Is it correct to conclude that the Qur’ān mentions that everything has been created in pairs, while science confirms that some creatures are asexual. Please clarify and also what is the purpose of this paired-creation?
Yes it has been said so in the Qur’ān that everything has been created in pairs:
وَمِن كُلِّ شَيْءٍ خَلَقْنَا زَوْجَيْنِ لَعَلَّكُمْ تَذَكَّرُونَ (٤٩:٥١)
And We have made pairs of everything so that you may take heed. (51:49)
However, what the Qur’ān states is a general principle without taking exceptions into account. Remember the Qur’ān is not delineating a fact of science; it is merely directing the attention of the people that everything is created in pairs in general. A member of one pair when taken individually is incomplete and purposeless. It is only when both members of a pair are considered that both of them become meaningful since both compliment each other in some manner or the other. Commonly observed pairs are man and woman, sun and moon, sky and earth. Now the purpose of this delineation is to show that just as man is incomplete without a woman; similarly this world also has a counterpart without which it would seem meaningless. It would seem to be a place of oppression and injustice, for example. On the other hand, when this world is viewed together with a Hereafter, it becomes meaningful and purposeful. Otherwise, we find it to be a place where many things and phenomena are inexplicable.