BIO 141 EXAM 3 CHAPTER 16 Exam Questions With 100% Correct Answers.

What is the modern definition of the term gene - The modern definition of gene refers to the inherited instructions for a particular trait. How does a gene specify the production of a protein - Gene contains DNA which lives in nucleus and uses the mRNA to transfer information outside the nucleus and to the ribosome where protein takes place Which of the steps in information flow within the cell involves the transcription of information? Which involves translation from one language to another? What are the principal enzymes and molecules involved in these processes? - In transcription: DNA>>>RNA In Translation: RNA>>>Proteins The principal enzyme involved is: RNA polymerase Molecules involved: Nucleotides and amino acids Is the "central dogma" truly dogma in science? Describe two exceptions to the central dogma - NO, it is not truly dogma in science The exceptions to dogma: Not all RNA molecules go through the process of translation; if they are not mRNA, they don't do the job Information from the RNA sometimes flows back to the DNA Explain the relationship between genotype and phenotype, and specifically describe the cellular process that links the two - The relationship between genotype and phenotype: The genotype is influenced by the base sequence of the DNA while phenotype is the product of the proteins How could a change in the base sequence of a gene lead to a change in the phenotype of an organism?Give two examples of how single amino substitutions can affect protein function and the phenotype of an organism - A change in the sequence that is, if there is a change of sequence base in DNA and RNA copies, its translation to proteins is what produces the phenotype therefore a change in DNA>>RNA process(gene) is a change in phenotype eg; In some individuals, hemoglobin has valine instead of glutamate and this causes the hemoglobin molecules to stick together another example is the difference in color or beach mice and mainland mice How can the 4 nucleotides present in DNA code for the 20 different amino acids found in proteins? How many bases would be needed in a codon if there were five RNA bases instead of four - This is done by understanding that 1 nucleotide codes for four amino acids, therefore 4 nucleotides would be= 4*4*4*4 = 64; anything less than 4 nucleotides codes for less than 20 5 RNA bases= 256 What is a reading frame and why is it important in translation - The reading frame is important because the addition or deletion of a base pair can cause a loss of function of a protein gene.