AP Bio Ch 15 Quiz Trivia

The given DNA nucleotide sequence is A-A-A-C-A-A-C-T-T. To find the complementary sequence of mRNA, we need to replace each nucleotide with its complementary base. A pairs with U, T pairs with A, C pairs with G, and G pairs with C. Therefore, the complementary sequence of mRNA is U-U-U-G-U-U-G-A-A.

Transfer RNA (tRNA) carries the amino acids that are added to the growing polypeptide chain during protein synthesis. tRNA molecules have specific anticodons that are complementary to the codons on the messenger RNA (mRNA), allowing them to bind to the mRNA and deliver the corresponding amino acid. This process ensures that the correct amino acids are added in the correct order, forming a specific sequence of amino acids that make up the polypeptide chain. Therefore, tRNA is responsible for the accurate translation of the genetic code into proteins.

Ribosomal RNA (rRNA) is the correct answer because it is the class of RNA molecules that is linked with proteins in forming the large and small subunits of a cytoplasmic structure called the ribosome. The ribosome is responsible for protein synthesis in cells, and rRNA plays a crucial role in this process by providing the structural framework for the ribosome and assisting in the binding of transfer RNA (tRNA) molecules during translation. Messenger RNA (mRNA) carries the genetic information from DNA to the ribosome, while primary mRNA transcript refers to the initial RNA molecule transcribed from DNA before it undergoes processing.

Translation is not the first step in the production of a protein from the information in DNA. The first step is transcription, where the DNA sequence is copied into an RNA molecule. After transcription, the RNA molecule is then translated into a protein in a process called translation. Therefore, the given statement is false.

The given statement is false because transcription actually begins at a region of the DNA called the promoter, not the polymerase. The promoter is a specific sequence of DNA that signals the start of transcription and binds to RNA polymerase, allowing it to initiate the process of transcribing DNA into RNA. Therefore, the correct answer is false.

Linus Pauling's guess was not close to the actual DNA structure proposed by Watson and Crick. He incorrectly guessed that there were three support strands running down the middle, whereas the actual structure has two support strands running along the outside. Additionally, Pauling's guess had the bases sticking out the sides, whereas they are actually paired in the middle. Therefore, all of the above statements vary from the real model.

The correct answer is that DNA serves as a template for the production of mRNA. During protein synthesis, the DNA molecule is transcribed into mRNA, which carries the genetic information from the DNA to the ribosomes. The mRNA molecule is then translated into a protein by the ribosomes, using the information encoded in the DNA template. This process allows the DNA to serve as a blueprint for the production of proteins.

Split genes are a type of gene structure where the coding sequences, known as exons, are interrupted by non-coding sequences called introns. This means that split genes have both exons and introns present in their DNA sequence. Therefore, the statement "Split genes are those that contain both exons and introns" is true.

Gene expression refers to the process by which the information in a gene is used to create a functional product, such as a protein. However, it is not true that gene expression only occurs when a protein is produced. Gene expression can also result in the production of other molecules, such as RNA molecules, which may have regulatory or structural roles in the cell. Additionally, gene expression can occur without the production of any final product, as in the case of non-coding RNA molecules or regulatory sequences that control the expression of other genes. Therefore, the statement is false.

The primary mRNA transcript is the initial RNA molecule synthesized from DNA during transcription. It undergoes several modifications, including splicing and addition of a 5' cap and a poly-A tail, to form mature mRNA. This process is more complex and regulated in eukaryotes compared to prokaryotes. Therefore, the primary mRNA transcript is found in almost no prokaryotes.