JSFiddle - React, Tailwind, and code Playground

HTML

<div id="transgenic_div">
    <p><a class="transgenic_button" data-id="56">item number 56</a></p>
    <p><a class="transgenic_button" id="57">item number 57</a></p> etc
</div>

JavaScript

$('#transgenic_div').click(function(e) {
    var selected_transgenic_id = $(e.target).attr("data-id"); // or e.target.id
    alert(selected_transgenic_id);
});