Nokea
Which molecules are soluble in nonpolar solvents but are hydrophobic?
- A. Carbohydrates
- B. Lipids
- C. Proteins
- D. Nucleic acids
Correct Answer: B
Rationale: Lipids are hydrophobic molecules that are soluble in nonpolar solvents like oils but insoluble in water. They consist of fats, oils, waxes, and steroids and play essential roles in energy storage, insulation, and cell membrane structure. Carbohydrates, proteins, and nucleic acids are not typically soluble in nonpolar solvents and do not exhibit the same hydrophobic characteristics as lipids. Carbohydrates are usually hydrophilic and soluble in water, proteins have both hydrophilic and hydrophobic regions but are not generally soluble in nonpolar solvents, and nucleic acids are polar molecules that are not known for their solubility in nonpolar solvents.
You may also like to solve these questions
What do large intestines absorb?
- A. Water, sodium, and potassium ions
- B. Proteins and carbohydrates
- C. Water, vitamin K, and bile salts
- D. Vitamins A, D, E, K
Correct Answer: C
Rationale: The correct answer is C. The large intestine absorbs water, vitamin K, bile salts, sodium, and chloride ions. It helps in maintaining the body's water and electrolyte balance, and also plays a role in absorbing certain vitamins and nutrients such as vitamin K. Choices A, B, and D are incorrect because proteins, carbohydrates, vitamins A, D, E, and K are primarily absorbed in the small intestine, not the large intestine.
Which of the following areas of the body has the most sweat glands?
- A. Upper back
- B. Arms
- C. Feet
- D. Palms
Correct Answer: D
Rationale: The correct answer is D: Palms. The palms of the hands have the highest concentration of sweat glands compared to other areas of the body. This is why sweating is commonly noticed on the palms during times of stress or physical exertion. Choices A, B, and C are incorrect. While these areas do have sweat glands, they are not as densely distributed as in the palms. The upper back, arms, and feet do contribute to overall body sweat, but the palms have a significantly higher density of sweat glands, making them the area with the most sweat glands.
What hormones are produced in the ovaries, and what are their functions?
- A. Insulin: regulates blood sugar levels
- B. Progesterone: stimulates uterine lining growth
- C. Adrenaline: increases heart rate
- D. Cortisol: regulates stress response
Correct Answer: B
Rationale: The correct answer is B. Progesterone, produced in the ovaries, stimulates uterine lining growth and plays a crucial role in regulating the menstrual cycle. Insulin is produced in the pancreas to regulate blood sugar levels, not in the ovaries. Adrenaline is produced by the adrenal glands and increases heart rate in response to stress or danger, not in the ovaries. Cortisol, also produced by the adrenal glands, helps regulate the body's response to stress, not in the ovaries.
Which of the following glands helps regulate calcium levels?
- A. Osteotoid gland
- B. Pineal gland
- C. Parathyroid glands
- D. Thymus gland
Correct Answer: C
Rationale: The correct answer is C: Parathyroid glands. The parathyroid glands are responsible for regulating calcium levels in the body. They produce parathyroid hormone (PTH), which helps control calcium levels in the blood by acting on the bones, kidneys, and intestines. The other options, such as the osteotoid gland, pineal gland, and thymus gland, do not play a significant role in calcium regulation. The osteotoid gland is a fictitious term, the pineal gland is involved in regulating sleep-wake cycles and producing melatonin, and the thymus gland is part of the immune system and plays a role in T-cell maturation.
What are the phases of bacterial growth and infection?
- A. Lag, exponential, stationary, death
- B. Exponential, stationary, lag, death
- C. Stationary, exponential, lag, death
- D. Lag, stationary, exponential, death
Correct Answer: A
Rationale: The correct answer is A: Lag, exponential, stationary, death. The phases of bacterial growth start with the lag phase where bacteria acclimate to their environment, followed by the exponential phase characterized by rapid growth. This is then followed by the stationary phase where growth slows as resources deplete, and finally, the death phase where the population declines. Choice B is incorrect as it has the order of phases mixed up. Choice C is incorrect as it also has the order of phases mixed up. Choice D is incorrect as it has the stationary phase occurring before the exponential phase, which is inaccurate.