351. A person with a deficiency in vitamin K would most likely experience:
A) Night blindness
B) Excessive bleeding
C) Muscle weakness
D) Poor wound healing
Correct Answer: B) Excessive bleeding
Explanation: Vitamin K is essential for the synthesis of clotting factors in the blood. A deficiency impairs the blood’s ability to clot, leading to excessive bleeding or easy bruising.
352. If a plant is grown in soil lacking magnesium, which symptom is most likely to appear?
A) Wilting
B) Yellowing of older leaves
C) Stunted root growth
D) Increased flower production
Correct Answer: B) Yellowing of older leaves
Explanation: Magnesium is a central component of chlorophyll. Its deficiency causes chlorosis (yellowing), starting in older leaves, as magnesium is mobile within the plant.
353. What is the key difference between mitosis and meiosis?
A) Mitosis produces genetically identical cells; meiosis produces genetically diverse cells
B) Mitosis occurs in gametes; meiosis occurs in somatic cells
C) Mitosis reduces chromosome number; meiosis maintains chromosome number
D) Mitosis occurs only in plants; meiosis occurs only in animals
Correct Answer: A) Mitosis produces genetically identical cells; meiosis produces genetically diverse cells
Explanation: Mitosis results in two genetically identical diploid cells, while meiosis produces four genetically diverse haploid gametes due to crossing over and independent assortment.
354. What would happen if the glomerulus in the kidney is damaged?
A) Increased urine output
B) Decreased filtration of blood
C) Increased reabsorption of water
D) Decreased secretion of hormones
Correct Answer: B) Decreased filtration of blood
Explanation: The glomerulus is the site of blood filtration in the nephron. Damage would impair its ability to filter blood, leading to decreased filtration efficiency.
355. A patient with persistent high blood glucose levels is most likely suffering from a malfunction in which organ?
A) Liver
B) Pancreas
C) Spleen
D) Kidney
Correct Answer: B) Pancreas
Explanation: The pancreas produces insulin, which regulates blood glucose. Malfunction (as in diabetes) leads to persistently high blood sugar.
356. A mutation in the gene encoding RNA polymerase would most directly affect which process?
A) DNA replication
B) Transcription
C) Translation
D) Protein folding
Correct Answer: B) Transcription
Explanation: RNA polymerase is the enzyme responsible for synthesizing RNA from DNA during transcription. A mutation would impair this process.
357. A plant exposed to a high concentration of auxin on one side will most likely:
A) Grow taller
B) Bend toward the light
C) Bend away from the auxin source
D) Wilt
Correct Answer: C) Bend away from the auxin source
Explanation: Auxin promotes cell elongation. When applied asymmetrically, it causes uneven growth, making the plant bend away from the side with more auxin.
358. Which of the following best distinguishes between arteries and veins?
A) Arteries carry oxygenated blood; veins carry deoxygenated blood
B) Arteries have valves; veins do not
C) Arteries always carry blood toward the heart; veins always carry blood away from the heart
D) Arteries have thinner walls than veins
Correct Answer: A) Arteries carry oxygenated blood; veins carry deoxygenated blood
Explanation: Arteries generally carry oxygenated blood away from the heart (except pulmonary artery), while veins carry deoxygenated blood toward the heart (except pulmonary vein).
359. What would be the immediate effect if a person’s blood pH drops below 7.35?
A) Increased breathing rate
B) Decreased heart rate
C) Increased insulin secretion
D) Decreased urine output
Correct Answer: A) Increased breathing rate
Explanation: A drop in blood pH (acidosis) triggers the body to increase breathing to expel more carbon dioxide, which helps raise blood pH back to normal.
360. A patient with frequent respiratory infections and difficulty breathing may have a malfunction in which organ?
A) Heart
B) Lungs
C) Liver
D) Stomach
Correct Answer: B) Lungs
Explanation: The lungs are responsible for gas exchange and clearing pathogens from the airways. Malfunction can lead to respiratory infections and breathing difficulties.
