#Question id: 53
#Unit 1. Molecules and their Interaction Relevant to Biology
Calculate the number of times the DNA of a modern E. coli cell has been copied accurately since its earliest bacterial precursor cell arose about 3.5 billion years ago. Assume for simplicity that over this time period, E. coli has undergone, on average, one cell division every 12 hours (this is an overestimate for modern bacteria, but probably an underestimate for ancient bacteria).
#Question id: 54
#Unit 1. Molecules and their Interaction Relevant to Biology
About 25 of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96% of living matter?
#Question id: 55
#Unit 1. Molecules and their Interaction Relevant to Biology
The standard free energy change for the reaction A → B is −15.0 kJ · mol−1. What is the equilibrium constant for the reaction at 25°C?
#Question id: 56
#Unit 1. Molecules and their Interaction Relevant to Biology
Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates, but not by other organisms such as bacteria or plants?
#Question id: 57
#Unit 1. Molecules and their Interaction Relevant to Biology
A(n) ________ has charge but negligible mass, whereas a(n) ________ has mass but no charge.
#Question id: 58
#Unit 1. Molecules and their Interaction Relevant to Biology
A covalent chemical bond is one in which ________.