Pepsin, trypsin and chymotrypsin are substances that affect reaction rates, those can be defined as

Enzymes

Explanation:

Enzymes are those proteins which participate in a chemical reaction without being consumed in the reaction. These enzymes work as a catalyst which speed up the rate of the chemical reaction. The enzyme is responsible for converting the substrate into a product. Pepsin is an enzyme present in the stomach it is activated by hydrochloric acid it is a peptic enzyme which converts proteins into peptones, trypsin and chymotrypsin are the enzymes secreted by the pancreas and it is responsible for digestion of proteins.

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.

b. read the phase at the intersection of any given temperature and pressure.