361. A person with a damaged liver would most likely have trouble with:
A) Digestion of carbohydrates
B) Detoxification and bile production
C) Absorption of nutrients
D) Production of insulin
Correct Answer: B) Detoxification and bile production
Explanation: The liver is responsible for detoxifying harmful substances and producing bile, which aids in fat digestion. Damage would impair these functions.
362. If a plant’s xylem is blocked, which of the following would occur?
A) Reduced photosynthesis
B) Reduced water transport
C) Increased sugar transport
D) Increased flower production
Correct Answer: B) Reduced water transport
Explanation: Xylem transports water and minerals from roots to shoots. Blockage would reduce water transport, affecting the plant’s hydration and nutrient supply.
363. How do prokaryotic and eukaryotic cells differ in terms of genetic material?
A) Prokaryotes have DNA; eukaryotes have RNA
B) Prokaryotes lack a nucleus; eukaryotes have a nucleus
C) Prokaryotes have more chromosomes than eukaryotes
D) Prokaryotes have linear DNA; eukaryotes have circular DNA
Correct Answer: B) Prokaryotes lack a nucleus; eukaryotes have a nucleus
Explanation: Prokaryotic cells lack a true nucleus and membrane-bound organelles, while eukaryotic cells have both, including a nucleus that houses the genetic material.
364. What would happen if a cell is placed in a hypertonic solution?
A) The cell will swell and burst
B) The cell will shrink
C) The cell will remain unchanged
D) The cell will divide
Correct Answer: B) The cell will shrink
Explanation: In a hypertonic solution, water moves out of the cell, causing it to shrink (plasmolysis in plant cells, crenation in animal cells).
365. A patient with excessive thirst, frequent urination, and high blood sugar is most likely suffering from:
A) Diabetes
B) Anemia
C) Hypertension
D) Jaundice
Correct Answer: A) Diabetes
Explanation: These symptoms are classic signs of diabetes mellitus, a condition characterized by high blood sugar due to insufficient insulin or insulin resistance.
366. A mutation in the gene encoding hemoglobin would most likely affect:
A) Oxygen transport
B) Blood clotting
C) Immune defense
D) Digestion
Correct Answer: A) Oxygen transport
Explanation: Hemoglobin is responsible for binding and transporting oxygen in red blood cells. A mutation would impair this function.
367. If a plant’s stomata are closed during the day, what is the most likely consequence?
A) Increased photosynthesis
B) Decreased transpiration
C) Increased water uptake
D) Enhanced root growth
Correct Answer: B) Decreased transpiration
Explanation: Stomata are pores that allow water vapor to escape. If closed, transpiration (water loss) decreases, but photosynthesis may also be limited due to reduced CO₂ intake.
368. What is the main difference between facilitated diffusion and active transport?
A) Active transport requires energy; passive transport does not
B) Active transport moves substances down their concentration gradient; passive transport does not
C) Active transport is only found in plants; passive transport is only found in animals
D) Facilitated diffusion does not require energy; active transport does
Correct Answer: D) Facilitated diffusion does not require energy; active transport does
Explanation: Facilitated diffusion moves substances down their concentration gradient without energy, while active transport moves substances against their gradient and requires energy (ATP).
369. What would happen if the thyroid gland is overactive?
A) Weight gain
B) Weight loss
C) Low heart rate
D) Cold intolerance
Correct Answer: B) Weight loss
Explanation: An overactive thyroid (hyperthyroidism) increases metabolic rate, often leading to weight loss despite increased appetite.
370. A patient with frequent infections and easy bruising may have a problem with which organ?
A) Liver
B) Spleen
C) Pancreas
D) Stomach
Correct Answer: B) Spleen
Explanation: The spleen filters blood and plays a key role in immune defense. Malfunction can lead to increased susceptibility to infections and bleeding.
