Genetics: Unit 2

Sugar: Deoxyribose (in DNA)

Sugar: D-Ribose (in RNA)

Purine: Adenine (in RNA)

Purine: Guanine (in RNA)

Thymine (in DNA)

Cytosine (in both DNA & RNA)

Uracil (in RNA)

Purine

Nine-member double ring, is a kind of base, examples are Adenine & Guanine

Pyrimidines

Six-member single ring, is a kind of base, examples are Cytosine, Thymine, and Uracil

What is this?

Phosphate group

DNA contains:

deoxyribose

RNA contains:

ribose sugar

DNA and RNA are types of:

Nucleic acids

Nucleotides

building blocks of nucleic acid

DNA A box is:

a DNA sequence that is bound by DNA A protein

Elongation

What is the red?

RNA Primers

What is the purple?

DNA Strands

What is the blue?

New synthesized DNA strands

What is the red?

RNA Primers

What is the blue?

New synthesized DNA strands

What is the pink?

Template DNA strands

What is beige?

Clamp loader complex

What is the purple?

Subunits/linkers

One difference between eukaryotic and prokaryotic DNA replication is that:

Eukaryotes have multiple ori on each chromosome

Telomere

DNA sequence found at the ends of linear chromosomes

Telomerase adds nucleotides to the:

3' overhang so there is a place for a complementary primer to base pair with this strand

DNA

Bacterial genomes are:

RNA or DNA

Viral genomes are:

Bacterial Chromosomes

Circular, double-stranded D N A compacted into nucleoid. Not surrounded by a

membrane

Naked DNA

The simple double-helix structure with a width of approximately 2 nm.

DNA packaged in nucleosomes

DNA wraps around histone proteins to create a "beads-on-a-string" structure (~11 nm wide)

30nm fiber

The nucleosome chain coils tighter into a more condensed helical filament (~30 nm wide).

Metaphase chromosomes

During cell division (mitosis), the chromatin undergoes maximum compaction and supercoiling to form discrete, highly dense chromosomes (~1,400 nm wide) so they can safely separate.

Polymerase chain reaction (PCR)

Making lots of copies of a DNA sequence

Sequencing DNA

Determining the order of A, G, C, T in a sequence

Denaturation

DNA strands separate

Annealing

Primers bind to DNA

Synthesis or primer extension

Polymerase copies the target sequences

far apart

Crossing over is more likely to occur between genes that are ________ on a chromosome.

linkage group

Another name for a chromosome is a ________, since it contains genes that are often inherited together.

protein

In the Hershey and Chase experiment designed to determine the molecule of heredity, what was radiolabeled with ³⁵S?

23.6% of the offspring exhibit recombination between the two genes.

A map distance of 23.6 between two genes indicates which of the following?

mitotic recombination

In heterozygous individuals, loss of a wild type allele can occur rarely during development by

Hershey and Chase

These individuals determined that DNA was the genetic material in T2 phage.

phosphorus

What radiolabeled substance did Hershey and Chase use to label the DNA component of the bacteriophage in their study to determine whether protein or DNA was necessary for phage production?

The bacteria were in the pellet, many of which contained the radioactive viral DNA.

In the classic experiment conducted by Hershey and Chase, why was the pellet radioactive in the centrifuge tube that contained bacteria with viruses?

Avery, Macleod, and McCarty

The individuals who determined that Griffith's transforming principle was DNA were ________.

antiparallel

The fact that the strands of the DNA helix are arranged in opposite directions gives DNA its ________ characteristics.

Hydrogen

________ bonds are responsible for the chemical affinity between A and T (or G and C) nucleotides.

the five-carbon sugar it uses

DNA differs from RNA in which way?

40%

According to Chargaff's rule, if the DNA of a species contains 10% adenine, what percent of guanine will it contain?

phosphodiester bonds

The backbone of the DNA molecule is formed by ________.

1

How many origins of replication are there in a bacterial chromosome?

conservative

The first generation of replication in the Meselson and Stahl experiment disproved which theory of replication?

semiconservative

DNA replication occurs through a _________process.

After both the first and second generation, they would have observed a band of DNA in between the ¹⁵N and ¹⁴N bands.

When Meselson and Stahl performed the experiment that showed that replication is a semiconservative process, they utilized E. coli, and various isotopes of nitrogen (¹⁵N and ¹⁴N). What would have been their results  if DNA replicated dispersively?

The amphibian has more repetitive sequences than the mammal.

What is one reason why an amphibian, such as a salamander, might have a larger genome than a mammal, such as a chimpanzee?

unique sequences

The majority of the nonrepetitive genes in an organism are found in which of the following?

Two turns of DNA wrapped around an octet core of histone proteins.

What is a nucleosome composed of?

naked DNA, nucleosome, 30 nm fiber, radial loop, metaphase chromosome.

The correct order of compaction from least compacted to most compacted would be

146

About how many bases of DNA wrap around a histone complex?

to form loop structure, to condense DNA, and to bind to the nuclear matrix

What is the purpose of MARs and SARs?

heterochromatin

Areas of the chromosome that are highly condensed and transcriptionally inactive are called

DNA is negatively charged and histones are positively charged.

Histones and DNA have a strong attraction for each other because

It cannot begin the 5' end of a new strand without a primer, It can only make new DNA in the 5' to 3' direction, and It can add nucleotides to the 3' end of a nucleotide chain

Which of the following is  true about DNA polymerase?

phosphodiester

During elongation of a polynucleotide, enzymes join the base's nucleotide to the preceding nucleotide by a(n) __________bond.

To allow DNA to be synthesized in the 5' to 3' direction on the lagging strand

What is the purpose of Okazaki fragments?

topoisomerase

What enzyme relaxes supercoiling ahead of the replication fork?

DNA ligase

Which enzyme attaches adjacent Okazaki fragments, forming a continuous DNA strand?

to the left

In the diagram below, which way does the pictured replication fork proceed?

4

In the diagram below, which DNA is being synthesized continuously?

5’

In the diagram below, what end of the DNA is at A?

64

If a single DNA molecule is amplified by PCR, how many DNA molecules will there be after six cycles?

nucleotide triphosphates that lack a 3' hydroxyl

In Sanger sequencing, what causes DNA synthesis to terminate at a specific base?

there is no place for primase to lay down a primer so DNA polymerase cannot replicate that area of the chromosome.

Telomerase exends the 3' ends of chromosomes because

at least some sequence information about the region to be amplified.

PCR cannot be successfully performed without

Short, repetetive DNA sequences found at the end of linear eukaryotic chromosomes.

What is the structure of telomeres?

remove an incorrect nucleotide that was accidentally just added during DNA replication

DNA polymerase III uses its 3' to 5' exonuclease activity to

two

How many replication forks depart from an origin of replication?