Describe each stage of the flow of information starting with DNA and ending with a trait? manifest - provide evidence for
The flow of information from DNA to a manifest trait involves several stages, and I will explain each of them in detail:
1. DNA Replication: The process begins with DNA replication, in which the DNA molecule unwinds and separates into two strands. Each of the separated strands serves as a template for the synthesis of a new complementary strand. This results in two identical DNA molecules, each consisting of one original strand and one newly synthesized strand.
2. Transcription: The next stage is transcription, during which a specific segment of DNA acts as a template to make a complementary RNA molecule. Enzymes called RNA polymerases synthesize the RNA molecule by adding complementary RNA nucleotides to the DNA template strand. This process occurs in the nucleus of eukaryotic cells and directly in the cytoplasm of prokaryotes.
3. RNA Processing: After transcription, the newly synthesized RNA molecule undergoes several modifications known as RNA processing. This process involves removing any noncoding regions called introns and joining the remaining coding regions called exons together. Additionally, a cap is added to the beginning of the RNA molecule, while a poly-A tail is attached to its end. These modifications ensure stability and proper functioning of the RNA molecule.
4. mRNA Export: Once RNA processing is complete, the RNA molecule, now called messenger RNA (mRNA), leaves the nucleus and travels to the cytoplasm through nuclear pores. This export allows the mRNA to reach the site where protein synthesis occurs.
5. Translation: In the cytoplasm, the mRNA serves as a template for the synthesis of a protein during translation. Ribosomes, along with transfer RNA (tRNA), read the mRNA sequence and assemble amino acids in the correct order, forming a polypeptide chain. This process continues until a stop codon is reached, signaling the termination of protein synthesis.
6. Protein Folding and Modification: After translation, the newly synthesized polypeptide undergoes various post-translational modifications. These modifications may include folding into its unique three-dimensional structure, addition of chemical groups (such as phosphate or carbohydrate), cleavage of specific regions, and assembly into functional complexes.
7. Protein Function and Trait Manifestation: Finally, the fully folded and modified protein assumes its specific biological function, which directly or indirectly contributes to the manifestation of a particular trait. This trait could be anything ranging from physical characteristics, enzymatic activities, physiological processes, or behavioral patterns.
To summarize, the flow of information from DNA to a manifest trait involves DNA replication, transcription, RNA processing, mRNA export, translation, protein folding and modification, and finally, the functional manifestation of the protein, leading to the trait.