371. A person with a deficiency in vitamin C would most likely experience:
A) Night blindness
B) Scurvy
C) Rickets
D) Beriberi
Correct Answer: B) Scurvy
Explanation: Vitamin C is essential for collagen synthesis. Deficiency leads to scurvy, characterized by bleeding gums, poor wound healing, and bruising.
372. If a plant is exposed to a high concentration of ethylene gas, what is the most likely outcome?
A) Increased root growth
B) Accelerated fruit ripening
C) Enhanced flower production
D) Increased leaf size
Correct Answer: B) Accelerated fruit ripening
Explanation: Ethylene is a plant hormone that promotes fruit ripening and leaf abscission. Exposure to high ethylene concentrations accelerates these processes.
373. What is the main difference between DNA and RNA?
A) DNA is double-stranded; RNA is single-stranded
B) DNA contains uracil; RNA contains thymine
C) DNA is found only in the nucleus; RNA is found only in the cytoplasm
D) DNA is involved in protein synthesis; RNA is involved in energy production
Correct Answer: A) DNA is double-stranded; RNA is single-stranded
Explanation: DNA is typically double-stranded, while RNA is single-stranded. DNA contains thymine; RNA contains uracil.
374. What would happen if a cell’s mitochondria are non-functional?
A) Increased protein synthesis
B) Decreased ATP production
C) Increased lipid synthesis
D) Enhanced DNA replication
Correct Answer: B) Decreased ATP production
Explanation: Mitochondria are the primary sites of ATP production through cellular respiration. Non-functional mitochondria would reduce ATP synthesis.
375. A patient with frequent bone fractures and muscle weakness may be deficient in which vitamin?
A) Vitamin A
B) Vitamin D
C) Vitamin E
D) Vitamin K
Correct Answer: B) Vitamin D
Explanation: Vitamin D is essential for calcium absorption and bone health. Deficiency leads to weakened bones (osteoporosis or rickets) and muscle weakness.
376. A person with a damaged medulla oblongata would most likely have trouble with:
A) Memory
B) Breathing and heart rate
C) Vision
D) Digestion
Correct Answer: B) Breathing and heart rate
Explanation: The medulla oblongata controls vital involuntary functions such as breathing, heart rate, and blood pressure. Damage can be life-threatening.
377. If a plant is grown in a nitrogen-deficient environment, what symptom is most likely to appear?
A) Yellowing of older leaves
B) Yellowing of young leaves
C) Stunted root growth
D) Excessive flowering
Correct Answer: B) Yellowing of young leaves
Explanation: Nitrogen is essential for protein synthesis and chlorophyll production. Deficiency in young leaves (where nitrogen is needed most) causes yellowing, as nitrogen is less mobile than other nutrients.
378. What is the main difference between aerobic and anaerobic respiration?
A) Aerobic respiration produces more ATP; anaerobic respiration produces less ATP
B) Aerobic respiration occurs in the cytoplasm; anaerobic respiration occurs in mitochondria
C) Aerobic respiration does not require oxygen; anaerobic respiration does
D) Aerobic respiration is only found in plants; anaerobic respiration is only found in animals
Correct Answer: A) Aerobic respiration produces more ATP; anaerobic respiration produces less ATP
Explanation: Aerobic respiration uses oxygen and produces a large amount of ATP (up to 38 per glucose), while anaerobic respiration (fermentation) produces much less ATP (2 per glucose) and does not require oxygen.
379. What would happen if a cell is placed in a hypotonic solution?
A) The cell will shrink
B) The cell will swell
C) The cell will remain unchanged
D) The cell will divide
Correct Answer: B) The cell will swell
Explanation: In a hypotonic solution, water moves into the cell, causing it to swell. In animal cells, this can lead to bursting (lysis); in plant cells, the cell wall prevents bursting.
380. A patient with persistent fatigue, pale skin, and shortness of breath may be suffering from:
A) Diabetes
B) Anemia
C) Hypertension
D) Jaundice
Correct Answer: B) Anemia
Explanation: These symptoms are characteristic of anemia, a condition in which there is a deficiency of red blood cells or hemoglobin, reducing oxygen delivery to tissues.
