How do flowering plants reproduce by fertilization if they are immotile?
fertilization takes place in their roots.
o they conjugate with plants nearest them.
insects and other organisms carry pollen to other flowers.

Immotile flowering plants  accomplish fertilization with the help of Insects and other pollen from organisms that carry pollen to other flowers.

Explanation:

The transfer of pollen from anther to the stigma of flower is called pollination.Pollination is of two types: a) Self pollination    b) cross-pollinationTransfer of  pollen from anther to the stigma of same flower or flower of same plant is called self pollination.Transfer of pollen from anther to the stigma of different plant is called Cross-pollination.Pollination is the process by which angiosperms carry out sexual reproduction.Since, plants are immobile they need some agents for pollination  like, insects birds, wind, water etc

He used pea plants to study the patterns of heredity.