When crossing tomatoes with a red color of the fruit, with plants that have yellow fruits, all the offspring have red fruits.

When crossing tomatoes with a red color of the fruit, with plants that have yellow fruits, all the offspring have red fruits. 1) What is the genotype of the crossed plants? 2) What is the dominant feature? 3) What pattern is manifested in such a crossing?

It is worth changing the order of the questions:
2) Considering that the result of crossing red and yellow tomatoes is red offspring, then red is a dominant trait (A), yellow is a recessive trait (a).
1) Based on the 100% uniformity of the offspring, we determine that the plant genotype is homozygous, namely: red tomato – AA, yellow – aa. In confirmation, we will consider the crossing scheme, from which it is clear that all the offspring are red in terms of the phenotype.
3) With such a crossing, Mendel’s first law is observed, also known as the law of uniformity of hybrids.