What area D asks for. UC’s area D is laboratory science: substantial hands-on work in which students plan investigations, collect and analyze their own data and argue from it, at the depth of a college-preparatory course. Biology B meets it with hands-on work in every unit: duckweed population growth, heat from germinating seeds, schoolyard quadrats and bean mark-recapture in Unit 1; brine shrimp hatching and post-fire erosion prototypes in Unit 2; a camouflage predation investigation in Unit 3; and a pill bug choice chamber and a bead model of genetic drift in Unit 4. Simulations (PhET Natural Selection and the NetLogo Web models) support these labs; they never replace them for the class.

Protect the lab share. The course commits to at least 20% of class time in hands-on laboratory work. Biology B’s labs run over days (duckweed for three weeks, seeds for 48 hours, brine shrimp for two days), so plan the set-up days carefully and do not let them slip. If a lab cannot run, reschedule it; the alternatives are for individual students, not for the class.

The performance expectations. Biology B cites HS-LS2-1, 2-2, 2-4, 2-6, 2-7 and 2-8 (populations, energy, stability, human impact, group behavior), all of HS-LS4 (evidence for evolution, natural selection, adaptation, speciation and extinction, and simulating solutions for biodiversity), and HS-ETS1-1 to HS-ETS1-4, which are concentrated in Unit 2’s design cycle. Biology A covers HS-LS1, HS-LS3, HS-LS2-3 and HS-LS2-5, and Biology B revisits HS-LS2-3 in Unit 1.

Engineering is part of the science. Unit 2 is a full design cycle: define criteria and constraints, break the problem into sub-problems, compare solutions in a weighted decision matrix, test with a prototype or simulation, and refine. Keep all five steps; a brief that skips testing is an essay, not a design.

Math is part of the science. Students fit exponential and logistic models, estimate populations by mark-recapture, compute Simpson’s index, apply the ten percent rule, weight decision matrices, compute proportions under selection, and use chi-square and Hardy-Weinberg. Scaffold the arithmetic; do not remove it.