Agriculture
The Agriculture CST samples broadly across plant science, animal science, natural resources, agribusiness, technology, and agricultural education/leadership. Most items are scenario-based: you are given a production or management situation and asked to apply a principle, so connect vocabulary to consequences.
Core science anchors
- Plants: photosynthesis, transpiration, soil texture (read the sand–silt–clay triangle carefully), pH effects on nutrient availability, and integrated pest management-scout, identify, and treat only above an economic threshold.
- Animals: distinguish ruminant fermentation (rumen microbes digest fiber) from monogastric digestion; know nutrient classes-water, energy, protein, minerals, vitamins-and that a ration must be balanced, not simply larger.
- Natural resources: erosion progresses from sheet to rill to gully; conservation practices such as contour strips, cover crops, and riparian buffers reduce soil and nutrient loss.
Worked example: polled genetics
In cattle, polled (P) is dominant to horned (p). A heterozygous polled bull (Pp) is mated to a horned cow (pp). The bull produces P and p gametes in equal numbers; the cow produces only p. The Punnett square gives Pp, pp, Pp, pp-so about 50% polled (heterozygous) and 50% horned calves. The reasoning: the cow cannot supply a dominant allele, so each calf's phenotype depends on which allele the bull transmits.
Agribusiness and leadership
Separate fixed costs (land, equipment) from variable costs (seed, feed, fuel); break-even yield equals total costs divided by price per unit. In agricultural education, an SAE is a supervised, work-based application of classroom learning, not a club activity.
Traps that cost marks
- Reading the soil texture triangle from the wrong axis or direction.
- Assuming a dominant phenotype guarantees all offspring show it.
- Confusing sheet, rill, and gully erosion.
- Treating organic production as pest-free rather than management by approved practices.
- Selecting the largest number in a ration or budget problem instead of balancing the limiting factor.