1.
The transfer of genetic material from one organism to another is
Correct Answer
A. Transformation
Explanation
Transformation is the process by which genetic material is transferred from one organism to another. It involves the uptake and incorporation of foreign DNA into the genome of the recipient organism. This can occur naturally in certain bacteria, or it can be induced in the laboratory through various techniques. Transformation plays a crucial role in genetic engineering, allowing scientists to introduce specific genes into organisms for various purposes such as producing desired traits or studying gene function.
2.
A "jumping gene", a gene with the ability to move from one location to another in a chromosome is
Correct Answer
A. Transposon
Explanation
A "jumping gene" refers to a gene that has the ability to move from one location to another within a chromosome. This type of gene is known as a transposon. Transposons are segments of DNA that can change their position within the genome, allowing them to "jump" to different locations. They can have significant effects on gene expression and genome evolution.
3.
A single stranded nucleic acid containing the bases A, G, C, and U is
Correct Answer
A. Ribonucleic acid
Explanation
A single stranded nucleic acid containing the bases A, G, C, and U is ribonucleic acid. Ribonucleic acid, or RNA, is a type of nucleic acid that is involved in various cellular processes, including protein synthesis. It is composed of a single strand of nucleotides, with the bases adenine (A), guanine (G), cytosine (C), and uracil (U). RNA plays a crucial role in gene expression and the transfer of genetic information from DNA to protein.
4.
The first stage of gene expression in which an RNA copy of DNA is made is
Correct Answer
A. Transcription
Explanation
Transcription is the correct answer because it refers to the process in gene expression where an RNA molecule is synthesized from a DNA template. During transcription, RNA polymerase binds to the DNA and creates a complementary RNA strand by adding nucleotides. This RNA molecule, known as messenger RNA (mRNA), carries the genetic information from the DNA to the ribosomes where it is used as a template for protein synthesis. The other option, "wheelbarrow", is unrelated and does not describe any stage of gene expression.
5.
An environmental agent that can alter the structure of DNA is
Correct Answer
A. Mutagen
Explanation
A mutagen is an environmental agent that has the ability to change the structure of DNA. This can result in genetic mutations, which are changes in the DNA sequence. Mutagens can include chemicals, radiation, and certain viruses. These agents can cause alterations in the DNA molecule, such as base pair substitutions, deletions, or insertions. These changes can have various effects, ranging from no impact to detrimental consequences, such as the development of cancer or other genetic disorders. Therefore, a mutagen is the correct answer as it specifically refers to an agent that can modify DNA structure.
6.
Three nucleotide sequence in mRNA specifying a particular amino acid is
Correct Answer
A. Codon
Explanation
A codon is a three-nucleotide sequence found in mRNA that codes for a specific amino acid during protein synthesis. It acts as a template for the assembly of amino acids in the correct order to form a protein. Each codon corresponds to a specific amino acid or a stop signal, and the sequence of codons determines the sequence of amino acids in a protein. Therefore, the correct answer is "codon" because it accurately describes the three-nucleotide sequence in mRNA that specifies a particular amino acid.
7.
Three nucleotide sequence of a tRNA molecule is
Correct Answer
A. Anticodon
8.
Spiral of two strands as in DNA structure is
Correct Answer
A. Double helix
Explanation
The correct answer is "double helix" because the spiral structure of DNA consists of two intertwined strands that resemble a twisted ladder. The two strands are held together by hydrogen bonds between their nucleotide bases, forming a stable and unique structure known as a double helix. This arrangement allows for DNA replication and protein synthesis, making it crucial for the storage and transmission of genetic information.
9.
The correspondence between nucleotide triplets in DNA and the amino acids in proteins is
Correct Answer
A. Genetic code
Explanation
The correct answer is genetic code. The genetic code refers to the specific correspondence between nucleotide triplets (codons) in DNA and the amino acids they encode in proteins. This code is universal across all living organisms and is essential for the synthesis of proteins during gene expression. It determines the sequence of amino acids in a protein, which in turn determines its structure and function. Understanding the genetic code is crucial in deciphering the genetic information stored in DNA and studying the processes of transcription and translation.
10.
The molecule that binds to the repressor protein, thereby allowing DNA to be transcribed is
Correct Answer
A. Inducer
Explanation
The molecule that binds to the repressor protein, thereby allowing DNA to be transcribed is an inducer. Inducers are small molecules that can bind to repressor proteins and cause a conformational change, preventing them from binding to the DNA. This allows the RNA polymerase to access the DNA and initiate transcription. In the absence of the inducer, the repressor protein binds to the operator region of the DNA, blocking the transcription process. However, when the inducer is present, it binds to the repressor protein, causing it to dissociate from the DNA and allowing transcription to occur.
11.
