Correct option is B
EXPLANATION-
Statement 1- The 'snowflake yeast' experiment demonstrated the evolution of multicellularity through cell adhesion and programmed cell death.
Correct
The snowflake yeast experiment is a well-known laboratory model demonstrating the evolution of multicellularity via clonal cell adhesion and programmed cell death (apoptosis), enabling reproduction of multicellular clusters.
Statement 2 -The syncytial theory states that multicellular organisms arose through the aggregation of free-living unicellular forms.
Incorrect
This is not the syncytial theory. The statement describes the colonial theory, not the syncytial theory. Syncytial theory suggests that multicellularity evolved from a multinucleated single cell (syncytium), which later developed cellularization (membrane separation around nuclei).
Colonial theory (described here) involves aggregation of individual unicellular organisms.
Statement 3: Cadherin-based adhesion pathways played an important role in the evolution of multicellularity in plants.
Cadherins are animal-specific adhesion molecules.
In plants, different adhesion molecules like pectins and extensins are important, not cadherins.
However, based on typical framing, Statement 2 is still more fundamentally incorrect, as it mixes up two entire theories.
Statement 4 - Co-option of existing functions is hypothesized to have driven the evolutionary transition from undifferentiated multicellular clusters to differentiated tissues.
Correct
This is widely accepted in evolutionary biology — existing genes and pathways were co-opted for new multicellular roles like tissue differentiation.
So, the correct option is (b)
