Question

What is the theory of particulate inheritance?

Answer 1

The theory of particulate inheritance states that discrete "particle" are passed from parents to offspring. While Mendel used the term particles, we now know that these particles are actually genes. Mendel also knew that particles may not be present in every generation, but they remain and keep their ability to be expressed in later generations.
For example,
Below is a Punnet square showing the parental generation and the particle the $F1$ generation (offspring of parents) inherits. The $F_1$ progeny has both the particles for smooth as well as wrinkled seeds, but only smooth is expressed. While, both smooth and wrinkled are expressed in the $F_2$