The structure clearly is that you have multiple species accessible in a simple way. Merging of the cells will inevitably destroy this structure. The ultimate goal you might achieve transferring the multiple items into one cell is a kind of preservation of the view (in multiple lines).
You should consider again the reasons for merging. In most cases they are not valid. With respect to the typical functionality of spreadsheets merging of cells is mostly evil. If you just are arranging some entries for a view to print it later, there is no reason for merging since the cell grid is not printed by default. (Expressly not recommended: You can also suppress it for the screen view.) Creating a printable border for the cell range would definitely be the better solution as compared with merging.
As far as I know there is no way to change the delimiter inserted on merging with ‘Yes’ answered to the prompt which is a space (ASCII 32). This would be needed for getting the result you want to achieve since the linefeed inside a cell is made by inserting an LF character (ASCII 10).
There is, however a recently implemented function TEXTJOIN which should be capable to get your desired result in another cell based on a formula without merging and using ‘Optimal Height’ instead. Unfortunately this new function has still some flaws.
The attached example is demonstrating a solution based on the new TEXTJOIN made with a trick and an alternative solution by the user function “MyTextJoin” coded by me some time ago (in BASIC) for the same purpose and not suffering from the same flaws.
(Editing:)
My answer to the original question is still “Not at all!”. The abstraction stressed above that it is, strictly spoken, impossible, aside, we may focus on something coming near to the assumed intentions. @mark_t already gave a hint, I will attach this new example also containing some explanations.
Please also note: ‘Calc’ originates from “calculations” spreadsheets were originally made for. If you are decisive to not calculate at all with your data (not even a concatenation of texts), you may consider to use a table in a ‘Writer’ document for your purposes. See also this example.
Also in Calc you may enter your list from the beginning in to one cell hitting Ctrl+Enter to insert line breaks.