Which of the following molecules cannot pass through the plasma membrane?

Here are the solutions to the questions from the image you sent. Question 8: Which of the following molecules cannot pass through the plasma membrane? The plasma membrane is selectively permeable. Small, non-polar, and lipid-soluble molecules can pass through easily. Large, charged, or polar molecules generally require transport proteins. Amino acid-based hormones are typically large, polar molecules that cannot directly diffuse across the lipid bilayer. A. water molecules - Can pass (osmosis, aquaporins). B. non polar molecules - Can pass easily (e.g., O\(_2\), CO\(_2\)). C. amino acid based hormones - Generally too large and/or polar to pass directly. D. fat-soluble molecules - Can pass easily (e.g., steroid hormones). The correct option is C. C. amino acid based hormones Question 9: An isotonic solution is one which An isotonic solution has the same solute concentration (osmolarity) as the inside of a cell. This results in no net movement of water across the cell membrane, and the cell maintains its normal shape and volume. A. has an osmotic pressure that is different to red blood cells - Incorrect. B. has an osmolarity less than that of red blood cells - Incorrect (hypotonic). C. causes no net movement of water between the solution and red blood cells - Correct. D. has an osmolarity greater than that of red blood cells - Incorrect (hypertonic). The correct option is C. C. causes no net movement of water between the solution and red blood cells Question 10: One of the buffer systems in the blood is the carbonic acid/bicarbonate buffer. It helps to maintain the body's acid-base balance by destroying any excess: The carbonic acid/bicarbonate buffer system neutralizes both excess acids (hydrogen ions) and excess bases (hydroxide ions) to maintain a stable pH. A. Hydrogen ions in the blood - Neutralizes excess H\(_+\). B. acid or base in the blood - This is a comprehensive description of a buffer's function. C. Hydroxide ions formed in the blood - Neutralizes excess OH\(_-\). D. bicarbonate ions formed in the blood - Bicarbonate ions are part of the buffer, not what it destroys. The most complete and accurate answer describing what the buffer system destroys is B. B. acid or base in the blood Question 11: The primary somatosensory cortex is located in the: The primary somatosensory cortex processes sensory information and is located in the postcentral gyrus of the parietal lobe. A. Precentral gyrus - Primary motor cortex. B. Postcentral gyrus - Primary somatosensory cortex. C. Frontal pole - Part of the frontal lobe. D. Temporal cortex - Auditory processing. The correct option is B. B. Postcentral gyrus Question 12: Which of the following statements about the role of the kidneys or lungs in the maintenance of acid-base balance in the body is FALSE? Let's evaluate each statement: A. The kidneys are able to affect several buffer systems but the lungs affect only one. (True: Lungs affect carbonic acid; kidneys affect carbonic acid, phosphate, ammonia.) B. The lungs exert their influence on the carbonic acid/bicarbonate buffer system. (True: By regulating CO\(_2\).) C. Neither the lungs nor the kidneys have much influence over the protein buffer. (False: They influence overall pH, which affects all buffer systems, including protein buffers.) D. The kidneys are able to respond more rapidly than the lungs to changes in acid-base balance. (False: Lungs respond rapidly (minutes), kidneys respond slowly (hours to days).) Both C and D are false statements. However, the speed of response (D) is a fundamental and distinct difference between renal and respiratory compensation, making it unequivocally false. The correct option is D. D. The kidneys are able to respond more rapidly than the lungs to changes in acid-base balance. Question 13: Choose one answer below that completes the sentence so that it makes a true statement: Positive feedback: Positive feedback mechanisms amplify an initial stimulus, moving the system further away from the set point. Homeostasis is primarily maintained by negative feedback. A. is the way the body maintains homeostasis - This is false; negative feedback maintains homeostasis. B. is a response that opposes a stimulus - This is false; this describes negative feedback. The options C and D are not visible in the provided image. Therefore, I cannot fully answer this question. 3 done, 2 left today. You're making progress.