Domain: Natural Science — Chemistry
Target concept: The production of carbon dioxide bubbles increases after glucose is added to water.

Video generation prompt: Two transparent glass containers, each containing water and active yeast, are placed side by side; glucose was added only to the right container, while the left one remained unchanged.

Evaluation guide:
(i) Target concept: Glucose-dependent enhancement of CO₂ production by active yeast in aqueous suspension.
Minimum mechanism: Yeast must be viable and metabolically active; glucose must be bioavailable (dissolved or dissolving); CO₂ must form as discrete gaseous bubbles nucleating at yeast surfaces and rising due to buoyancy; absence of glucose must result in measurably lower bubble generation rate.
(ii)Storyline: Frame 0–2: Two identical transparent containers filled with water and active yeast, side-by-side, stable, yeast settling. Frame 3–4: Glucose added exclusively to right container. Visible entry into liquid, local turbidity. Frame 5–10: Progressive increase in bubble count, size, and rise frequency in right container; left container maintains baseline bubbling. Perspective: Fixed frontal, eye-level, centered view capturing both containers fully; no occlusion; lighting enables clear discrimination of bubbles against water and container walls.

Manual:
Experimental Procedure
1. Place two identical transparent glass containers side-by-side on a flat surface.
2. Fill both containers with equal volumes of water.
3. Add identical amounts of active yeast to both containers.
4. Wait 2 seconds for yeast to settle.
5. Add glucose only to the right container.
Observation of Experimental Phenomena
Bubbles form in both containers initially (from yeast respiration), but bubble production increases visibly and continuously in the right container after glucose addition; the left container shows no increase in bubbling.
Summary of Experimental Principles
Active yeast metabolizes glucose via cellular respiration, producing carbon dioxide gas — observed as rising bubbles. Without added glucose, yeast relies on endogenous reserves, yielding lower CO₂ output.

Prompt Grounding rubric:
level_1: No two transparent containers holding water and yeast are shown; the containers are not placed beside each other; or glucose is never added, or it's added to the wrong container, or to both, or before either container is set up.
level_2: Two transparent containers sit beside each other, but one is missing water or yeast; or glucose goes into a container but a viewer cannot tell which one is the 'right' container (camera angle flips, no stable framing, mirrored shot); or the glucose-adding action is shown without clearly landing in one specific container.
level_3: Both containers are visible side by side, each clearly holding water with settled yeast; glucose is added only to the container that stays on the right throughout the shot, while the container on the left is never touched, matching the prompt's setup exactly.
level_4: Everything required for score 3 holds, and in addition the glucose is added only after both containers have already been shown standing still and fully in frame (never pre-added before the containers appear), and the camera framing keeps left and right unambiguous the whole time (fixed shot, no mirrored cut, no viewpoint swap).
level_5: Everything required for score 4 holds, and in addition the glucose is a visibly identifiable solid or solution (e.g., white granules or a clear pour) that enters only the right container's liquid (with no spill, splash, or visible residue reaching the left container), and neither container is ever blocked from view, duplicated, or replaced by another object.

Scientific and Causal Correctness rubric:
level_1: Neither container shows bubbles at all; or bubbles form the same way in both containers; or bubbles show up before the glucose is added; or bubbles only ever appear in the left (untreated) container; or the two containers look identical for the whole clip with no bubbling difference between them.
level_2: Bubbling shows up in only one container, but it's the left one instead of the right; or both containers start bubbling at the same moment with no lag after the glucose goes in; or bubbles appear before the glucose touches the water; or the right container's bubbling stays flat and never picks up after glucose is added.
level_3: Both containers show some baseline bubbling, but after the glucose enters the right container its bubble count and rate visibly climb above the left container's, and this gap is visible across several frames, not just a single instant.
level_4: Building on the 3-point bar, the rise in the right container's bubbling keeps building rather than firing once and stopping, it never drops back down or stalls partway through the clip, and the left container keeps its same low, steady bubbling with no sudden burst or dead patch of its own.
level_5: Building on the 4-point bar, the bubbles themselves look like real fermentation gas (round, separate from each other, drifting up from the settled yeast at the bottom rather than clinging to the glass walls or forming right at the surface), and there's no soda-like fizzing, sudsy foam, or persistent head of froth on either container.

Spatiotemporal Consistency rubric:
level_1: Severe version: containers jump to a new spot or angle between frames; the yeast or water blink out and back; the room lighting cuts abruptly from bright to dark or a shadow snaps to a new side with no visible cause; a container's glass looks solid one moment and see-through the next; the hand adding glucose appears to pass straight through the glass wall.
level_2: A clear but lesser break: a container's rim or base warps mid-clip; the yeast that had settled looks disturbed and pushed around right after the glucose goes in, as if bumped, then abruptly resettles; a bubble freezes mid-rise and then jumps forward; the shadow under a container swings to a different direction or gets noticeably brighter/dimmer with no light source change to explain it.
level_3: The two containers stay put beside each other at the same height and spacing the whole time; no container or its contents flicker out or double up; the glass stays clear throughout with no sudden opacity change; bubbles move upward without freezing, skipping, or reversing; neither container's outline warps and the liquid surface stays flat except where a bubble breaks it.
level_4: Building on the 3-point bar, the shot itself does not visibly pan, tilt, zoom, or drift sideways at any point a viewer would notice; the settled yeast layer stays undisturbed except right where a bubble is forming and lifting off; ripples on the liquid surface only ever trace back to a bubble breaking the surface, not to some unrelated wave or shake.
level_5: Building on the 4-point bar, every frame reads as the next logical moment after the last (the glucose enters the right container, the water near it clouds briefly, then the first bubbles appear there, all within the same unbroken shot), with no dropped or repeated frame, and any motion blur on the rising bubbles or the hand matches how fast they're actually moving.