9: Wheat, Poaceae, The Green Revolution: Flashcards
Where did wheat originate?
In the Fertile Crescent.
What key property makes wheat valuable for baking?
Its high gluten content, which gives dough visco-elastic properties to rise and hold shape.
What are the basic steps in processing cereal grains after harvest?
Reaping → Gathering → Threshing → Winnowing → Milling.
What is gluten composed of in wheat?
Prolamin (gliadin) and glutelin (glutenin).
How does gluten contribute to baked goods?
It forms a visco-elastic matrix that traps CO₂ from yeast, making dough rise and hold shape when baked.
What’s the key difference between grains and achenes?
In grains (Poaceae), the pericarp is fused to the seed coat; in achenes (Asteraceae), it is not fused.
Name the 3 major types of wheat rust
Leaf rust – Puccinia triticina
Stem rust – Puccinia graminis
Stripe rust – Puccinia striiformis
Who was Norman Borlaug and what did he do?
He was the “architect” of the Green Revolution; he bred rust-resistant wheat in Mexico.
What is shuttle-cropping and why was it useful?
Planting two wheat crops yearly in different Mexican regions to speed up breeding and test environmental adaptability.
What parts of the grain are in whole grain flour?
Endosperm, bran, and germ.
What does refined flour contain?
Only the endosperm (bran and germ removed).
What is the Haber-Bosch process?
Industrial synthesis of ammonia for nitrogen fertilizer.
One environmental consequence of the Haber-Bosch process?
High greenhouse gas emissions during production.
What is bioaccumulation?
Buildup of substances (e.g., pesticides) in an organism over time.
What is biomagnification?
Increasing concentration of toxins at higher levels of the food chain.
What is a grain (botanically)?
A fruit in which the pericarp is fused to the seed coat (Poaceae family).
What is a floret in wheat?
A small flower within a spikelet.
What is a spikelet?
A small spike containing one or more florets in grasses.
Define visco-elastic.
Exhibiting both viscous and elastic behavior when deformed.
What is the role of the endosperm in a seed?
It nourishes the developing embryo and is the main part of refined flour.
What does a combine harvester do?
Performs reaping, threshing, and winnowing in one machine.
What is milling?
Grinding grain into flour.
What is threshing?
Separating grain from the rest of the plant.
What is winnowing?
Removing chaff from grain using airflow.
