The discovery of RNA self-splicing by T. Cech (1982) and others in Tetrahymena revealed that RNA can demonstrate autonomous catalytic properties. RNAs that undergo such splicing are often called .

Explanation:

Ribozymes is a ribonucleic acid (RNA) enzyme, which is made up only by RNA.

RNA self-splicing is discovered by T. Cech (1982).

They plays very important role in protein synthesis as , they are part of ribosomes. Ribozymes also plays very important role in  RNA splicing in gene expression. RNase P.

Example:

Peptidyl transferase 23S rRNA.

Leadzyme.

Group I and II introns , and there many other ribozymes.

explanation:

on disadvantage of hydroelectric power is the cost. another disadvantage of using hydroelectric power is finding a water source powerful enough to harvest hydroelectric power.

answer >   yes we do, women; have three holes, urethral opening(pee hole, vagina, and the women pee/girls pee out of the urethra like the men do; only they have a single opening to pee/ejaculate.   (sorry if i'm too forward with this, but this is for a biology class, isn't it? )

hope that !         : )