Steroid hormones are hydrophobic and so are not soluble in the plasma (plasma is made up mostly of water). which type of protein would transport steroid hormones in the blood?

The steroids are insoluble in the plasma of the blood. The consistency of the plasma is mainly dominated by the water molecules; hence, transporting the hydrophobic molecule cannot be done through plasma.  

The plasma is also rich in many protein molecules, which are also known as the plasma proteins. These plasma proteins are the main molecules, which help in the transport of lipids and the steroid molecules in the blood.  These plasma proteins are albumin, prothrombin, fibrinogen, and the gamma globulins. Serum albumin is the main protein responsible for the transport of the steroid molecules.

haploid cells;

the supermassive black hole is in the middle of the galaxy.