In plants that undergo double fertilization, the structure that forms to nourish the seed is called the

In plants that undergo double fertilization, the structure that forms to nourish the seed is called the endosperm.

Explanation:

The process of double fertilization can be described as a phenomenon in which one of the sperm cells fertilizes the egg cell whereas another sperm cell joins with the two polar nuclei of the ovule

The sperm cell and the egg cell will unite and form the zygote.

On the other hand, the sperm which fuses with the two polar nuclei will form the endosperm.

The endosperm can be described as a nourishing tissue which provides the embryo with nutrients so that it can develop and mature.