AP Biology
Saturday Study Session 2
Information Transfer
Student Packet
Session 1 – Cell Signaling, Endocrine, Thermoregulation
Multiple Choice Questions
1)What is the correct order for the following events in the interaction of a cell with a ligand signal molecule?
- Alteration of cell function
- Signal binds to receptor protein
- Signal molecule released from source
- Conformational shape change leads to signal transduction
A)1234
B)2314
C)3214
D)3241
2)Cell membranes are selectively permeable structures separating the exterior of a cell from the interior of a cell. Many signal transduction pathways use secondary messengers to:
A)Transport a signal through the lipid bi-layer portion of the plasma membrane.
B)Relay a signal from the outside to the inside of the cell.
C)Rely the message from the inside of the membrane throughout the cytoplasm.
D)Amplify the message by phosphorylating proteins.
3)Which of the following signal molecules pass through the plasma membrane and bind to intracellular receptors that move into the nucleus and function as transcription factors to regulate gene expression?
A) testosterone, a steroid hormone
B)growth factors or other proteinous molecules
C)epinephrine
D)neurotransmitter released into the synapse between nerve cells
4)The human body produces numerous hormones to help regulate homeostasis. Which of the following is NOT an accurate statement?
A)Hormones are chemical messengers that travel to target cells through the circulatory
system.
B)Hormones of the same chemical class usually have the same function.
C)Hormones are often regulated through feedback loops.
D)Hormones often regulate homeostasis through antagonistic functions.
5)Homeostasis can basically be thought of as “trying to stay within the limits of life”. There is an upper and lower limit. Life exists in-between those limits and constantly approaches each limit. An example of antagonistic hormones helping to control homeostasis and prevent going past the limit is:
A) Thyroxine and parathyroid hormone in blood calcium balance
B)Oxytocin and prolactin in milk production
C)Insulin and glucagon in glucose metabolism
D)Progesterone and estrogen in sexual differentiation
6)Thermoregulation is an essential concept for understanding organisms survival abilities in an changing environment. Environments get cold or hot depending upon the season or location. Which of the following is the BEST example of an effector’s response in negative feedback?
A)An increase in body temperature resulting from shivering.
B)An increase in body temperature resulting from exercise.
C)An increase in body temperature resulting from exposure to the sun.
D)An increase in body temperature resulting from fever due to infection.
Math Grid In
A hospital supply room is out of saline drip bags. A nurse is asked by a doctor to make 1 L of a 0.05 M saline solution for a patients emergency IV drip. In the stock room she finds uniodized salt. Reverting back to her days in AP Biology and AP Chemistry, she remembers how to make the solution. She carefully weighs out 58.5 grams of NaCl (the formula weight of NaCl). She then adds 1000 mLs of distilled water. This provides her with a 1.0 M saline solution. If the nurse wishes to make make the 0.05 M solution and save the extra as emergency stock, how much saline solution will she need to measure out in a graduated cylinder to dilute the 1.0 M solution to 0.05 M by adding distilled water?
Perform calculations here:
Short Free Response
1)Organisms use various methods for regulating homeostasis. Two common methods are negative feed back loops and positive feedback loops. Explain what is meant by a positive feedback loop and a negative feedback loop. For each give one specific example within the human body.
2) Cell signaling is an important component of being a multi-cellular organism. Cell signaling has three components: Reception, Transduction, Response. Explain the process of cell signaling by describing what is occurring in each part..
Long Free Response
- Homeostatic maintenance of optimal blood glucose levels has been intensively studied in vertebrate organisms.
.(a) Pancreatic hormones regulate blood glucose levels. Identify TWO pancreatic hormones and describe the effect of each hormone on blood glucose levels.
.(b) For ONE of the hormones you identified in (a), identify ONE target cell and discuss the mechanism by which the hormone can alter activity in that target cell. Include in your discussion a description of reception, cellular transduction, and response.
.(c) Compare the cell-signaling mechanisms of steroid hormones and protein hormones.