1.
Who discovered the structure of DNA?
Correct Answer
A. Watson, Crick and Franklin
Explanation
Watson, Crick, and Franklin are credited with discovering the structure of DNA. James Watson and Francis Crick, two scientists at the University of Cambridge, proposed the double helix structure of DNA in 1953. They built upon the work of Rosalind Franklin, a British biophysicist, who had produced X-ray crystallography images of DNA. Franklin's images provided crucial evidence for the helical structure of DNA. While Maurice Wilkins also played a significant role in the discovery, he is not mentioned as an option in this question. Mendel, Einstein, and Samuelson are not associated with the discovery of DNA's structure.
2.
In DNA, what pairs with Adenine?
Correct Answer
D. Thymine
Explanation
Adenine pairs with Thymine in DNA. This is because in DNA, the base pairing rule states that Adenine always pairs with Thymine, and Guanine always pairs with Cytosine. This complementary base pairing is essential for DNA replication and the transmission of genetic information.
3.
What holds one strand of DNA to the other strand?
Correct Answer
C. Hydrogen bonds
Explanation
Hydrogen bonds hold one strand of DNA to the other strand. This is because the nitrogenous bases in DNA (adenine, thymine, cytosine, and guanine) form hydrogen bonds with each other. Adenine pairs with thymine through two hydrogen bonds, while cytosine pairs with guanine through three hydrogen bonds. These hydrogen bonds provide the stability and complementary base pairing necessary for DNA replication and transcription. Covalent bonds involve the sharing of electrons, ionic bonds involve the transfer of electrons, and carbon bonds are not specific types of bonds.
4.
What base is in RNA, but not in DNA?
Correct Answer
E. Uracil
Explanation
RNA (ribonucleic acid) is a molecule that is similar to DNA (deoxyribonucleic acid) but contains the base uracil instead of thymine. In DNA, thymine pairs with adenine, while in RNA, uracil pairs with adenine. Therefore, uracil is the base that is present in RNA but not in DNA.
5.
How many strands are RNA and DNA?
Correct Answer
B. RNA is single stranded and DNA is double stranded
Explanation
RNA is single stranded and DNA is double stranded. This is because RNA is made up of a single strand of nucleotides, while DNA is made up of two strands that are complementary to each other and form a double helix structure. The single-stranded nature of RNA allows it to fold into complex secondary structures and perform various functions in the cell, such as carrying genetic information and catalyzing chemical reactions. On the other hand, the double-stranded structure of DNA provides stability and allows for accurate replication and transmission of genetic information during cell division.
6.
Which of these nucleic acids contain nitrogenous bases?
Correct Answer
C. DNA and RNA
Explanation
Both DNA and RNA contain nitrogenous bases. These nitrogenous bases are adenine (A), cytosine (C), guanine (G), and thymine (T) in DNA, and adenine (A), cytosine (C), guanine (G), and uracil (U) in RNA. These nitrogenous bases are essential for the genetic information storage and transfer processes in both DNA and RNA.
7.
DNA is the instructions for the cell. If it is in the nucleus, how do the instructions get into the cytoplasm and to the organelles?
Correct Answer
B. Messenger RNA (mRNA) is a copy of the instructions contained in DNA and it can move from the nucleus to the cytoplasm.
Explanation
mRNA serves as a messenger that carries the instructions from DNA in the nucleus to the cytoplasm. It is a copy of the DNA instructions and is capable of moving through the nuclear membrane pores into the cytoplasm. Once in the cytoplasm, mRNA can deliver the instructions to the organelles, allowing them to carry out their functions. Therefore, the correct answer is that mRNA is responsible for transferring the instructions from the nucleus to the cytoplasm and organelles.
8.
Where is DNA found?
Correct Answer
A. In the nucleus
Explanation
DNA is found in the nucleus of a cell. The nucleus is the control center of the cell and contains the genetic material, including DNA. DNA carries the instructions for the development, functioning, and reproduction of all living organisms. It is responsible for storing and transmitting genetic information from one generation to the next. The DNA in the nucleus is organized into structures called chromosomes.
9.
What is the smallest unit of nucleic acids?
Correct Answer
C. Nucleotide
Explanation
A nucleotide is the smallest unit of nucleic acids. Nucleic acids, such as DNA and RNA, are made up of long chains of nucleotides. Each nucleotide consists of a sugar molecule, a phosphate group, and a nitrogenous base. These nucleotides are linked together through phosphodiester bonds to form the backbone of the nucleic acid molecule. Therefore, nucleotides are the building blocks of nucleic acids and play a crucial role in storing and transmitting genetic information.
10.
Which nucleic acid contains ribose?
Correct Answer
B. RNA
Explanation
RNA contains ribose because ribose is a sugar molecule that is a component of RNA. DNA, on the other hand, contains deoxyribose, which is a slightly different sugar molecule. Therefore, the correct answer is RNA.
11.
What are the 3 parts of a nucleotide?
Correct Answer
D. Sugar (either ribose or deoxyribose), Nitrogenous base, pHospHate group
Explanation
The correct answer is sugar (either ribose or deoxyribose), nitrogenous base, and phosphate group. A nucleotide is composed of these three components. The sugar can be either ribose or deoxyribose, and it forms the backbone of the nucleotide. The nitrogenous base can be adenine, guanine, cytosine, or thymine, and it pairs with another nitrogenous base in DNA. The phosphate group is responsible for linking the nucleotides together to form the DNA or RNA strand.
12.
DNA stands for
Correct Answer
A. Deoxyribonucleic acid
Explanation
DNA stands for deoxyribonucleic acid. It is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms. The term "deoxyribose" refers to the sugar component of the DNA molecule, which is deoxyribose. "Nucleic acid" indicates that DNA is composed of nucleotides, which are the building blocks of the molecule. Therefore, the correct answer is deoxyribonucleic acid.
13.
The process by which DNA makes a copy of itself is called what?
Correct Answer
A. Replication
Explanation
The process by which DNA makes a copy of itself is called replication. During replication, the DNA molecule unwinds and separates into two strands, and each strand serves as a template for the synthesis of a new complementary strand. This results in two identical DNA molecules, each containing one original strand and one newly synthesized strand. Synthesis, translation, and transcription are all important processes in gene expression and protein synthesis, but they are not specifically related to DNA copying itself.
14.
Which of the following shows the sequence and orientation of the primer’s DNA template?
Correct Answer
C. 3’-GAATCCAGTAGTCTGATC-5’
Explanation
The correct answer, 3'-GAATCCAGTAGTCTGATC-5', shows the sequence and orientation of the primer's DNA template. The primer's DNA template is read from the 3' end to the 5' end, and the sequence is GAATCCAGTAGTCTGATC.
15.
By which process RNA is made from DNA?
Correct Answer
A. Transcription
Explanation
Transcription is the process by which RNA is made from DNA. During transcription, an enzyme called RNA polymerase binds to the DNA strand and synthesizes a complementary RNA molecule. This RNA molecule carries the genetic information from the DNA and can be used to produce proteins during translation. Therefore, transcription is the correct process by which RNA is made from DNA.