Question

10.

10. When considering regulation of gene expression A. miRNA/RISC complex binding will lead to degradation of target mRNA. B. siRNA/RISC complex binding will halt translation of the target mRNA. C. proteins are destroyed by the proteasome using GTP energy D. labeling of proteins for destruction by the proteasome requires ATP energy 11. When comparing the epigenomes of normal and cancerous breast epithelial cells A. cancerous cells increase the methylation of genes that promote cell growth. B. cancerous cells increase the methylation of programmed cell death genes. C. normal cells increase the methylation of genes that promote DNA repair D. normal cells increase the methylation of genes that keep cell growth in check. 12. When examining the epigenetic patterns of DNA methylation across the chromosomes of identical twin pairs, A. younger twin pairs have a very different distribution of DNA methylation. B. younger twin pairs have many areas that are hyper and hypo-methylated. C. older twin pairs have very similar distribution of DNA methylation. D. older twin pairs will methylate and express most of their genes differently 13. When comparing individuals with lactase persistence to individuals who are lactose intolerant, A. individuals with lactase persistence have a mutation that arose randomly within the lactase gene that keeps if permanently on B. lactose intolerant individuals are able to metabolize lactose when they are born, but are not able to do so as well as they age C. lactose intolerant individuals are born without the ability to express the lactase gene D. lactose intolerant individuals have a mutation in the galactokinase gene 14. Probiotics are able to improve lactose digestion and eliminate symptoms of lactose intolerance because they A. modify the intestinal microbiome, and increase beta-galactosidase activity. B. stimulate endogenous lactase enzyme activity in the intestine C. reduce the amount of lactic acid producing bacteria in the intestine D. decrease the amount of lactose that is metabolized in the intestine. 15. The image below is a representation of the structure of the lactase gene. The final mature and functional lactase protein will be made up of which regions from this sequence? SS LCTa profragment LCT МА СТ A. the SS, LCTaprofragment, LCTBfinal, MA and CT regions. B. the SS, LCTaprofragment, MA and CT regions. C. the LCTBfinal, MA and CT regions. D. the SS, LCTBfinal and MA regions.

Answer 1

10)

• miRNA/ RISC complex silences the target mRNA.
• SiRNA/RISC degrades the mRNA
• Proteosome degradation proceeds by ubiqutination of the target protein .
• The ubiqutination is performed by adding ubiqutin molecules in the presence of ATP.
• Hence , option D is corrrect.

11)

• Methylation of genes stops translation of genes .
• If cancer cells increase methylation of genes that promote cell growth , then cell growth will not take place. But in cancer cells cell growth proliferation is continuous.
• Normal cells decrease methylation, of DNA repairing cells so that DNA repair occurs.
• Normal cells decrease methylation of cells that keep cell growth in check
• So cancerous cells increase methylation of programmed cell death genes so that damaged cells are not degraded. This property is found in cancerous cells,
• Hence option B is correct.

12)

• DNA methylation in epigenetic patterns becomes dissimilar with increasing age.
• So, epigenetic pattern will be similar in younger monozygotic twins than older twins.
• Hence , option b is correct.

13)

• Lactose intolerant individuals are able to metabolise lactose in infant stages and lost that ability when they growup.
• Thus, option b is correct.

14)

• Pre-biotics when taken , increases the beta galactosidase concentration in the intestine by break down of cell walls of the bacterial cells.
• So, the concentration of beta galactosidae is altered .
• Hence option a is correct.

15)

• Option A is correct
• It contains ss, Pro region , mature region , A and C region.