1.
A cell builds its proteins from the Instructions encoded in its _________.
Correct Answer
D. Genome
Explanation
A cell builds its proteins from the instructions encoded in its genome. The genome contains all the genetic information necessary for the cell to function and develop. It consists of DNA, which contains the instructions for building proteins through the process of transcription and translation. The genome is located in the nucleus of eukaryotic cells and in the cytoplasm of prokaryotic cells. The genome serves as the blueprint for the cell, providing the necessary information for protein synthesis and overall cellular function.
2.
What process occurs before the other?
Correct Answer
A. Transcription and then Translation
Explanation
Transcription is the process in which RNA is synthesized from a DNA template, while translation is the process in which proteins are synthesized from the RNA template. Transcription occurs before translation because the DNA sequence needs to be transcribed into RNA before it can be translated into a protein. Therefore, transcription is the initial step in gene expression, followed by translation.
3.
Messenger RNA (mRNA) can be best described as:
Correct Answer
C. A short-lived RNA molecule that carries encoded information transcribed from DNA.
Explanation
Messenger RNA (mRNA) is a short-lived RNA molecule that carries encoded information transcribed from DNA. It is synthesized during transcription, where a DNA template is used to produce a complementary mRNA molecule. This mRNA then serves as a template for protein synthesis during translation. It carries the genetic information from the DNA to the ribosomes, where it is decoded into a specific sequence of amino acids to form a protein. mRNA is considered short-lived because it is rapidly degraded within the cell after its role in protein synthesis is complete.
4.
Just like DNA polymerase, RNA polymerase performs a template-directed synthesis in the:
Correct Answer
B. 5'---->3' direction
Explanation
RNA polymerase performs a template-directed synthesis in the 5'---->3' direction. This means that it synthesizes RNA molecules by adding nucleotides to the growing RNA chain in the 5' to 3' direction, using the DNA template strand as a guide. The RNA polymerase moves along the DNA template strand in the 3' to 5' direction, synthesizing the complementary RNA strand in the 5' to 3' direction. This is the same directionality as DNA replication, where DNA polymerase synthesizes the new DNA strand in the 5' to 3' direction.
5.
A Gene is ________________.
Correct Answer
C. A section of DNA that codes for a protein or RNA molecule.
Explanation
A chromosome contains genes and is essentially a gene carrier (it's easier to think about them like that). Genes are basically sections of DNA. However, exons are part of a gene but not what a gene is, and a regulatory sequence is a non-gene portion of DNA.
6.
Transcription is ____________.
Correct Answer
B. The synthesis of RNA from a DNA template.
Explanation
Transcription is the process by which RNA molecules are synthesized from a DNA template. It involves the copying of the genetic information stored in DNA into a complementary RNA molecule. This RNA molecule can then be used as a template for protein synthesis or perform other functions within the cell.
7.
What type of bond forms between complementary base pairs?
Correct Answer
A. Hydrogen
Explanation
Hydrogen bonds form between complementary base pairs. In DNA, adenine pairs with thymine, and guanine pairs with cytosine. These pairs are held together by hydrogen bonds, which occur between the nitrogenous bases. Hydrogen bonds are relatively weak compared to covalent bonds, but they are essential for maintaining the structure and stability of the DNA molecule.
8.
To understand the structure of RNA polymerase, which technique did researchers employ to view this enzyme?
Correct Answer
D. X-ray CrystallograpHy
Explanation
To understand the structure of RNA polymerase, researchers employed X-ray crystallography. This technique involves directing X-rays at a crystalized sample of the enzyme and analyzing the resulting diffraction pattern to determine the molecular structure. X-ray crystallography provides detailed information about the arrangement of atoms within the enzyme, allowing scientists to elucidate its three-dimensional structure and understand its function in transcribing RNA molecules.
9.
How does transcription begin?
Correct Answer
A. Binding of RNA polymerase to the promoter region
Explanation
Transcription, the process of synthesizing RNA from a DNA template, begins with the binding of RNA polymerase to the promoter region of the DNA. The promoter is a specific sequence of DNA that signals the start of transcription. RNA polymerase recognizes and binds to this region, initiating the formation of a transcription bubble and allowing the enzyme to start synthesizing the RNA molecule. The other options refer to different steps in protein synthesis (translation) or post-transcriptional modifications, not the initiation of transcription itself.
10.
Name the process by which the genetic code of DNA is copied into a strand of RNA.
Correct Answer
B. Transcription
Explanation
Transcription is the process by which the genetic code of DNA is copied into a strand of RNA. During transcription, an enzyme called RNA polymerase binds to a specific region of the DNA molecule and synthesizes a complementary RNA strand using the DNA template. This RNA molecule will then be used as a template for protein synthesis during the process of translation.