Mix of multiple choice, true/false, and fill-in-the-blank
Instant feedback after each question
Unlimited attempts for practice
Estimated time: 20–25 minutes
QUESTION 1
Which carbohydrate is the main transport form in plants?
✅ Correct! Sucrose (glucose + fructose) is the main transport sugar in plants. It moves through phloem from source tissues (leaves) to sink tissues (roots, fruits, seeds). Glucose is used locally, and starch is for storage.
QUESTION 2
What are the two components of starch?
✅ Correct! Starch consists of amylose (linear chain) and amylopectin (branched chain). The ratio affects cooking properties—waxy potatoes have more amylopectin, floury potatoes have more amylose.
QUESTION 3
What does Brix measure in fruits and vegetables?
✅ Correct! Brix measures soluble solids, primarily sugars. One degree Brix = 1 gram of sucrose in 100 grams of solution. It's widely used to assess fruit quality and harvest timing.
QUESTION 4
Which of the following is a climacteric fruit (continues to ripen after harvest)?
✅ Correct! Bananas are climacteric fruits—they continue to ripen after harvest, with starch converting to sugars. Grapes, oranges, and strawberries are non-climacteric and only ripen on the plant.
QUESTION 5
What structural feature makes unsaturated fatty acids liquid at room temperature?
✅ Correct! Double bonds in unsaturated fatty acids create kinks in the hydrocarbon chain, preventing tight packing. This lowers the melting point, making them liquid at room temperature.
QUESTION 6
Why are phospholipids described as "amphipathic"?
✅ Correct! "Amphipathic" means having both hydrophilic (water-loving) and hydrophobic (water-fearing) regions. The phosphate head is hydrophilic; the fatty acid tails are hydrophobic—allowing phospholipids to form bilayers.
QUESTION 7
What is the primary function of the waxy cuticle on leaves and fruits?
✅ Correct! The waxy cuticle's primary function is to reduce water loss (transpiration). It also provides protection against pathogens and UV radiation.
QUESTION 8
Heavier oils applied to fruit trees in winter to control overwintering pests are called ________ oils.
✅ Correct! Dormant oils are applied during the dormant season (winter/early spring) to control overwintering insect eggs, scales, and aphids. Summer oils are lighter and used during the growing season.
QUESTION 9
True or False: During cold acclimation, plants increase saturated fatty acids in their membranes.
✅ Correct! It's False. During cold acclimation, plants increase unsaturated fatty acids in their membranes. The double bonds create kinks that maintain membrane fluidity at low temperatures. Saturated fats would make membranes too rigid.
QUESTION 10
Which natural wax, derived from Brazilian palm leaves, is commonly used to coat apples and citrus?
✅ Correct! Carnauba wax comes from the leaves of the Brazilian carnauba palm. It's food-grade, provides high gloss, and is commonly used on fresh produce.
QUESTION 11
Which of the following is a common use for anti-transpirants in horticulture?
✅ Correct! Anti-transpirants reduce water loss from leaves, making them valuable for reducing transplant shock, protecting plants during drought, and extending the life of cut Christmas trees.
QUESTION 12
What is the local name for niger seed (Guizotia abyssinica), an important oilseed crop in Ethiopia?
✅ Correct! Niger seed is called "nug" (or noog) in Ethiopia. It's an important oilseed crop, with oil used for cooking and traditional dishes. Ethiopia is one of the world's largest producers.
📊 Section 1.2 Complete!
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Great job! Review the explanations for any questions you missed.
📌 Section 1.2 Complete!
You have completed all units in Section 1.2: Carbohydrates and Lipids. You should now be able to:
Distinguish between mono-, di-, and polysaccharides
Explain how carbohydrate composition affects crop quality (Brix, starch types)
Describe the structure and function of lipids in plants
Apply lipid biochemistry to pest management, post-harvest coatings, and stress tolerance
Understand the importance of oilseed crops in Ethiopian horticulture
👉 Next: In Section 1.3, we'll explore proteins and enzymes—the catalysts of plant growth.
Plant Biochemistry for Horticulture · HORT 202 · Dilla University · Last updated March 2026