Those who do BTEC are not stupid - ik someone who does BTEC applied sci and math, she is rlly clever (9s in both math and cs), and a BTEC business + Math student who is smart as well (9 in math, i believe, or an 8)
You should check ur sixth form requirements for biochem a levels, and then the btec, then think about which one is more realistic for you to get into. If the requirement is a 7 for biochem a levels, and a 4 in btecs, and predicted a 5, then its more realistic to get 4s rather 7s. yes, you might also get 7s, but what if you dont?