1.
RNA molecule that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the
cell
Correct Answer
C. MRNA
Explanation
mRNA stands for messenger RNA, which carries the genetic information from DNA to the ribosomes in the cytoplasm. It serves as a template for protein synthesis, carrying the instructions for the assembly of amino acids into proteins. Unlike tRNA (transfer RNA) and rRNA (ribosomal RNA), which are involved in the actual process of protein synthesis, mRNA acts as an intermediary, transferring the genetic code from the DNA to the ribosomes. Therefore, mRNA is the correct answer in this context.
2.
Process in which part of the nucleotide sequence of DNA is copied into a complementary sequence in RNA
Correct Answer
B. Transcription
Explanation
Transcription is the correct answer because it refers to the process in which a segment of DNA is used as a template to synthesize a complementary RNA molecule. During transcription, an enzyme called RNA polymerase binds to the DNA at a specific region called the promoter and begins to move along the DNA, synthesizing an RNA molecule that is complementary to the DNA template. This process is crucial for gene expression as it allows the genetic information stored in DNA to be transcribed into RNA, which can then be translated into proteins.
3.
Enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription
Correct Answer
B. RNA polymerase
Explanation
RNA polymerase is the correct answer because it is an enzyme that is similar to DNA polymerase. It binds to DNA and separates the DNA strands during transcription. RNA polymerase is responsible for synthesizing RNA molecules from a DNA template, a process known as transcription. It unwinds the DNA double helix and creates an RNA molecule that is complementary to one of the DNA strands. This RNA molecule will later be used as a template for protein synthesis.
4.
Region of DNA that indicates to an enzyme where to bind to make RNA
Correct Answer
B. Promoter
Explanation
A promoter is a region of DNA that provides instructions to an enzyme (RNA polymerase) on where to bind in order to initiate the process of transcription, where RNA is synthesized from DNA. It acts as a signal for the start of a gene and helps in regulating gene expression. The promoter contains specific sequences that are recognized by the RNA polymerase, allowing it to bind and begin transcribing the DNA into RNA. Therefore, the correct answer is promoter.
5.
Sequences of DNA that is not involved in coding for a protein
Correct Answer
A. Introns
Explanation
Introns are sequences of DNA that are not involved in coding for a protein. They are non-coding regions that are transcribed into RNA but are removed during the process of protein synthesis. Exons, on the other hand, are sequences of DNA that code for protein and are retained in the final mRNA molecule. Codons, on the other hand, are sequences of three nucleotides that code for specific amino acids during translation. Therefore, introns are the correct answer as they are the only option that represents non-coding DNA sequences.
6.
Expressed sequence of DNA; codes for a protein. involved in protein coding
Correct Answer
C. Exons
Explanation
Exons are the expressed sequence of DNA that code for proteins. They are the segments of DNA that are transcribed into mRNA and ultimately translated into proteins. Therefore, exons are directly involved in protein coding.
7.
Three-nucleotide sequence on messenger RNA that codes for a single amino acid
Correct Answer
A. Codon
Explanation
A codon is a three-nucleotide sequence on messenger RNA that codes for a single amino acid. It is responsible for translating the genetic information stored in DNA into a specific sequence of amino acids during protein synthesis. Each codon corresponds to a specific amino acid, allowing the correct amino acids to be assembled in the correct order to form a functional protein.
8.
Process of decoding a mRNA message into a polypeptide chain
Correct Answer
B. Translation
Explanation
Translation is the process of decoding a mRNA message into a polypeptide chain. During translation, the mRNA molecule is read by ribosomes, and the information is used to assemble amino acids in the correct order to form a polypeptide chain. This process occurs in the cytoplasm of the cell and is essential for protein synthesis. Transcription, on the other hand, is the process of synthesizing mRNA from a DNA template. Protein synthesis is a broader term that encompasses both transcription and translation, but in this context, translation specifically refers to the decoding of mRNA into a polypeptide chain.
9.
Group of three bases on a tRNA molecule that are complementary to an mRNA codon
Correct Answer
C. Anticodon
Explanation
The anticodon is a group of three bases on a tRNA molecule that are complementary to an mRNA codon. This means that the anticodon can bind to the corresponding codon on the mRNA during protein synthesis. The binding of the anticodon to the codon ensures that the correct amino acid is added to the growing protein chain. Therefore, the anticodon plays a crucial role in translating the genetic information from the mRNA into the correct sequence of amino acids in a protein.
