#Question id: 19333
#Unit 12. Applied Biology
#Question id: 641
#Unit 1. Molecules and their Interaction Relevant to Biology
Which of the following does NOT describe a mechanism that cells use to regulate enzyme activities?
A. Cells control enzyme activity by phosphorylation and dephosphorylation.
B. Cells control enzyme activity by the binding of small molecules.
C. Cells control the rates of diffusion of substrates to enzymes.
D. Cells control the rates of enzyme degradation.
E. Cells control the rates of enzyme synthesis.
F. Cells control the targeting of enzymes to specific organelles.
#Question id: 19328
#Unit 12. Applied Biology
#Question id: 371
#Unit 1. Molecules and their Interaction Relevant to Biology
How many milliliters of a 2.0 M solution of boric acid must be added to 600 mL of a solution of 10 mM sodium borate in order for the pH to be 9.45? (pKa of boric acid = 9.24)
#Question id: 13131
#Unit 10. Ecological Principles
Biologists performed an experiment with flies to examine the effects of population size on the maintenance of genetic variation and on egg-to-adult survival. From a large source population, they randomly assigned eggs to three experimental populations of size N, equal to 20, 60, and0100. For later generations, they collected N eggs from each population and moved them into identical vials that co0ntained f2re0sh me4d0ium. Th6e0y coun8te0d the number of adult flies that emerged and used tissue samples from the adults for genetic analyses. Genetic variation was measured by scoring alleles at several polymorphic loci and expressed as the average number of alleles at those loci. The results are summarized in Figure 1 and Figure 2 below.
The numbers of adult flies that emerged from the three populations in the first generation are closest to which of the following?
