Read the following passage and answer the item that follows. Your answer to this item should be based on the passage only.

Scientists used lab-grown organoids, small clusters of human cells that mimic early tissue development, to study how microplastics affect cell signalling during differentiation. By tracking gene activity as the organoids specialised into muscle-like and nerve-like tissue, the team detected disrupted signalling pathways when microplastic particles were introduced, pathways already linked in other research to developmental disorders. The organoid approach allowed testing at a level of detail not possible in whole-animal studies.

On the basis of the passage given above, the following assumptions have been made:

1. Microplastics may interfere with tissue development in vivo, not only in laboratory organoids.

2. Organoid models can substitute entirely for all future whole-animal research.

3. Lab-grown tissue models can help evaluate the physiological risks of environmental contaminants.

Which of the above assumptions are valid?