What is the main difference between prokaryotic and eukaryotic cells?
Prokaryotic cells can carry out more complex functions.
Prokaryotic cells have a nucleus and eukaryotic cells do not.
Eukaryotic cells have a nucleus and Prokaryotic cells do not.
Eukaryotic cells are found in single cell organism.

The scheme below is from a series of reactions that are part of a synthesis of vitamin a. answer the following questions with reference to this scheme. (i) what is "reagent a"? (ii) draw a step-by-step mechanism which explains the formation of compound c from compound b (iii) which reagents would you use to form compound e from compounds c and d (reagents b and c)? for each reagent suggested above in (ii) explain the role of the reagent in the reaction to (iv) form compound e. you may wish to do this by drawing a mechanism. 1. addition of reagent a но reagent a 2. н, о" thо oh нон-с compound a. compound b. compound c .ch-оh 1. reagent b "сно 2. reagent c сh oh compound e. compound d.

Calculate the concentration of all species in a 0.165 m solution of h2co3.

In medium-sized stars such as the sun, nuclear fusion almost always means the fusing of nuclei to form , but larger stars can produce elements as heavy as