Previously humans did not know that plants too have male and female gender distinctions. Botany states that every plant has a male and female gender. Even the plants that are unisexual have distinct elements of both male and female. "'And has sent Down water from the sky.' With it have We produced Diverse pairs of plants Each separate from the others." [Al-Qur'an 20:53]
FRUITS CREATED IN PAIRS, MALE AND FEMALE
"And fruit Of every kind He made In pairs, two and two." [Al-Qur'an 13:3]
Fruit is the end product of reproduction of the superior plants. The stage preceding fruit is the flower, which has male and female organs (stamens and ovules). Once pollen has been carried to the flower, they bear fruit, which in turn matures and frees its seed. All fruits therefore imply the existence of male and female organs; a fact that is mentioned in the Qur'an.
In certain species, fruit can come from non-fertilized flowers (parthenocarpic fruit) e.g. bananas, certain types of pineapple, fig, orange, vine, etc. They also have definite sexual characteristics.
EVERYTHING MADE IN PAIRS
"And of everything We have created pairs." [Al-Qur'an 51:49]
This refers to things other than humans, animals, plants and fruits. It may also be referring to a phenomenon like electricity in which the atoms consist of negatively – and positively – charged electrons and protons.
"Glory to Allah, Who created In pairs all things that The earth produces, as well as Their own (human) kind And (other) things of which They have no knowledge." [Al-Qur'an 36:36]
The Qur'an here says that everything is created in pairs, including things that the humans do not know at present and may discover later.
(from "The Quran and Modern Science, Compatible or Incompatible?" by "Dr. Zakir Abdul Karim Naik" published by Darussalam)