30 Questions
What is the main function of nucleic acids according to the text?
To store and transfer information needed for cell function
Which of the following is NOT a type of nucleic acid mentioned in the text?
Peptide nucleic acid (PNA)
What is the Watson-Crick model related to?
The composition and structure of DNA
What is the purpose of describing the primary, secondary and tertiary structure of DNA?
To understand the genetic information stored in DNA
Which type of DNA supercoiling is mentioned in the text?
No specific types of DNA supercoiling are mentioned
What is the purpose of studying molecular biology according to the text?
To understand biological phenomena at the molecular level
What is the orientation of the two DNA strands?
Antiparallel
What type of bonds hold the complementary base pairs together?
Hydrogen bonds
How many hydrogen bonds are present between adenine and thymine?
2
Which of the following statements about the DNA sequence is correct?
The sequence of one strand determines the sequence of the second strand.
What is the role of base stacking in the stability of the DNA double helix?
It balances the repulsive forces of phosphate groups.
What is the function of DNA replication in relation to the complementary base pairing?
DNA replication creates two complementary DNA strands.
How many base pairs or steps are there for each complete turn of the DNA helix?
10.4
What is the width of the B-form of DNA?
2 nm
Which form of DNA has major and minor grooves with widths of 2.2 nm and 1.2 nm respectively?
A form
What is a special characteristic of Z form DNA?
It consists primarily of alternating cytosine and guanine bases (CGCGCG)
Which structural form of DNA is described as thicker and shorter than the B form?
A form
Where is the A form of DNA found?
In moderately dehydrated chromatin
What is the typical length of Z-DNA stretches found at the 5' ends of genes?
12-24 base pairs
What is the primary function of DNA supercoiling?
To enable the packing of large DNA molecules into cells
Which type of supercoiling is more commonly present under normal physiological conditions?
Negative supercoiling
Which type of supercoiling is associated with the winding of DNA around histones?
Left-handed supercoiling
What is the main advantage of having DNA in a negatively supercoiled form?
It makes unwinding of DNA easier
What is the structure of the DNA molecule in a typical prokaryotic organism?
Circular, double-stranded, and supercoiled
What are the four main nucleotides that form the primary structure of DNA?
dAMP, dGMP, dCMP, dTMP
How are the nucleotides linked together in a DNA strand?
By phosphodiester bonds between the 5'-hydroxyl and 3'-hydroxyl groups
What do the alternating sugar-phosphate units form in a DNA strand?
The backbone of each strand
What determines the coding structure (genetic information) of DNA?
The sequence of nitrogenous bases
What is the direction of writing the order of nucleotides in a DNA strand?
5' to 3' direction
What type of helix does the DNA double helix have?
Right-handed helix
Learn about the primary, secondary, and tertiary structure of DNA, as well as the composition and structure based on the Watson–Crick model. Explore DNA denaturation, melting temperature, directionality, and complementarity in DNA structure.
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