Which statement best describes the role of a gene in the production of an organism traits? a. one strand of a gene serves as the template for making an mrna molecule. b. a gene has versions called alleles so that it can produce different traits. c. a gene unwinds and becomes a template that organizes amino acids. d. one strand of a gene exits the nucleus and goes to a ribosome to pair with a protein.

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:

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.