Biochemistry module 1 quiz.

Biochemistry C785 Module 1 Quiz 1. One strand of chromosome 2 has a DNA sequence that consists of this: 5'- AAG CGG TAC GTA -3'. What will be the sequence of the complementary DNA strand? a. 5’- TAC GTA CCG CTT -3’ Correct! This is the complementary sequence written in the 5' to 3' direction. 2. A woman is homozygous for an abnormal gene on Chromosome 2 that codes for an autosomal dominant disease. This means that she: a. Will have the disease Correct! The disease would be expressed with a single copy of the mutant in an autosomal dominant disease, but two copies (homozygous) would mean that all her children would inherit the disease as well. 3. A man and a woman, BOTH with the blood type O, have four children. What will be the blood types of their children? a. b. 100% Type O CorrectCorrect. To have an O blood type, you must be homozygous for O. Both parents would have only the O gene to pass onto their children and thus all children would have type O blood as well. 4. A couple has six children, 4 girls and two boys, all of whom have prominent chin dimples. If only the mother has a prominent chin dimple, what is the likely inheritance pattern for chin dimples? a. Autosomal dominant Correct! If only one parent has a trait and then all the children have the trait, the trait must be dominant. There was only one dominant pattern listed. 5. This pedigree displays what inheritance pattern? a. Sex-linked dominant Correct! There are no carriers, meaning this is a dominant pattern. there is also gender flipping with the affected individuals in the next generation (ie an affected father having an affected daughter and an unaffected son). 6. A son with Tay Sachs disease was born into a family. What can you determine from the small family pedigree below? a. II. Sex-linked recessive is a possibility b. III. Autosomal recessive is a possibility 7. Which of the following statements about epigenetics is false? a. The DNA sequence is permanently altered. CorrectCorrect! This is a false statement that would be referring to a mutation. b. Access to the promoter region of a gene by transcription factors is affected. c. Gene expression is influenced by chemical modifications of the DNA and/or histone proteins. d. Environmental stimuli control gene expression. 8. Red green colorblindness: a. Is due to a mutation in the opsin gene CorrectCorrect! The opsin gene is used for the production of the photoreceptor proteins that allow us to see and distinguish light. A mutation in the gene can lead to an inability to distinguish red light and green light. 9. The LCT gene codes for Lactase, which is responsible for the breakdown of lactose. Which of the following statements could explain how Lactase activity is increased? a. The presence of lactose causes nucleosomes to separate, exposing the LCT gene. CorrectCorrect! When the nucleosomes separate, this makes the unbound area available for gene expression. This study source was downloaded by from CourseH on :07:10 GMT -05:00 10. Histone proteins can be chemically modified by addition of a methyl group. As a result, nucleosomes pack _________ and the process of ___________ is decreased at those DNA sites. a. d. tightly, transcription CorrectCorrect! Methylated nucleosomes pack more tightly together, making their wound DNA less available for transcription. 11. When the wrong nucleotide is added to a newly for