381. A person with a deficiency in vitamin A would most likely experience:
A) Night blindness
B) Scurvy
C) Rickets
D) Beriberi
Correct Answer: A) Night blindness
Explanation: Vitamin A is essential for the synthesis of visual pigments in the retina. Deficiency impairs night vision and can lead to night blindness.
382. If a plant is exposed to red light, which process is most likely to be affected?
A) Photosynthesis
B) Respiration
C) Transpiration
D) Germination
Correct Answer: A) Photosynthesis
Explanation: Photosynthesis is driven by light, with chlorophyll absorbing red and blue wavelengths most efficiently. Red light exposure would primarily affect photosynthesis.
383. What is the main difference between active and passive transport?
A) Active transport requires energy; passive transport does not
B) Active transport moves substances down their concentration gradient; passive transport does not
C) Active transport is only found in plants; passive transport is only found in animals
D) Active transport does not use proteins; passive transport does
Correct Answer: A) Active transport requires energy; passive transport does not
Explanation: Active transport moves substances against their concentration gradient and requires energy (ATP), while passive transport moves substances down their gradient without energy.
384. What would happen if the myelin sheath around a neuron is damaged?
A) The neuron would produce more neurotransmitters
B) Nerve impulse transmission would slow down
C) The neuron would divide more rapidly
D) The neuron would become less sensitive to stimuli
Correct Answer: B) Nerve impulse transmission would slow down
Explanation: The myelin sheath insulates axons and speeds up nerve impulse transmission. Damage would slow down signal conduction, as seen in diseases like multiple sclerosis.
385. A patient with persistent high blood pressure and swelling in the legs may have a problem with which organ?
A) Heart
B) Kidney
C) Liver
D) Lungs
Correct Answer: B) Kidney
Explanation: The kidneys regulate blood pressure and fluid balance. Malfunction can lead to high blood pressure and edema (swelling) due to fluid retention.
386. A person with a damaged cerebellum would most likely have trouble with:
A) Memory
B) Balance and coordination
C) Vision
D) Digestion
Correct Answer: B) Balance and coordination
Explanation: The cerebellum is responsible for coordinating voluntary movements, maintaining posture, and ensuring smooth, balanced actions.
387. If a plant is grown in a waterlogged environment, what is the most likely consequence?
A) Increased photosynthesis
B) Oxygen deficiency in roots
C) Increased transpiration
D) Enhanced root growth
Correct Answer: B) Oxygen deficiency in roots
Explanation: Waterlogged soil lacks oxygen, leading to root hypoxia. This impairs root respiration and nutrient uptake, potentially causing root death and stunted growth.
388. What is the main difference between innate and adaptive immunity?
A) Innate immunity is specific; adaptive immunity is non-specific
B) Innate immunity is present at birth; adaptive immunity develops after exposure
C) Innate immunity uses antibodies; adaptive immunity does not
D) Innate immunity is only found in plants; adaptive immunity is only found in animals
Correct Answer: B) Innate immunity is present at birth; adaptive immunity develops after exposure
Explanation: Innate immunity is the body’s first line of defense and is present from birth. Adaptive immunity develops after exposure to specific pathogens and provides long-lasting protection.
389. What would happen if the adrenal glands are overactive?
A) Low blood pressure
B) High blood pressure and rapid heart rate
C) Decreased blood sugar
D) Increased digestion
Correct Answer: B) High blood pressure and rapid heart rate
Explanation: Overactive adrenal glands produce excess adrenaline and cortisol, leading to increased heart rate, high blood pressure, and heightened stress responses.
390. A patient with persistent diarrhea, weight loss, and abdominal pain may have a problem with which organ?
A) Heart
B) Kidney
C) Small intestine
D) Lungs
Correct Answer: C) Small intestine
Explanation: The small intestine is the main site of nutrient absorption. Conditions like celiac disease or infections can impair absorption, causing diarrhea, weight loss, and abdominal pain.
