Regarding his experiments with pea plants, Mendel hypothesised that

1. Characters were carried as traits and an organism always carried a pair of factors for a character. 

2. The distinguishing traits of the same character were present in the population of an organism. 

3. The traits shown by the pea plants must be in the seeds that produced them. 

4. The seeds must have obtained by the traits from the parent plants.

His assumptions made to explain his observations are:

 Assumption 1: 

Every pea plant has two ‘factors’ which are responsible for producing a particular property or trait. 

Assumption 2: 

During reproduction one ‘factor’ from each parent is taken to form a new pair in the progeny. 

Assumption 3: 

One of these will always dominate the other if mixed together.

Laws made from his experiments: 

1. Law of Dominance: Among a pair of alleles for a character, only one expresses itself in the first generation as one of the allele is dominant over the other. 

2. Law of Segregation: Every individual possesses a pair of alleles for any particular trait and that each parent passes a randomly selected copy of only one of these to its offspring. 

3. Law of Independent Assortment: In the inheritance of more than one pair of characters the factors for each pair of characters assorts independently of the other pairs.