Noncoding portions of the DNA are
Correct Answer
A. Intron
Explanation
Introns are noncoding portions of DNA that are found within genes. They are transcribed into RNA but are removed during the process of RNA splicing, before the final mRNA molecule is formed. Introns do not code for proteins and their function is not fully understood, but they are believed to have regulatory roles in gene expression. Wheelbarrow, on the other hand, is not related to DNA or genetics and is not a noncoding portion of DNA.
12.
The second stage of gene expression in which three kinds of RNA work together to assemble amino acids into a protein molecule is
Correct Answer
A. Translation
Explanation
Translation is the correct answer because it refers to the second stage of gene expression where three types of RNA (messenger RNA, transfer RNA, and ribosomal RNA) work together to convert the genetic information encoded in DNA into a protein molecule. During translation, the ribosome reads the mRNA sequence and uses tRNA molecules to bring the corresponding amino acids, which are then joined together to form a protein. This process is essential for protein synthesis in cells.
13.
A subunit of DNA or RNA consisting of three parts: a sugar, a phosphate, and a base, is
Correct Answer
A. Nucleotide
Explanation
A subunit of DNA or RNA consisting of three parts: a sugar, a phosphate, and a base is called a nucleotide. Nucleotides are the building blocks of DNA and RNA molecules, and they play a crucial role in carrying and transmitting genetic information. The sugar in a nucleotide can be either deoxyribose (in DNA) or ribose (in RNA), and the base can be adenine, thymine (only in DNA), cytosine, guanine, or uracil (only in RNA). The phosphate group connects the sugar and the base together, forming the backbone of the DNA or RNA strand.
14.
Protein that blocks transcription by preventing RNA polymerasefrom moving along the gene is
Correct Answer
A. Repressor protein
Explanation
A repressor protein is a protein that inhibits the process of transcription by binding to specific DNA sequences, thereby preventing the RNA polymerase from moving along the gene and transcribing it into RNA. This blocking action helps regulate gene expression by preventing the production of certain proteins when they are not needed.
15.
This os one of the two smaller nucleotide bases, ex. cytosine or thymine.
Correct Answer
A. Pyrimidine
Explanation
Pyrimidine is the correct answer because it is one of the two smaller nucleotide bases, along with purine. Pyrimidines include cytosine and thymine, while purines include adenine and guanine. Therefore, pyrimidine fits the given description and is the appropriate answer.
16.
This is one of the two larger nucleotide bases, ex. adenine or guanine.
Correct Answer
A. Purine
Explanation
Purine is one of the two larger nucleotide bases, along with pyrimidine. It includes adenine and guanine, which are essential components of DNA and RNA molecules. Purines are characterized by a double-ring structure, which distinguishes them from pyrimidines that have a single-ring structure. The presence of purines in nucleic acids is crucial for the proper functioning of genetic information transfer and protein synthesis. Thus, purine is the correct answer in this context.
17.
The use of genetic information in DNA to make proteins is
Correct Answer
A. Gene expression
Explanation
Gene expression refers to the process by which the information stored in a gene is used to create a functional protein. DNA contains the genetic information in the form of genes, and gene expression involves the transcription of the DNA into RNA and the translation of the RNA into proteins. This process is essential for the functioning of cells and organisms, as proteins perform various important functions in the body. Therefore, the use of genetic information in DNA to make proteins is accurately described as gene expression.
18.
The portions of DNA that code for protein are
Correct Answer
A. Exon
Explanation
Exons are the portions of DNA that code for proteins. They are the segments of DNA that are transcribed into mRNA and eventually translated into proteins. Exons contain the necessary information for the synthesis of functional proteins, while the non-coding regions called introns are removed during RNA processing. Therefore, exons play a crucial role in determining the structure and function of proteins in an organism.
19.
Write the complementary DNA strand for this DNA strand:
A T C G A A C G C T T A
IMPORTANT: Be sure to put a space between each pair of letters.)
(HINT: It may be helpful to write this strand on a piece of paper and then write the complementary strand underneath it.)
Correct Answer
A. T A G C T T G C G A A T
Explanation
The complementary DNA strand is formed by pairing each nucleotide with its complementary base. In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). Therefore, the complementary DNA strand for the given DNA strand is T A G C T T G C G A A T.
20.
Write the mRNA sequence that would be coded for by the DNA sequence from the previous question A T C G A A C G C T T A
IMPORTANT: Be sure to put a space between each pair of letters.)
(HINT: It may be helpful to write this strand on a piece of paper and then write the complementary strand underneath it.)
Correct Answer
A. U A G C U U G C G A A U
21.
The purpose of translation is to put amino acids in a chain to make a
Correct Answer
A. Protein
Explanation
Translation is the process by which amino acids are assembled in a specific sequence to form a protein. Proteins are essential molecules that perform a wide range of functions in living organisms, including structural support, enzymatic activity, and cell signaling. Therefore, the purpose of translation is to produce proteins, not a wheelbarrow or any other unrelated molecule.