Question

a genetic factor that is blocked by the presence of a dominant factor cross pollination recessive heredity dominant hybrid

Explanation:

To solve this, we analyze each option:

• "cross pollination" refers to a plant breeding method, not a genetic factor's type.
• "recessive" is defined as a genetic factor that is masked (blocked) when a dominant factor is present.
• "heredity" is the passing of traits, not a factor blocked by dominant.
• "dominant" is the factor that blocks others, not the blocked one.
• "hybrid" refers to an organism with mixed genes, not a blocked factor.

Answer:

B. recessive