Which of the following statements best describes homeostasis? (a) Keeping the body in a fixed and unaltered state (b) Dynamic equilibrium (c) Maintaining a near-constant internal environment (d) Altering the external environment to accommodate the body’s need Stimulation of the heat-loss center causes (a) Blood vessels in the skin to constrict (b) Breathing to become slow and shallow (c) Sweat glands to increase their output (d) All of the above. Which one of the following is the reaction of the skin of a human when the body becomes very cold? (a) The arterioles constrict, the hair stands on end and sweat production ceases (b) The arterioles constrict, the hair lies flat on the skin and sweating occurs (c) The arterioles dilate, the hair stands on end and sweat production almost ceases (d) The arterioles dilate, the hair lies flat on the skin and sweating occurs What is the result of a rise in body temperature? (a) A decrease in the production of sweat (b) An increase in blood flow to the skin (c) Narrowing of blood vessels in the skin (d) Raising of hairs on the skin Q181 On the blank spectra below, sketch and label major IR peaks with the associated functional group and give an approximate frequency (in cm-1) for: A.) The Acetylation Product B.) Sucralose The number -13 is greater than -15
The Correct Answer and Explanation is :
Homeostasis
The correct answer is:
(c) Maintaining a near-constant internal environment
Homeostasis refers to the body’s ability to maintain a stable internal environment despite external changes. This process ensures that variables such as body temperature, blood pH, and glucose levels remain within narrow, optimal ranges necessary for proper physiological function.
Stimulation of the Heat-Loss Center
The correct answer is:
(c) Sweat glands to increase their output
When the body is overheated, the hypothalamus activates the heat-loss center, triggering mechanisms like sweating to cool the body. Sweat evaporation helps reduce body temperature. Additionally, blood vessels in the skin may dilate to facilitate heat dissipation.
Reaction of the Skin When the Body Becomes Very Cold
The correct answer is:
(a) The arterioles constrict, the hair stands on end, and sweat production ceases
In response to cold, the body attempts to conserve heat by constricting blood vessels (vasoconstriction) to reduce heat loss from the skin. The hair stands on end (piloerection) as a mechanism to trap air, which serves as an insulative layer. Sweating stops as the body reduces heat loss.
Result of a Rise in Body Temperature
The correct answer is:
(b) An increase in blood flow to the skin
When body temperature rises, the hypothalamus stimulates vasodilation of blood vessels in the skin. This allows increased blood flow to the skin’s surface, which facilitates heat dissipation through radiation and sweating, helping to cool the body down.
IR Spectra Explanation (Acetylation Product and Sucralose)
For IR spectra:
- Acetylation Product: The main functional group associated with acetylation is the acetyl group (-COCH3). This group typically shows a strong carbonyl (C=O) stretch around 1725 cm⁻¹ in the IR spectrum.
- Sucralose: This compound contains multiple functional groups, such as hydroxyl (-OH) and ether (C-O-C). The -OH group typically shows a broad stretch around 3200–3550 cm⁻¹, and the ether groups typically show peaks around 1000–1300 cm⁻¹.
I will now generate the IR spectra for both the acetylation product and sucralose, with labeled functional groups and frequencies.
Here is the IR spectra illustration for both the acetylation product and sucralose, with labeled functional groups and their corresponding frequencies. The acetylation product shows the carbonyl stretch around 1725 cm⁻¹, while sucralose displays peaks for the hydroxyl group around 3200–3550 cm⁻¹ and ether groups around 1000–1300 cm⁻¹. Let me know if you need further clarification!
