Question
I'm having a hard time with my exam. I would love some help. they are multiple choice. please help with every question and why it's the answer.
25. In the lac operon, lactose is a(n) that causes an allosteric change in the repressor protein. a. inducer b. regulator c. regulon d. activator initiator 26. A mutation occurs in the lacY gene of the lac operon. The mutation causes the corresponding permease protein to be nonfunctional. What effect will this have on the cel? a. It will not be able to cleave lactose into glacose and galactose. b. It will not be able to transport lactose across the cell membrane. e. It will not be able to pump out sugars when they reach too high of a concentration. d. It will not be able to make a repressor protein. e. all of the options are correct 27. For bacterial genes under positive control, transcription does not occur (or happens at very low levely until a binds to a. inducer b. regulator c. regulon d. activator e, initiator 28. Many proteins have to be activated by chemical modification (sach as the addition of a phosphate group)to finction. This is an example of a. transcriptional control b. RNA processing c. pre-translational control d. translational control e. post-translational control 29. Glacose levels affect regalation of the Jac operon. When glucose levels are cAMP binds to CAP which is an of the lac Operon. a. high.... activator b low.... activator d. low.... repressor 30. When the bacteria Fibrio cholera resides in the human gut they produce an activator protein that triggers the simaltaneous expression of at least 13 genes/operons that cause diarthea. This is an example of a. global gene regulation b. constitutive gene c, translational control d. negative control e. none of the options are 31. Which of the following is not a mechanism of chromatin remadeling: e. all of the options are . DNA methylation b. Histone modification e. Chromatin-remodeling d. Altermative spicing level of methylation and the chromatin will be complexes 32. Actively transcribed genes will have are enzymes that add acetyl groups to positively charged amino acids of histones and cause chromatin to HArs (histone acetyltransferases) condense a. HDACs...decondense chromosomal inheritance n pass on its patterns of DNA methylation and histone acetylation to its daughter cells. This is an exampe c. epigenetic inheritance d. DNA inheritance 34. A liver cell can pass on its patterns of DNA methy lation and histone acetylation to its a. Transient inheritance b. Passive inheritance
Explanation / Answer
Q25:- Option A
Explanation:- Lactose is an inducer that causes expression of lac operon.
Q26:- Option B
Explanation:- It will not be able to transport lactose across cell membrane because lacY codes for permease enzyme that functions as symporter in plasma membrane that transporta lactose inside cell.
Q27:- Option D
Explanation:- Activator must bind to DNA in case of postive control transcription.
Q28:- Option E
Explanation:- During completion of translation proteins undergo post translational modification to become functional.
Q29:- Option B
Explanation:- When glucose level low cAMP binds CAP which is an activator. This is called catabolite repression or glucose effect
