Which of the following is true about DNA? A) DNA is a single-stranded molecule. B) DNA contains uracil. C) DNA has a sugar-phosphate backbone. D) DNA strands are parallel.
C) DNA has a sugar-phosphate backbone.
Which of the following forms the backbone of a DNA molecule?
The backbone of a DNA molecule is formed by sugar (deoxyribose) and phosphate groups.
In a double helix, what is the orientation of the two DNA strands?
In a double helix, the two DNA strands are antiparallel, meaning they run in opposite directions.
Which of the following is used to construct a molecule of DNA? A) Amino acids. B) Lipids. C) Nucleotides. D) Carbohydrates.
C) Nucleotides.
This is a DNA model. What conclusion can you draw from this model?
The DNA model shows a double helix structure with antiparallel strands and complementary base pairing.
Which best describes the structure of DNA? A) A single-stranded molecule. B) A double helix with antiparallel strands. C) A molecule composed of lipids. D) A molecule with a triple helix structure.
B) A double helix with antiparallel strands.
What are the main structural features of DNA found in the Z conformation?
In the Z conformation, DNA has a left-handed helix with a zigzag sugar-phosphate backbone.
Which of the following is not a characteristic of DNA? A) Double helix structure. B) Contains uracil. C) Sugar-phosphate backbone. D) Antiparallel strands.
B) Contains uracil.
What are the three key roles of DNA?
The three key roles of DNA are storing genetic information, replicating for cell division, and encoding instructions for protein synthesis.
Why is DNA an incredibly important molecule?
DNA is important because it stores genetic information, guides development and functioning, and allows for inheritance and evolution.
Which of the following statements best describes the orientation of the two strands of DNA? A) The strands are parallel. B) The strands are antiparallel. C) The strands are identical. D) The strands are composed of proteins.
B) The strands are antiparallel.
Which statement about the polarity of DNA strands is true?
DNA strands have polarity, with one end being 5' (phosphate group) and the other end being 3' (hydroxyl group).
Which of the following statements is true of DNA but not RNA? A) Contains uracil. B) Has a sugar-phosphate backbone. C) Is double-stranded. D) Contains ribose sugar.
C) Is double-stranded.
In the structure of DNA, what is the role of the sugar-phosphate backbone?
The sugar-phosphate backbone provides structural support and stability to the DNA molecule.
Which of the following is a characteristic of DNA? A) Contains uracil. B) Is single-stranded. C) Has a sugar-phosphate backbone. D) Contains ribose sugar.
C) Has a sugar-phosphate backbone.
What bases are found in DNA?
The bases found in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G).
Which one of the following nucleotide pair bonds would be found in a DNA molecule? A) Adenine-Uracil. B) Cytosine-Guanine. C) Thymine-Uracil. D) Guanine-Uracil.
B) Cytosine-Guanine.
In a DNA molecule, what is the significance of complementary base pairing?
Complementary base pairing ensures accurate replication and transcription by pairing adenine with thymine and cytosine with guanine.
Which two main structural features result in complementary sequences of DNA forming a double helix?
The antiparallel orientation and complementary base pairing result in DNA forming a double helix.
What is the relationship between DNA and RNA?
DNA serves as the template for RNA synthesis during transcription, and RNA carries the genetic code for protein synthesis.
How did Rosalind Franklin contribute to the understanding of DNA structure?
Rosalind Franklin's x-ray diffraction image, Photo 51, provided crucial evidence for the double helix structure of DNA.
Which of the following statements regarding a DNA double helix is always true? A) The strands are parallel. B) The strands are antiparallel. C) The strands are identical. D) The strands are composed of proteins.
B) The strands are antiparallel.
Which statement regarding a DNA double helix is true? A) The strands are parallel. B) The strands are antiparallel. C) The strands are identical. D) The strands are composed of proteins.
B) The strands are antiparallel.
What are the bases of DNA?
The bases of DNA are adenine (A), thymine (T), cytosine (C), and guanine (G).
What is the structure of the DNA molecule?
The structure of the DNA molecule is a double helix with two antiparallel strands of nucleotides.
What is the name of the sugar molecule in the DNA helix?
The sugar molecule in the DNA helix is deoxyribose.
Who was the scientist responsible for capturing Photo 51, and what technique did she use to obtain it?
Rosalind Franklin captured Photo 51 using x-ray diffraction.
Which two scientists used Photo 51 to help describe the structure of DNA in 1953?
James Watson and Francis Crick used Photo 51 to help describe the structure of DNA.
What are the components of a single DNA nucleotide?
A DNA nucleotide consists of a phosphate group, a five-carbon sugar, and a nitrogenous base.
What is the significance of the sugar-phosphate backbone in DNA?
The sugar-phosphate backbone provides structural support and stability to the DNA molecule.
What is the function of hydrogen bonds in the DNA double helix?
Hydrogen bonds connect the nitrogenous bases of the two DNA strands, holding the double helix together.
What are the four nitrogenous bases found in DNA, and how are they abbreviated?
The four nitrogenous bases in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G).
What is the role of the nitrogenous bases in the structure of DNA?
The nitrogenous bases form the rungs of the DNA ladder and are responsible for base pairing between the two strands.
What does the term 'double helix' refer to in DNA structure?
Double helix refers to the two intertwined strands of DNA that spiral around each other.
What is the importance of the directionality (5' to 3') in DNA strands?
The directionality is important for processes like DNA replication and transcription, which depend on the orientation of the strands.
Why is the discovery of the DNA double helix considered a milestone in biology?
The discovery explained how genetic information is stored, replicated, and passed on, forming the foundation for modern genetics.