Domain: Natural Science — Chemistry
Target concept: Yeast Catalase Foam Height as a Function of Time and Temperature

Video generation prompt: Three transparent containers containing equal volumes of yeast suspension were placed in cold water, ambient air, and a warm water bath, respectively. Equal amounts of hydrogen peroxide were added to each container, and the change in foam height was observed over time.

Evaluation guide:
(i) Target concept: Enzyme reaction rate dependence on temperature, mediated by catalase in yeast breaking down H₂O₂ into O₂ and H₂O, where O₂ gas forms foam in aqueous suspension.
Minimum mechanism: Catalase must be biologically active (yeast viable), H₂O₂ must be present and reactive, temperature gradient must differentially modulate molecular collision frequency and enzyme conformational stability: cold slows, warm accelerates, ambient is baseline.
(ii)Storyline: Frame 1–2: Three transparent containers side-by-side, each filled with homogeneous yeast suspension (tan/cloudy liquid), no foam. Frame 3–4: Simultaneous addition of clear liquid (H₂O₂) to all three containers, with visible pouring motion into each. Frame 5–10: Foam emerges and grows vertically within each container; foam height diverges progressively: left (cold) shortest, center (ambient) medium, right (warm) tallest; foam remains confined, white, bubbly, and translucent; camera viewpoint static, front-facing, full-container framing; lighting even, no occlusion.

Manual:
Experimental Procedure
1. Place three identical transparent containers side-by-side.
2. Fill each with equal volume of yeast suspension.
3. Position left container in cold water, center in ambient air, right in warm water bath.
4. Simultaneously add equal amounts of hydrogen peroxide to all three.
5. Observe foam height change over time.
Observation of Experimental Phenomena
Foam rises in all containers after addition; foam height is lowest in cold, intermediate in ambient, highest in warm — difference visually sustained over time.
Summary of Experimental Principles
Yeast catalase enzyme activity increases with temperature (up to optimum); higher activity → faster H₂O₂ decomposition → more O₂ gas → greater foam volume/height.

Prompt Grounding rubric:
level_1: No transparent containers visible; or fewer than three containers; or containers not side-by-side in same scene; or no yeast suspension visible in any container; or no hydrogen peroxide addition action shown; or foam height change not depicted at all.
level_2: Exactly three transparent containers present and side-by-side, but at least one container lacks visible yeast suspension; OR hydrogen peroxide addition is shown but not to all three containers; OR foam appears in only one container with no temporal progression shown.
level_3: Three transparent containers of equal size stand side by side, each holding a visible tan, cloudy yeast suspension; hydrogen peroxide is poured into all three containers; rising foam is visibly depicted over time in each of the three containers.
level_4: Everything required at level 3 is present, and additionally, the three containers carry a distinguishing thermal cue (e.g., ice cubes or frost against the left container's exterior, visible steam or mist around the right container, no such cue at the center container), and the resulting foam heights are visibly different from one another (at least one container's foam column is clearly taller than another's).
level_5: Everything required at level 4 is present, and additionally, the thermal setup is unambiguous and internally consistent (the cold container shows ice or condensation beading on the glass, the warm container shows steam wisps or gentle ripples consistent with a heated bath, and the ambient container shows neither), the foam heights follow a strict left < center < right ordering (cold shortest, warm tallest) with no ties or reversals, and the three foam columns stay visually separated by their container walls with no foam bridging, spilling over, or merging between containers.

Scientific and Causal Correctness rubric:
level_1: Foam appears before the hydrogen peroxide is poured in, or foam rises identically in all three containers regardless of their thermal condition, or foam in the warm container shrinks while the cold container's foam grows, or the foam is a color other than white (e.g., yellow or brown) instead of a pale, translucent bubbly foam.
level_2: Foam forms in only one of the three containers after the hydrogen peroxide is added, or foam appears simultaneously with identical height in all three containers, or the foam collapses immediately in every container with no sustained height difference ever visible.
level_3: Foam rises in all three containers after the hydrogen peroxide is added; the foam is a pale, translucent, bubbly texture; at some point after addition, the warm container's foam column is visibly taller than the cold container's.
level_4: Everything required at level 3 holds, and additionally, the ambient container's foam height sits visibly between the cold and warm containers' foam heights at every point after addition, and the warm container's foam rises noticeably faster at first than the cold container's.
level_5: Everything required at level 4 holds, and additionally, the foam-height order cold ≤ ambient ≤ warm holds at every frame shown after the hydrogen peroxide is added with no frame reversing that order, no foam spills from one container into another, and the foam retains a bubbly aqueous texture throughout (never turning into smoke, vapor, or a solid precipitate).

Spatiotemporal Consistency rubric:
level_1: One of the three containers vanishes or jumps to a new position between frames, the scene's lighting suddenly changes so a container becomes hard to see, a container's wall disappears then reappears, the foam column appears or disappears between two frames with no visible rise in between, or the camera suddenly cuts from a close view of one container to a wide shot of all three with no transition.
level_2: The camera stays fixed but one or more containers slide sideways or rotate between frames, a foam column jumps from empty to mostly full within a single frame instead of rising gradually, the lighting flickers so a container's foam becomes hard to see for a moment, or a container's rim looks bent or stretched in more than one frame.
level_3: The camera holds a fixed side-by-side view of all three containers throughout, the containers stay in place and upright, each foam column rises gradually without any single-frame jump larger than its visible growth pace, the lighting stays even across all three containers, and no container or foam column shows a visible break or gap.
level_4: Everything required at level 3 holds, and additionally, foam begins rising in all three containers within a couple of frames of each other (not staggered by a long delay), each foam surface stays roughly level rather than tilting or slumping to one side, and the tabletop and background behind the containers stay the same throughout with no shift in perspective.
level_5: Everything required at level 4 holds, and additionally, the foam's rise looks smooth and continuous with no visible stutter, strobing, or repeated frames; the container rims stay crisp rather than blurring in and out of focus; no stray shadow or light glare appears or disappears between the containers; and the camera shows no visible shake or wobble throughout the sequence.