Nutrition Science Quiz

Grade 9 · Health · Quiz

Test your knowledge of macronutrients, micronutrients, metabolism, and evidence-based dietary principles.

Questions

1. Which process converts glucose into ATP (energy) in the presence of oxygen?

   1. Anaerobic glycolysis
   2. Aerobic cellular respiration
   3. Gluconeogenesis
   4. Beta-oxidation
   Show answer

   Answer: Aerobic cellular respiration

   Aerobic cellular respiration (glycolysis + Krebs cycle + electron transport chain) converts glucose and oxygen into ATP, water, and CO2; it produces far more ATP than anaerobic pathways.

2. A meal consisting of rice and beans is an example of:

   1. Two complete proteins combined
   2. Combining incomplete proteins to obtain all essential amino acids
   3. An unhealthy combination due to excess carbohydrates
   4. A meal lacking any significant protein
   Show answer

   Answer: Combining incomplete proteins to obtain all essential amino acids

   Rice is low in lysine but high in methionine; beans are high in lysine but low in methionine. Combining them creates a complete amino acid profile — a concept called protein complementation.

3. Which vitamin is unique in that the primary source for humans is skin synthesis from ultraviolet light exposure?

   1. Vitamin A
   2. Vitamin C
   3. Vitamin D
   4. Vitamin B12
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   Answer: Vitamin D

   When UVB radiation hits skin, 7-dehydrocholesterol is converted to pre-vitamin D3, which is then converted to active vitamin D3 (cholecalciferol). Most other vitamins must come entirely from diet.

4. The MyPlate model recommends that grains consumed should be primarily:

   1. Refined white grains for easy digestion
   2. Whole grains at least half the time
   3. Eliminated in favor of more protein
   4. Eaten only at breakfast
   Show answer

   Answer: Whole grains at least half the time

   Whole grains retain the bran and germ, providing fiber, B vitamins, and minerals. MyPlate recommends making at least half of all grains consumed whole grains.

5. Which type of fat is found in olive oil and avocados and is considered beneficial for heart health?

   1. Saturated fat
   2. Trans fat
   3. Monounsaturated fat
   4. Cholesterol
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   Answer: Monounsaturated fat

   Monounsaturated fats (one double bond in the carbon chain) lower LDL cholesterol and reduce cardiovascular risk; olive oil and avocados are rich sources.

6. Iron deficiency anemia impairs health primarily because iron is required for:

   1. Insulin production in the pancreas
   2. Synthesis of hemoglobin, which carries oxygen in red blood cells
   3. Calcium absorption in the intestine
   4. Digestion of dietary fat in the small intestine
   Show answer

   Answer: Synthesis of hemoglobin, which carries oxygen in red blood cells

   Hemoglobin is the iron-containing protein in red blood cells that binds and transports oxygen. Without adequate iron, fewer functional red blood cells are produced, leading to fatigue and impaired organ function.

7. Eating a diet high in ultra-processed foods is associated with increased risk of obesity, type 2 diabetes, and cardiovascular disease.

   Show answer

   Answer: True

   Multiple large-scale studies link ultra-processed food consumption (high sugar, refined carbs, unhealthy fats, low fiber) to metabolic syndrome, obesity, cardiovascular disease, and type 2 diabetes.

8. The calorie content per gram of fat is ______ kcal/g.

   Show answer

   Answer: 9

   Fat provides 9 kcal per gram, compared to 4 kcal/g for carbohydrates and protein. This is why fat-rich foods are calorie-dense and why fat is the body's primary long-term energy storage form.

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