Love actions must be reciprocated?

Exchange: We offer and ask/expect to receive. We pay (give money in exchange of) for something (trade). We offer something for something else (money, applause, recognition, award, certificates etc).
Do we (give) love in exchange of love or what? Must love be exchanged, reciprocated and mutual?
Jesus, Christianity, Old Testament “love one another”. Other religions and philosophies “love” .
Is love a need, medium for consummation? A lack of something? Is it in our DNA?
Loving living and/or non-living things, your occupation/ profession. Fond of something, Hobbies, interests.
Love of learning, beauty, ideas, your country.
Do we perceive those who are not friends/we love of ours as enemies and why? Is it needed?
Are there people vacant of love, not able to love?
Is parents’ love a real love? Do animals love something, or just their mate, or are they attracted by instinct or physically only?
Does charity contain love?