C) Two strands of nucleotides held together by hydrogen bonds and formed into a double helix
100
Adenine and guanine are two-ring structures called ______, whereas cytosine and thymine are single ring structures called _______.
purines, pyrimidines
100
At the ends of chromosomes, repeating DNA sequences make up the _________.
telomeres
100
The double helix shape of DNA was first seen in [x-rays.]
TRUE OR FALSE. If false, change the part in the [brackets]
True
100
A strand of RNA and a strand of DNA each contain the same three types of nitrogen-containing bases; in addition, DNA has the base [thymine] which is not found in RNA.
TRUE OR FALSE. If false, change the part in the [brackets]
True
200
The bonding pattern of the two DNA strands have:
D) purines bonding to pyrimidines
200
The only nucleic acid to contain the base uracil is _____.
RNA
200
A covalent bond is formed when two atoms ______ a pair of electrons; this electron sharing does not occur in _______ bonds.
share, hydrogen
200
A Nobel Prize was awarded to [Franklin and Miescher] for their contributions to a description of the structure of DNA.
TRUE OR FALSE. If false, change the part in the [brackets]
False; Watson, Crick, and Wilkins
200
Referring to the two ends of a DNA molecule as the 5' end and the 3' end is a shorthand way of indicating that each end [begins with the same kind of molecule.]
TRUE OR FALSE. If false, change the part in the [brackets]
False; is chemically different
300
The difference between a covalent bond and a hydrogen bond is:
D) hydrogen bonds are more easily broken than are covalent bonds
300
A nucleotide is composed of a five-carbon ______, a phosphate group and a nitrogen- containing _________.
sugar, base
300
The two strands of DNA are not identical to each other, but are called _________.
complimentary
300
Centromeres and their associated kinetochores are the site of attachment for [telomerase.]
TRUE OR FALSE. If false, change the part in the [brackets]
False; spindle fibers
300
When two nucleotides are bonded together, the pentose sugar of one molecule is joined with the [the pentose sugar] of the other nucleotide.
TRUE OR FALSE. If false, change the part in the [brackets]
False; phosphate group
400
What is meant by DNA replication being a semiconservative process?
A) the replicated DNA consists of one old strand and one new
400
A human chromosome could be described as a single long molecule of _______ wrapped around ______.
DNA, historne proteins
400
The enzyme that is responsible for linking DNA nucleotides together is called _______
DNA polymerase
400
The human genome consists of about three billion base pairs and [100,000] genes.
TRUE OR FALSE. If false, change the part in the [brackets]
False; 200,000-250,000
400
The two strands of a DNA molecule are held together with [covalent bonds.]
TRUE OR FALSE. If false, change the part in the [brackets]
False; hydrogen bonds
500
1)The replication of DNA occurs during:
Also!
2)Guanine is the complementary base to:
1) B- interphase
2) A- cytosine
500
1) The amount of adenine in a sample of DNA:
Also! 2) In the same sample (question above), the amount of adenine:
1) A- equals the amount of thymine
2) B- might be 20% of the total bases present in the DNA molecules
500
If one strand of a DNA molecule contains the base sequence AATGCCGAT, the other strand will have the base sequence __________
TTACGGCTA
500
A relative amounts of the four nitrogen-containing bases led Chargaff to the model that [A pairs with A or G and T pairs with T or C.]
TRUE OR FALSE. If false, change the part in the [brackets]
False; A pairs with T, and G pairs with C
500
Following replication a chromosome is composed of two sister chromatids. Each chromatid contains a DNA molecule. The DNA molecule in one chromatid [is the original DNA molecule that was in the pre-replication chromosome.]
TRUE OR FALSE. If false, change the part in the [brackets]
False; is made of one strand of the original DNA molecule