Unit 7: Gene Expression

Transcription is the process by which the information stored in DNA is copied into __________.

RNA.

In eukaryotes, transcription occurs in the __________.

nucleus.

RNA polymerase reads the DNA template strand in the __________ direction.

3' to 5'.

During transcription, complementary RNA nucleotides are added to form __________.

mRNA.

The __________ is a modified guanine nucleotide added to the 5′ end of mRNA.

5’ Methyl Cap.

The __________ is a sequence where RNA polymerase binds to initiate transcription in an operon.

Promoter.

The mRNA molecule undergoes __________, where introns are removed and exons are joined.

splicing.

Translation occurs in the __________ and involves ribosomes.

cytoplasm.

The ribosome binds to the mRNA at the __________ codon, which is usually AUG.

start.

tRNAs bring specific __________ to the ribosome during translation.

amino acids.

The first amino acid in the protein synthesis process is __________.

Methionine.

An organism’s __________ is the set of genes it carries.

genotype.

The __________ is the observable expression of the genetic instructions.

phenotype.

Changes to one nucleotide in the DNA sequence are called __________ mutations.

point.

__________ mutations result in a different amino acid sequence.

Missense.

When nucleotides are inserted or deleted and not in multiples of three, it results in __________ mutations.

frameshift.

The protein structure that binds to DNA sequences to enhance or repress transcription are called __________ factors.

transcription.

In operons, __________ molecules can bind to repressors to allow transcription to occur.

inducers.

The __________ operon is regulated by the presence of lactose in E. coli.

Lac.

In a repressible operon, gene expression is typically __________ by default.

on.

Differential gene expression allows cells to selectively activate or __________ specific genes.

repress.

Reverse transcriptase allows viruses to convert RNA into __________.

DNA.

The lack of proofreading activity in reverse transcriptase results in a __________ mutation rate.

high.

The process by which viruses hijack the host cell machinery to replicate is called __________.

biosynthesis.

The high mutation rates of reverse transcriptase help the virus to evade __________ recognition.

immune.

This structure in the mRNA protects it from degradation in the cytoplasm: __________.

Poly-A-Tail.

During translation, the ribosome reads mRNA in groups of three nucleotides called __________.

codons.

In eukaryotic cells, mature mRNA exits the nucleus after processing, which includes __________.

RNA splicing.

The __________ provides a regulatory sequence near the promoter where regulatory proteins bind.

operator.

Silent mutations have __________ change in the amino acid sequence.

no.

The accumulation of folding defects in proteins can reduce a protein's ability to evolve a new __________.

phenotype.

Highly expressed proteins may be less evolvable as they can tolerate more genetic __________ that cause folding defects.

variants.

Asymmetric cell division leads to distinct __________ fates in daughter cells.

developmental.

In inducible operons, the presence of an inducer molecule activates gene expression often associated with __________ pathways.

catabolic.

The __________ operon is often repressed by the presence of tryptophan in the cell.

TRP.