Which could be referred to as secondary growth of stems?
a. growth at the ends of the stem
b. an increase in the width of the stem
c. an increase in the length of the internodes

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation: