BS 161 Final Exam Questions with Complete Solutions (Latest 2025) In yeast signal transduction, the yeast cells A)secrete molecules that result in response by other yeast cells.B)must physically and directly interact.C)produce signal molecules that change themselves so they can interact with one another.D)produce response molecules that diffuse to other yeast cells.E)mate, after which the new cells secrete hybrid signals. - Correct Answers ✅A Which of the following is true for the signaling system in an animal cell that lacks the ability to produce GTP?A)It would employ a transduction pathway directly from an external messenger.B)It could activate only the epinephrine system.C)It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.D)It would use ATP instead of GTP to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.E)It would be able to carry out reception and transduction but would not be able to respond 1 / 4
BS 161 Final Exam Questions with Complete Solutions (Latest 2025) to a signal. - Correct Answers ✅C Because most receptors are membrane proteins, which of the following is usually true?A)They open and close in response to protein signals.B)They change their conformation after binding with signal polypeptides.
C)They are only attached to one membrane surface: exterior
or interior.D)They preferentially bind with lipid or glycolipid signal molecules.E)They lead to changes in intracellular ion concentration. - Correct Answers ✅B Since steroid receptors are located intracellularly, which of the following is true?A)The receptor molecules are themselves lipids or glycolipids.B)The steroid/receptor complex can cross the nuclear membrane.C)The receptor molecules are free to move in and out of most organelles.D)The unbound steroid receptors are quickly recycled by lysosomes.E)The concentration of steroid receptors must be relatively high in most cells. - Correct Answers ✅B 2 / 4
BS 161 Final Exam Questions with Complete Solutions (Latest 2025) The receptors for a group of signaling molecules known as growth factors are often A)cyclic AMP.B)ligand-gated ion channels.C)neurotransmitters.D)receptor tyrosine kinases.E)G protein-coupled receptors. - Correct Answers ✅D Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of ions on opposite sides of the membrane?A)phosphorylated receptor tyrosine kinase dimer B)ligand-gated ion channel C)G protein-coupled receptor D)intracellular receptor E)receptor tyrosine kinase - Correct Answers ✅B If an adult person has a faulty version of the human analog to ced-4 of the nematode, which of the following is most likely to result?A)activation of a developmental pathway found in the worm but not in humans B)webbing of fingers or toes 3 / 4
BS 161 Final Exam Questions with Complete Solutions (Latest 2025) C)a form of cancer in which there is insufficient apoptosis D)neurodegeneration E)excess skin exfoliation - Correct Answers ✅C A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?A)an increase in cytosolic calcium concentration B)an increase in receptor tyrosine kinase activity C)lower cytoplasmic levels of cAMP D)a decrease in G protein activity E)a decrease in transcriptional activity of certain genes - Correct Answers ✅E Which of the following is a correct association?A)GTPase activity and hydrolysis of GTP to GDP B)adenylyl cyclase activity and the conversion of cAMP to AMP C)phosphorylase activity and the catabolism of glucose D)phosphodiesterase activity and the removal of phosphate groups E)kinase activity and the addition of a tyrosine - Correct Answers ✅A
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