BIO 311 Walton Name: Practice exam:Exam 1 Multiple choice section: Gircle the le

Question

BIO 311 Walton Name: Practice exam:Exam 1 Multiple choice section: Gircle the letter of the best answer for each question. (2 pts each) 1. Which type of protein forms an open pore through the membrane only in response to a specific signal? a. Intracellular receptor b. Carrier protein c. Open channel d. Gated channel 2. All of the following are true of diffusion in the animal body except a Diffusion occurs more slowly at higher temperatures than at lower temperatures. b. Smaller molecules diffuse more quickly than larger ones c. Net movement of molecules occurs until the osmolarity is equal d. Diffusion is rapid over short distances and slower over longer distances 3. In a reflex pathway, an integrating center a is the disturbance or change that sets the pathway in motion. b. is an electrical and/or chemical signal that travels to the effector. c evaluates incoming signals and compares it with the setpoint. d. is the minimum stimulus that must be achieved to set the reflex response in motion. 4. Why do some normal cells fail to respond to a chemical signal? a. Chemical signals are only delivered to specific cells. b. Some cells lack the necessary receptors e. Some cells are completely without receptors d. Some cells are completely without ligands 5. Why is the resting membrane potential approximately -70 mV for most cells? a Most membranes are 40 times more permeable to K" than to No b. Most membranes are 10 times mere permeable to Na" than to K c. The large concentration of proteins in the interstitial space draws Na" out of the cell making it negatively charged. Most cells contain a large concentration of Cl making them negatively charged d. 6. Which type of transport generally requires that the molecule being transported is lipophilic? a Phagocytosis b. Exocytosis c. Simple diffusion d. Facilitated diffusion e. Primary active transport Assume a resting membrane potential of -70 mV. Which term would be used to describe a change in membrane potential from resting potential to-90 mV 7. a Depolarization D Hyperpolarization c. Repolarization d. Equilibrium potential

Explanation / Answer

Answers -

1. Gated channel.

2. Diffusion occurs more slowly at higher temperatures then at lower temperatures.

3. Is the minimum stimulus that must be achieved to set reflux response in motion.

4. Some cells are lack the necessary receptors.

5. Most membranes are 40 times more permeable to K+ then to Na+.

6. Simple diffusion.

7. Hyperpolarization.

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.