UGA Biology 1107 Unit 2 Dees TopHat/Quiz Questions

Order from Largest to Smallest

- Gene, Chromosomes, Nucleotide, Terminator

Chromosome > Gene > Terminator > Nucleotide

T/F Both strands of DNA are used as templates during replication, while only one strand is used to transcribe a gene

True

Which process would be directly affected by a substance that interferes with splicesomes?

mRNA Processing

- Splicing occurs during processing, and Processing would be DIRECTLY effected. Translation and proteins would also be effected but not as directly as processing

How many chromosomes are in a cell that contain 20 chromatids?

10

- Chromatids are the replicated strands of DNA

For every 1 chromosome is 2 chromatids

T/F Mutations always have an effect on protein function and lead to disorders

False

- Silent mutations have no effect and other point mutations can be neutral or beneficial

Which models of replication predicted a single DNA band after one replication during the Meselson and Stahl experiment?

Dispersive (all hybrids throughout all rounds)

Semiconservative (all hybrids after first round)

Replicated _______ are made of ______ and consists of two ________

Chromosomes, chromatin, chromatids

Replicated ____ consist of two _____ and are made of _____

Chromosomes, chromatids, chromatin

What is chromatin?

DNA and protein that are tightly coiled around proteins call histones.

Which of these mechanisms can regulate gene expression in a eukaryote?

1. Alternatively splicing the exons in mRNA

2. Signal from other cells to the environment

3. Protein modifications after translation

4. Enable or block transcription of genes

1, 2, 3, 4

If 3’- TACCTGATG-5’ codes for amino acids and underlined nucleotide changes to an A, what type of mutation is this?

Silent

- No change in amino acid

How did Matthew Meselson and Franklin Stahl keep track of teh original DNA during their replication experiment?

isotopes

How many chromosomes are in a cell that contain 40 chromatids?

20

Which replications model predicted two bands after one round?

Conservative

Which of these can regulate gene expression in prokaryotes?

1. Alternatively splicing the exons in mRNA

2. Signal from other cells to the environment

3. Protein modifications after translation

4. Enable or block transcription of genes

2, 3, and 4. NO SPLICING bc no exons goes straight to translation after transcribing

Which process would be directly effected by a substandard that interrupts RNA Polymerase ?

Transcription

Primase

An enzyme that makes short pieces of RNA that will enable DNA replication to begin

Telomerase's

Prevent the shortening of chromosomes during replication in eukaryotic cells.

- Not found in prokaryotes

- Found on the LAGGING strand

DNA ligases

Removes RNA primers by catalyzing the last bond between nucleotides.

- On the lagging strand

Toposiomerase

enzyme that unwinds DNA during DNA replication. breaks up parts of the backbones of DNA temporarily (sugar phosphate backbone)

- essential for replication

Helicase

Break hydrogen bonds to separate anti parallel strands of DNA molecules

- NOT found in PCR

How are leading and lagging strands different during replication?

Lagging strands are built in fragments, and leading are made continuously

Lagging strands are read 5' > 3'

Leading Strands are read 3' > 5'

What enzyme performs reverse transcription?

Telomerase

- Has own RNA template to place DNA nucleotides on 3' end of a lagging strand

Limitations of DNA polymerase

- Only begin replication if primer is present

- Only read template strands in on direction (3' to 5')

- Only build new strands by adding to the 3' end

Where are genes transcribed ?

Inside a cell

Which biological molecules are found in chromatin of eukaryotic cells?

1. Sugars

2. Nucleotides

3. Nucleic Acids

4. Amino Acids

5. Proteins

1, 2, 3, 4, & 5

Chromatin is the DNA and protein in a eukaryotic cell

Assume that a replication fork moves about 800 base pairs per second in bacteria. How long will it take an E. coli bacterium to replicate its DNA, which is circular and has 4.6 million base pairs?

48 minutes

Why must replication of the lagging strand be different than the leading strand?

Strand must go in the other direction

Which of the limitations apply to both DNA polymerase and RNA Polymerase?

1. Build strand in 5' to 3' direction

2. Use four nucleotides to build

3. Build new strands by adding to 5' end

4. Start by adding to existing nucleotides

5. Read templates 3' to 5'

1, 2, 5

3. Add to 3' end

4. RNA polymerase does, but DNA polymerase requires a primer

Error rate in human DNA replication

One error per billion base pairs