Answer:
a) 化 -> 旨 -> 明 -> 肪
化 KA, KE, ba(keru) - transform
旨 SHI, mune - purport, content, instruction
明 MEI, MYOU, aka(rui), a(keru) - bright
肪 BOU - animal fat
b) 誓 -> 詳 -> 養 -> 飯
誓 SEI, chika(u) - swear, pledge, vow
詳 SHOU, kuwa(shii) - detailed, full, familiar with
養 YOU, yashina(u) - rear, support, adopt
飯 HAN, meshi - cooked rice, food