10.
Type of RNA that makes up the major part of ribosomes
Correct Answer
C. RRNA
Explanation
rRNA, or ribosomal RNA, is the correct answer because it is the type of RNA that makes up the major part of ribosomes. Ribosomes are responsible for protein synthesis, and rRNA plays a crucial role in this process by providing the structural framework for ribosomes and catalyzing the formation of peptide bonds between amino acids. Therefore, rRNA is essential for the functioning of ribosomes and protein production within cells.
11.
Type of RNA molecule that transfers amino acids to ribosomes during protein synthesis
Correct Answer
B. TRNA
Explanation
tRNA, or transfer RNA, is the correct answer because it is the type of RNA molecule that transfers amino acids to ribosomes during protein synthesis. tRNA molecules have a specific anticodon sequence that matches with the codon sequence on mRNA, allowing them to bring the correct amino acid to the ribosome. This process ensures that the amino acids are assembled in the correct order to form a protein. mRNA, on the other hand, carries the genetic information from DNA to the ribosome, while rRNA is a component of the ribosome itself.
12.
Sequence of DNA that codes for a protein and thus determines a trait
Correct Answer
C. Genes
Explanation
Genes are sequences of DNA that contain instructions for building proteins, which in turn determine various traits in an organism. Genes are responsible for passing on genetic information from one generation to the next. They are transcribed into RNA molecules, which are then translated into proteins through the process of protein synthesis. Therefore, genes play a crucial role in determining the characteristics and traits of an organism.
13.
Change in a DNA sequence that affects genetic information
Correct Answer
B. Mutation
Explanation
Mutation is the correct answer because it refers to a change in a DNA sequence that affects genetic information. Mutations can occur in genes, which are segments of DNA that code for specific traits or functions. A mutation can be a point mutation, which involves a change in a single nucleotide base pair, or it can involve larger changes such as deletions, insertions, or rearrangements of DNA. Mutations can have various effects on an organism, ranging from no noticeable impact to causing genetic disorders or providing an advantage in adaptation.
14.
Gene mutation involving changes in one or a few nucleotides
Correct Answer
B. Point mutation
Explanation
A point mutation refers to a gene mutation that involves changes in one or a few nucleotides. This type of mutation can occur when a single nucleotide is substituted, inserted, or deleted in the DNA sequence. Point mutations can have different effects on the resulting protein. For example, a substitution mutation may lead to the replacement of one amino acid with another, potentially altering the protein's structure and function. Overall, point mutations are a common type of genetic variation that can contribute to the diversity of organisms.
15.
Mutation that shifts the “reading” frame of the genetic message by inserting or deleting a nucleotide
Correct Answer
C. Frameshift mutation
Explanation
A frameshift mutation is a type of mutation that occurs when a nucleotide is inserted or deleted in the genetic message, causing a shift in the reading frame. This means that the grouping of nucleotides into codons is disrupted, leading to a completely different amino acid sequence being produced during protein synthesis. Frameshift mutations can have significant effects on the structure and function of the resulting protein, often leading to non-functional or partially functional proteins.
16.
Condition in which an organism has extra sets of chromosomes
Correct Answer
A. Polyploid
Explanation
Polyploid refers to a condition in which an organism has extra sets of chromosomes. This can occur naturally or be induced artificially. Polyploidy can lead to increased genetic variation and can have both positive and negative effects on an organism's traits and reproductive abilities. It is commonly observed in plants, but can also occur in animals.
17.
Group of genes operating together
Correct Answer
B. Operon
Explanation
An operon is a group of genes that are located together on a DNA molecule and are transcribed together as a single mRNA molecule. This allows for coordinated regulation and expression of the genes within the operon. The operon includes a promoter, operator, and the genes themselves. The operator is a regulatory region of the operon that controls the access of RNA polymerase to the genes.
18.
Process in which cells become specialized in structure and function
Correct Answer
B. Differentiation
Explanation
Differentiation refers to the process in which cells undergo specialization in both structure and function. This process allows cells to acquire specific characteristics and perform specific tasks within an organism. Hox genes, which are involved in the regulation of embryonic development, play a crucial role in guiding the differentiation of cells and determining their specific functions. The term "operator" is not directly related to the concept of cell differentiation.