Question

what will happen if a pea plant with brown and green seeds and plant with round and yellow seeds are coloured

Answer 1

Turns out they have yellow peas because the yellow version, Y, is dominant over the recessive green version, y. Y always wins out over y: When a pea plant makes seeds, only one of its two copies of the color gene goes into the seed. So if you have two green pea plants, each can only pass a green version.