I received seeds from various produces as a gift. They are in sealed paper bags, but they occupy a lot of space and I was thinking about opening the bags and putting the seeds into small transparent plastic containers. Is this a good way to store and not compromise them? If not, what is the preferred alternative?
Things that are bad for seeds in storage are:
If the plastic containers are airtight and you are going to store them in a cool, dark, dry place, then it should be ok.
The best thing to do would be to ensure that they are thoroughly dry first -- you can use a desiccant like silica gel in the container. But if you plan to use the seeds soon, and they were properly dried before they were given to you, and the bags they are in haven't gotten damp/humid, then you may be ok.
Keeping them in the paper bags lets you be able to write the name/variety of them on the bag.
Long term storage of most vegetable and grains seeds would be to put them into a cool and dry environment. And longer storage happens when oxygen is removed from the container. This is why grains for long term storage will have air replaced with pure nitrogen.