The BIOS is what gives instructions to the computer on how to Boot.
The Boot table is by itself stored on the Booting Sector of an Physical extension attached to the Mobo called the HDD , it can be any other Physical device, like a PEN drive, a SSD, a HDD etc etc
The BIOS cannot be transferred to the HDD for the Startup process
HDDs (Conventional) consume more power and take longer to read and write due to physical moving parts in them.
SSDs on the other hand consume less power have faster reads and writes and thus are more time and power efficient when compared to conventional HDDs.