AP Bio Unit 6 Test

A silent point mutation...

codes for the same amino acid, polypeptide does not change

A nonsense point mutation...

terminates the chain (stop codon)

A missense point mutation...

produces a different amino acid

How do you know if DNA was transcribed to RNA?

U is present in the RNA code

What is tRNA?

transfer RNA that carries the amino acids to the ribosome via the anticodon

What makes up the backbone of a DNA strand?

sugar and phosphate

What type of structure is thymine?

pyrimidine, single ring

What type of structure is adenine?

purine, double ring

What type of structure is guanine?

purine, double ring

What type of structure is cytosine?

pyrimidine, single ring

Which type of RNA carriers information from the nucleus into the cytoplasm?

mRNA

Describe gene expression via chromatin modification.

DNA methylation condense chromatin by adding methyl groups to the dna

During electrophoresis, why does DNA move toward the positive electrodes?

phosphate group on DNA have a negative charge

What procedure amplifies DNA?

PCR

Describe the semi-conservative model of DNA replication.

Both parent strands are copied. The daughter molecules have one parental and one new strand

If scientists do an experiment that prevents DNA from replicating properly, making the strands re-bond after they are separated by helicase, what is most affected by the experiment?

helicase

Describe initiation during transcription in prokaryotic cells.

RNA polymerase can bind directly to DNA

Describe initiation during transcription in eukaryotic cells.

RNA polymerase must bind to transcription factors

On the leading strand, DNAP III transcribes in what direction?

same as helicase

How many primers are used in transcription of the leading strand?

only one

What direction does the leading strand elongate?

5' to 3'

What would you expect if a chemical altered eukaryotic mRNA so there is no 5' cap added?

less protein in the cell because it is easily broken down when it leaves the nucleus

Describe gene expression in prokaryotes.

transcription and translation happen in the same place at the same time, ribosomal subunits are smaller

Describe gene expression in eukaryotes.

transcription happens in the nucleus, translation happens in the ribosomes/cytoplasm, ribosomal subunits are larger

In eukaryotic development, what is the physical process that gives an organism its shape?

morphogenesis

What is an operon?

promoter, operator, and gene

Describe termination of translation.

stop codon in the mRNA reaches the A site of a ribosome and release factor will hydrolyze the bond that holds the polypeptide

The E. coli operon is considered an...

inducible operon

Why must the lagging strand elongate using Okazaki fragments?

DNA polymerase can only move in the 3' to 5' direction

How does point mutation affect an enzyme's activity?

may change an amino acid or terminate the chain early; reduces the enzyme's ability to function

Describe transformation.

bacteria uptake DNA from their surroundings

Describe conjugation.

if bacteria contain an F factor, it can transfer DNA to a nearby cell via its pilus. If it transforms the F factor to the bacteria, it turns into an F+ donor and makes its own pilus

Describe transduction.

a virus injects its DNA into a bacterial cell, sometimes the DNA from the bacteria is incorporated into the viral DNA

Which of the following does NOT represent a differnece between gene expression in prokaryotes vs eukaryotes?

b. prokaryotic RNA polymerase moves across the DNA in a 3 to 5 direction

5 cap will not be added

the scientist would expect to find less protein A in the cell because it would be more easily broken down when leaving the nucleus

APE

translation; elongation

which of the following best describes termination of translation

when a stop codon in the mRNA reaches the A site of the ribosome and release factor will hydrolyze the bond that holds the polypeptide bond

why do okazaki fragments form?

DNA polymerase can only move in the 3 to 5 direction

A section of DNA at the replication fork reads as follows: 3’- ACTGATCTAAGC -5’. Primase places an RNA primer starting at the underlined nucleotide. What would be the correct primer sequence?

5’- UAGAUUCG -3’

according to the figures, what does the araC regulatory gene produce and where does it bind?

the araC protein; binds to the promoter

what type of operon is shown in figures 2 and 3?

inducible operon

researchers experimenting w cancer drug that rebonds DNA strands, what is most likely to be affected?

SSBPs

transduction def

viral transmission of genetic material

conjugation def

cell to cell transfer of DNA

transpostion

movement of DNA segments within and between DNA molecules

transformation

uptaking of DNA from a nearby cell

which of the following does not represent a componet of operon

d. repressor

used to be alt splicing

a. transcription; elongation

process w boxes

alternative splicing

what gene would you expect to see DOWNSTREAM of the operator in figures 2 and 3?

pAMP

metastasis

The spread of cancer cells from the place where they first formed to another part of the body

how does cadherin 22 promote metastasis?

hypoxic cancer cells to stick together and migrate collectively as a group

propose and explain one possible mechanism for how adh 1 could target and reduce cadherin 22 levels in cancer cells

the cellular signaling pathway can be toyed with and lead to impact the downstream signaling pathways and messes w the growth of the cancerness

large scale changes

chromosmal

small scale

nucleotides subs, insertions, deletions