Introduction To DNA And RNA Test

The process of copying DNA is called replication. During replication, the DNA molecule unwinds and separates into two strands, each of which serves as a template for the synthesis of a new complementary strand. The result is two identical copies of the original DNA molecule. This process is essential for cell division and the transmission of genetic information from one generation to the next.

James Watson and Francis Crick established the structure of deoxyribonucleic acid in 1953.

The mRNA codons CCU translate into the amino acid proline.

The mRNA codons AUG translates into the instruction code for starting protein synthesis, specifically for the amino acid methionine. This codon serves as the initiation signal for the ribosome to begin translating the mRNA sequence into a polypeptide chain. Methionine is typically the first amino acid incorporated into the growing protein chain during translation.

The term "genome" refers to the complete genetic content of an organism. It includes all of the DNA or genetic material present in the cells of an organism, including both the coding and non-coding regions. The genome contains all the information necessary for the development, functioning, and reproduction of an organism. It is responsible for determining the traits and characteristics of an organism, and it plays a crucial role in the inheritance of genetic information from one generation to the next.

The correct answer is phosphate group, five-carbon sugar, and nitrogen base. This is because nucleotides, the building blocks of DNA, consist of these three components. The phosphate group provides a negative charge and links the nucleotides together, forming the backbone of the DNA molecule. The five-carbon sugar, called deoxyribose, provides the structural framework for the nucleotide. The nitrogen base, which can be adenine (A), thymine (T), cytosine (C), or guanine (G), determines the genetic information carried by the DNA molecule.

Franklin and Wilkins took key photographs of DNA.

The codons UGA, UAA, and UAG are known as stop codons. These codons signal the end of protein synthesis and instruct the ribosome to stop adding amino acids to the growing polypeptide chain. When a stop codon is encountered, a release factor binds to the ribosome, causing the ribosome to detach from the mRNA and release the completed protein. The codons AUC and GUG do not translate to "stop" and instead code for specific amino acids (isoleucine and valine, respectively).

The genetic code refers to the set of rules that determine how the sequence of nitrogenous bases in nucleotides translates into a specific amino acid during protein synthesis. These rules ensure that the correct amino acids are incorporated into the growing polypeptide chain. Therefore, the statement that the genetic code relates the sequence of nitrogenous bases to a particular amino acid is true.

Chargaff is the best match for the phrase "showed that A=T and C=G in the DNA molecule." This is because Chargaff's research in the 1950s demonstrated that the amount of adenine (A) is equal to the amount of thymine (T), and the amount of cytosine (C) is equal to the amount of guanine (G) in DNA. This finding became known as Chargaff's rules and provided crucial evidence for the structure and base pairing of DNA.

The anticodon is not a sequence of three bases in rRNA. Rather, it is a sequence of three bases found on tRNA molecules. The anticodon is complementary to a specific codon on mRNA and is involved in the process of protein synthesis. Therefore, the given statement is false.

A codon refers to a sequence of three bases in mRNA. This sequence acts as a code that determines the specific amino acid that will be incorporated into a growing protein chain during translation. Each codon corresponds to a specific amino acid or a stop signal, allowing the correct assembly of the protein. Therefore, the best match for the term "codon" is "Sequence of three bases in mRNA."

In 1952, Hershey and Chase conducted an experiment using a bacteriophage to determine the genetic material. They labeled the DNA of the bacteriophage with radioactive phosphorus-32 and the protein coat with radioactive sulfur-35. After infecting the bacteria, they found that only the radioactive phosphorus-32 was present in the bacterial cells, indicating that DNA was the genetic material. Therefore, the correct answer is DNA.

In DNA, the base-pairing rules state that adenine (A) always pairs with thymine (T), and cytosine (C) always pairs with guanine (G). This is known as complementary base pairing. The hydrogen bonding between these base pairs allows the DNA strands to hold together and form the characteristic double helix structure. This base-pairing specificity is crucial for DNA replication and transcription processes.

DNA is replicated before cell division. This is because during cell division, the DNA needs to be accurately distributed to the daughter cells. DNA replication ensures that each daughter cell receives an identical copy of the genetic material. This process occurs during the S phase of the cell cycle, which precedes cell division. Therefore, the correct answer is cell division.

The correct answer is Base-Pair Rule. This is because the Base-Pair Rule states that adenine always bonds with thymine and guanine always bonds with cytosine in DNA. These base pairs form the building blocks of the DNA double helix structure.

