Exam_1_ShortAnswerKey_809 - BIO 307D Exam 1 September 21,...

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1 BIO 307D Name: S H O R T A N S W E R K E Y Exam 1 September 21, 2009 Section II . Compare/contrast and define 4 of the following terms. Each answer is valued at 5 points. If you answer more than 4 of the following, your first 4 answers will be graded. If you write an answer and then decide that you do not want that answer to be graded, clearly draw a line through that answer page. [20 pts total] Note: Partial credit should be given. ribonucleotide and deoxyribonucleotide Both are building blocks used to make nucleic acids, RNA & DNA respectively. Both consist of a 5- carbon sugar (pentose sugar) to which are attached the following: a nitrogen-containing base [A, U, G, C for ribonucleotides and A, T, G, C for deoxyribonucleotides] on the Carbon-1; a hydroxyl [OH] on the Carbon-3; and a phosphate [PO4] on the Carbon-5. The difference between the 2 molecules is that ribonucleotides have a hydroxyl [OH] on Carbon-2, while deoxyribonucleotide has only a hydrogen [H] on Carbon-2. intron and exon Introns are segments of a gene that are removed from the pre-mRNA by splicing to remove ribonucleotides which do not encode a specified protein product. Exons represent the gene segments that are spliced back together at the level of RNA, resulting in a mRNA that will encode a specific protein. [Note: do not penalize students for not distinguishing that introns & exons represent DNA – it is enough at this point that they understand these are sequences removed or retained within an mRNA.] transcription and translation Transcription is the process of copying DNA code from a ssDNA into a ssRNA molecule (mRNA, tRNA, and rRNA are major products); process is carried out by RNA polymerase. Translation is the process of decoding mRNA into a polypeptide (protein) and requires ribosomes and tRNA carrying amino acids. trophozoite and cyst A trophozoite is the growing (metabolizing and replicating) form of protozoans. [I emphasized enteric protozoans, but other protozoans that are free living also have trophozoite stages.] A cyst is a dormant (differentiated) form made by some protozoans that is stable in the environment
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Exam_1_ShortAnswerKey_809 - BIO 307D Exam 1 September 21,...

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