GCD 2024 Exam Questions with Correct Answers

GCD 2024 Exam Questions with Correct Answers Robertsonian Translocations - Answer-In Robertsonian Translocations the long arms of two acrocentric chromosomes have fused. 1/900 live human births display Robertsonian translocations One example of a Robertsonian translocation is Familial Down Syndrome DNA FISH on Familial Down Syndrome - Answer-Down Syndrome affects 1/700 births About 5% of Down Syndrome is Familial Down Syndrome (1/14,000 births) The translocation is always between chromosomes 14 and 21 50% lethal Result of Translocation producing Philadelphia Chromosome detected using FISH - Answer-this is 1-2 per 100,000 people Two RNA nucleotides can spontaneously undergo the reaction shown below because it is thermodynamically favored - Answer-RNA dinucleotide pyrophosphate RNA Polymer - Answer-We think that the road to life began with The RNA polymer RNA World - Answer-RNA world refers to a period on Earth in which RNA molecules, but not DNA or proteins, were replicating RNA would have carried out three key functions: 1. Information storage in its nucleotide base sequence 2. Self-replication by functioning as a ribozyme and using RNA as a template to make complementary RNA molecules 3. Catalytic activity 3.5 billion years ago, the earth was very volcanic which made the earth very acidic. RNA is stable under acidic conditions. Partial positive charges attract partial negative charges - Answer-The partial negative charges (d-) of oxygen and nitrogen attract hydrogens with partial positive charges (d+)Od-Hd+ These are called 'hydrogen bonds' Longer RNA molecules can also fold back and hydrogen bond with themselves if complementary sequences are available - Answer-Bulge Loop, Internal Loop, Multibranched junction, Stem Loop