i would say plants would feature more so in next years long questions as they were only in q.15 part c this year.
1.short qs , are notoriously hard to predict but three are basically easy enough- food,ecology,cell division
2. experiments-really need to know them all, theres revision book called essentials unfolded and they have done summaries of each exp at the back, which i find very helpful
3-long question- now this is where you need to be tactical with your study.
you are guaranteed essentially three topics,they are - ecology,genetics and biochemistry
btw genetics consists of crosses, genetic engineering,dna/rna and evolution and classification
biochemitry consists of photosyyntheisi,respiration and enzymes. for the final 3 long questions they are based on unit 3. i would study all plant cha´petrs, all microbiology chaptas (monera,fungi,viruses and amoeba) and then human reproduction.
if you study all topics above really well you should be in a good position to get H1. If you know these chapetrs well then move on to your excretion,circulation and endocrine system in that order.
So recap before christmas study your unit 1 -ecology and food, biochemitry and genetics. For unit 3 chaptas there is great notes on an instagram page called theleavingcertbible, i reallyt advise looking at it.
Good luck and remember exam questions are the key!