391. A person with a deficiency in vitamin B12 would most likely experience:
A) Night blindness
B) Anemia and nerve damage
C) Scurvy
D) Rickets
Correct Answer: B) Anemia and nerve damage
Explanation: Vitamin B12 is essential for red blood cell formation and nerve function. Deficiency leads to megaloblastic anemia and neurological symptoms.
392. If a plant is exposed to blue light, which process is most likely to be affected?
A) Photosynthesis
B) Respiration
C) Transpiration
D) Germination
Correct Answer: A) Photosynthesis
Explanation: Chlorophyll absorbs blue light efficiently, making photosynthesis the process most affected by blue light exposure.
393. Which of the following best distinguishes between hormones and neurotransmitters?
A) Hormones are only produced by plants; neurotransmitters are only produced by animals
B) Hormones act over long distances; neurotransmitters act over short distances
C) Hormones are always proteins; neurotransmitters are always lipids
D) Hormones are only found in the blood; neurotransmitters are only found in the brain
Correct Answer: B) Hormones act over long distances; neurotransmitters act over short distances
Explanation: Hormones are chemical messengers transported by the blood to distant target organs, while neurotransmitters transmit signals across synapses between neurons.
394. What would happen if the parathyroid glands are removed?
A) Blood calcium levels would rise
B) Blood calcium levels would fall
C) Blood sugar levels would rise
D) Blood sugar levels would fall
Correct Answer: B) Blood calcium levels would fall
Explanation: The parathyroid glands produce parathyroid hormone, which raises blood calcium levels. Removal would lead to hypocalcemia (low blood calcium).
395. A patient with persistent coughing, wheezing, and shortness of breath may have a problem with which organ?
A) Heart
B) Kidney
C) Lungs
D) Liver
Correct Answer: C) Lungs
Explanation: These symptoms are typical of respiratory conditions such as asthma or chronic obstructive pulmonary disease (COPD), which affect the lungs.
396. A person with a damaged hypothalamus would most likely have trouble with:
A) Memory
B) Regulation of body temperature and hunger
C) Vision
D) Digestion
Correct Answer: B) Regulation of body temperature and hunger
Explanation: The hypothalamus regulates homeostasis, including body temperature, hunger, thirst, and sleep-wake cycles.
397. If a plant is grown in a potassium-deficient environment, what symptom is most likely to appear?
A) Yellowing of older leaves
B) Yellowing of young leaves
C) Weak stems and leaf edges
D) Excessive flowering
Correct Answer: C) Weak stems and leaf edges
Explanation: Potassium is essential for enzyme activation, water regulation, and structural integrity. Deficiency leads to weak stems, leaf edge necrosis, and poor growth.
398. Which of the following best distinguishes between autotrophs and heterotrophs?
A) Autotrophs produce their own food; heterotrophs consume other organisms
B) Autotrophs are only found in water; heterotrophs are only found on land
C) Autotrophs are always multicellular; heterotrophs are always unicellular
D) Autotrophs do not need energy; heterotrophs do
Correct Answer: A) Autotrophs produce their own food; heterotrophs consume other organisms
Explanation: Autotrophs (like plants) produce their own food via photosynthesis, while heterotrophs (like animals) obtain energy by consuming other organisms.
399. What would happen if the pituitary gland is damaged?
A) Blood sugar regulation would be impaired
B) Growth and hormone regulation would be affected
C) Digestion would be impaired
D) Blood pressure would increase
Correct Answer: B) Growth and hormone regulation would be affected
Explanation: The pituitary gland is the master gland that regulates growth and the activity of other endocrine glands. Damage would disrupt hormone balance and growth.
400. A patient with persistent swelling in the legs and fatigue may have a problem with which organ?
A) Heart
B) Kidney
C) Liver
D) Lungs
Correct Answer: A) Heart
Explanation: Heart failure can lead to fluid retention (edema) in the legs and fatigue due to reduced blood circulation and oxygen delivery to tissues.