Gene Regulation

Which of the following is/are similarities between prokaryotic and eukaryotic gene expression?

• both use proteins to interact with the DNA to control gene expression

• both have histones complexed with their DNA

• both separate the processes of transcription and translation spatially

• all of the above

The human genome appears to have only about as many genes as the simple nematode worm, C. elegans. Which of the following best explains how the more complex humans can have relatively few genes?

• Human genes have unusually long introns involved in the regulation of gene expression

• More than one polypeptide can be produced from a gene by alternative gene splicing

• The human genome has a high proportion of noncoding DNA

• The human genome has a large number of SNPs (single nucleotide polymorphisms) which increases genetic variability

Tags

IST-2

In a catabolic pathway, an operon causes transcription of the genes controlling a group of enzymes.

• inducible operon

• repressible operon

• intron

• exon

Alternative RNA splicing involves

• removing introns and splicing the same exons together

• removing exons and splicing the same introns together

• removing introns and splicing different exons together

• removing exons and splicing different introns together

Scientists have concluded that gene expression is responsible for the differentiation of the cells of a multicellular organism. Which two observations together most strongly support this conclusion?

• All cells produce the enzymes needed for energy metabolism

• The DNA in each body cell of an organism is essentially identical

• Gene expression can be regulated by a wide variety of mechanisms

• Enzymes needed for digestion are made only be cell lining the digestive tract

Tags

NGSS.HS-LS1-1

NGSS.HS-LS1-4

Muscle cells differ from nerve cells mainly because they

• express different genes.

• contain different genes.

• use different genetic codes.

• have unique ribosomes

Tags

NGSS.HS-LS1-4

Why are insertion and deletion mutations so harmful?

• They change all of the codons from the mutation on down the line, which changes the amino acid sequence

• They insert things that an organism doesn't need.

• They often delete things that organisms need.

• Insertion and deletions are not any more harmful than substitution mutations.

Tags

NGSS.HS-LS3-2

What is an example of positive control?

• The lac operon being transcribed when lactose is present

• The trp operon being transcribed when tryptophan is absent

• the lac promoter being activated by CAP when cAMP levels rise

• control is all just an illusion

The "on/off" switch for an operon is called the

• promoter

• repressor

• operator

• gene

what is an operon?

• a part of a ribsome

• a part of a Rna

• a unit made up of linked genes that code for proteins needed to do a specific task

• needed for dna replication