Are all plankton microscopic? aquatic science

An example of internal feedback working to maintain homeostasis is your a. decreased respiration rate when you are studying b. decreased heart rate when you are sad c. increased respiration rate when your muscles need more oxygen d. increased heart rate when your lungs need more oxygen

If assuming tasting ptc as a simple gene trait, what other genotype would you select to put in this missing genotype box that could result in this phenotype

What is used to keep track of the gamates and possible offsprings combination