cell biology revision

What distinguishes rough endoplasmic reticulum from smooth endoplasmic reticulum?

• Protein packaging
• Synthesis of lipids
• Lack of ribosomes
• Presence of ribosomes

Which of the following cell organelles is called the powerhouse of the cell?

• Nucleus
• Lysosomes
• Chloroplast
• Mitochondria

Which of the following cell organelles is absent in prokaryotic cells?

• Nucleus
• Lysosome
• Endoplasmic Reticulum
• All of the above

What process occurs before the other?

• Transcription and then Translation
• Translation and then Transcription
• Transcription and then Ionization
• Translation and then Polymerization

Ribosomes need mRNA and tRNA to help complete translation. Which statement correctly describes their roles?

• tRNA builds the ribosome, while mRNA translates the nucleus into a protein.
• mRNA helps the tRNA translate the ribosome into a protein.
• tRNA translates the code in the mRNA into a string of amino acids.
• Ribosomes build tRNAs, which are translated into mRNA messages.

A researcher is analyzing a protein that is found on the plasma membrane. What can be concluded about the translation of this protein? I. It was translated on a cytoplasmic ribosome II. It involved the use of all three types of RNA III. It involved a polymerase enzyme

• III only
• II only
• I and II
• II and III

What amino acid is found in all proteins that have just completed translation?

• Phenylalanine
• Valine
• Cysteine
• Methionine

__________ are parts of __________ molecules that do not contain information about a protein's primary structure.

• Introns . . . pre-mRNA
• Exons . . . pre-mRNA
• Introns . . . mRNA
• Exons . . . mRNA

In eukaryotes, which of the following is true about introns and exons?

• The mature mRNA transcript contains a mix of introns and exons.
• Intronic regions typically code for transcription factors.
• Exons are repeating sequences that are typically found at the distal ends of a gene.
• The mature mRNA transcript only contains the introns because the exons have been spliced out.
• The primary RNA transcript contains both intronic and exonic regions.

If a gene produces a pre-RNA that is 1200 basepairs long and has the following intron-exon structure: Exon 1 - 200 bp Intron 1 - 100 bp Exon 2 - 50 bp Intron 2 - 150 bp Exon 3 - 700 bp How many basepairs long would we expect the mRNA to be?

• 950 basepairs
• 1150 basepairs
• 1000 basepairs
• 250 basepairs
• 500 basepairs