The mRNA strand is complementary to the DNA strand, with T in DNA being replaced by U in mRNA. Therefore, the correct mRNA strand would be U A G C U A G C U.

The statement is false because regions of DNA that code for proteins are called exons, not extrons or "junk DNA". Exons are the coding regions of DNA that are transcribed into mRNA and then translated into proteins. Junk DNA refers to non-coding regions of DNA that do not have a known function.

During DNA replication, the double-stranded DNA molecule unwinds and separates into two strands. This separation occurs at specific sites called replication forks. Replication forks are the areas where the DNA strands are "unzipped" and serve as templates for the synthesis of new DNA strands. The replication forks are crucial for the replication process as they allow the DNA polymerases to access the separated strands and synthesize new DNA strands in a semi-conservative manner. Helicases, polymerases, and proofreaders are all involved in DNA replication but do not specifically refer to the areas where DNA separates.

Transcription is the process in which DNA is converted into mRNA. This involves the synthesis of an RNA molecule that is complementary to one strand of the DNA. Therefore, the term "DNA to mRNA" best matches transcription as it accurately describes the conversion of genetic information from DNA to mRNA.

The correct answer is "Nonsense." Nonsense refers to DNA sequences that do not code for any functional protein. These sequences may contain mutations or errors that prevent them from being translated into a protein. Nonsense DNA is considered non-functional and does not contribute to the genetic information of an organism.

DNA molecules are made up of two strands of alternating phosphates and deoxyribose sugar. These strands are arranged in a double helix structure, with the phosphates and deoxyribose sugars forming the backbone of each strand. The two strands are held together by hydrogen bonds between complementary nitrogenous bases, adenine (A) with thymine (T) and cytosine (C) with guanine (G). Therefore, the correct answer is two.

At the end of replication, each new DNA molecule is composed of a new strand and an original strand of DNA. During DNA replication, the double-stranded DNA molecule unwinds and each original strand serves as a template for the synthesis of a new complementary strand. This results in two new strands of DNA, each consisting of one original and one newly synthesized strand.

Adenine is the correct answer because it is a nitrogenous base that pairs with thymine in DNA through hydrogen bonding. Adenine and thymine form two hydrogen bonds with each other, stabilizing the DNA double helix structure. Cytosine pairs with guanine, and double helix refers to the overall structure of DNA. Chargaff and X-Ray Diffraction are not directly related to hydrogen bonding with thymine.

mRNA carries the genetic information from DNA to the ribosomes, where it is used as a template for protein synthesis. This process is known as translation, where the sequence of nucleotides in the mRNA is translated into a sequence of amino acids, forming a protein. Therefore, the term "mRNA to protein" best matches the process of translation.

During DNA replication, the double-stranded DNA molecule unwinds and separates into two separate strands. The areas where the separation occurs are called replication forks. At these replication forks, the DNA helicases unwind the DNA strands by breaking the hydrogen bonds between the base pairs. This allows the DNA polymerases to synthesize new complementary strands along each separated template strand. Therefore, replication forks are the correct answer as they are the specific sites where DNA separates during replication.

In DNA replication, the process starts with the separation of the two original strands of DNA. This is followed by the formation of a replication fork, where DNA polymerase adds nucleotides to the DNA strands, creating two new DNA molecules. Therefore, the formation of two new DNA molecules happens last in replication.

False. Each time a new cell is made, the cell does not necessarily receive an exact copy of the parent cell RNA. While the DNA is replicated and passed on to the new cell, RNA molecules can undergo modifications and changes during the process of transcription and translation, leading to variations in the RNA composition of the new cell compared to the parent cell.

DNA polymerases are enzymes that are responsible for synthesizing new DNA strands during replication. They have a proofreading function that allows them to detect and correct errors in the newly synthesized DNA molecules. This proofreading activity helps ensure the accuracy of DNA replication by minimizing the occurrence of mutations. Therefore, DNA polymerases are the correct answer to the question.

The term "Double Helix" best matches "pyrimidine found in DNA" because the double helix structure refers to the twisted ladder shape of DNA, which is formed by two strands of nucleotides. Pyrimidines, including cytosine, are one of the two types of nitrogenous bases found in DNA and are essential components of the double helix structure. Therefore, "Double Helix" is the most appropriate term that describes the pyrimidine found in DNA.