generation of multiple mature mRNA transcripts that in turn can give rise to multiple proteins.
- Presence of multiple translational start codons in the mature mRNA transcript allows the differential translation of multiple proteins, by the ribosome, from each start codon.
- Proteins produced by translation from the mature mRNA transcript can undergo chemical modifications like glycosylation, methylation or lipidation with each having different functions.
