The same pre-mRNA transcript can be alternatively spliced to produce two different forms of an antibody protein; either the formthat is anchored in the cell membrane before an infection or the form that is secreted from the B-cell during an infection.The antibody gene contains 8 exons. The functions of the various exons encoded by the antibody transcript are listed below Exon1 – encodes a signal peptide, this peptide is removed after translation. This signal peptide helps direct the antibodyprotein from the rough ER (where it is made) to the Golgi apparatus. Exon 2 – codes for a part of the antibody protein that recognizes a particular antigen Exons 3 – 6 encode the constant region of the antibody. This is the part of the antibody that is the same in differentantibodies recognizing different pathogens. Exons 7 – 8 – encode a transmembrane region of the protein that anchors the antibody in the B-cell membrane.For the antibody mRNA, use the following colors to represent the various exons: Exon 1 – Red Exon 2 – Orange Exon 3 – Yellow Exon 4 – Green Exon 5 – Blue Exon 6 – Purple Exon 7 – Pink Exon 8 – Black1) Draw and title the complete pre-mRNA strand as it would have been transcribed from the antibody gene. Draw introns andexon boxes as large or as small as you would like, however please be sure to separate each exon with an intron and rememberthat introns are usually much larger than exons. Please use the correct color for each exon. Then, provide a description of thefunction of each exon in the antibody transcript.2) Pretend you are a spliceosome and construct the mRNAs described below by removing the introns and exons that will not beincluded.a) mRNA 1: In resting B-cells the antibody mRNA contains all 8 exons. Using the correct colors, draw a diagram representingthis mRNA. Be sure to give you diagram a title. Then, answer the following questions in complete sentences:i) What is the function of the protein produced from mRNA 1?ii) In what type of cell and when is this mRNA generated?b) mRNA 2: Once the B-cell has bound an antigen, it wants secrete antibodies against that antigen. Now the transcript isspliced so that only exons 1-6 are included. Using the correct colors, draw a diagram representing this mRNA. Be sure togive you diagram a title. Then, answer the following questions in complete sentences:i) What is the function of the protein produced from mRNA 2?ii) In what type of cell and when is this mRNA generated?

In this drawing of a primary transcript from a T-cell Receptor gene, the exon labeled ______ will code for the part of the protein in contact with the cytosol, the exon labeled _____ will be removed during splicing and the exon labeled ______ will wind up in the lumen of the ER. The primary transcript shows, from the left, a black rectangle (L), an intron, a pink rectangle(V), a yellow rectangle(J), and intron, another yellow rectangle, a large blue rectangle (C), a smaller blue rectangle (XC), a brown rectangle (TM) and a small blue rectangle (CA).1 pointCA; J; VCA; L; CTM; J; CTM; L; VXC; J; VXC; L; C

A cell makes a protein that it releases into the extracellular environment. Which best describes the sequence from synthesis to exocytosis? Golgi apparatus → rough endoplasmic reticulum → plasma membrane Nucleus → ribosome →smooth endoplasmic reticulum → plasma membrane Rough endoplasmic reticulum → Golgi apparatus → plasma membrane Rough endoplasmic reticulum → lysosome → plasma membrane Smooth endoplasmic reticulum → Golgi apparatus → plasma membrane

In eukaryotes, exons are sequences that are A. Uitgesny word uit die mRNA voor transkripsie / Excised from the mRNA prior to transcription B. Getransleer word na proteïene / Translated into proteins C. Getranskribeer word maar nie getransleer nie / Transcribed but not translated D. Nie een van bogenoemde nie / None of the above

The image shown here is an illustration of a eukaryotic protein-coding gene, emphasizing theregulatory sites involved in its expression. The grey boxes code for exons and the letters indicateselect regions of the gene. Use this illustration to answer the next 2 questions (Q36 & Q37).[Hint: Since this is a gene, the image is depicting DNA sequence, not pre-mRNA sequence – don’tget confused]36. Which of the following statements is correct?1. The TATA box can be found at point A.2. The ATG sequence can be found at point B.3. The sequence NCAGG can be found at point C.4. The sequence TAA, TGA or TAG can be found at point E.A. 1, 2 and 3B. 1 and 3C. 2 and 4D. 4 onlyE. All of 1, 2, 3 and 4 are correct

Arrange the following events in the correct sequence.(1) A protein moves through ER and then is carried in vesicles to the Golgi apparatus.(2) A vesicle pinches off from the Golgi apparatus and carries material to the cell membrane.(3) The Golgi apparatus modifies the protein and then packages it into a vesicle.(4) A protein is made by ribosomes on the rough ER.Multiple Choice4, 1, 3, 22, 3, 1, 44, 3, 2, 13, 2, 4, 11, 2, 3, 4