If you were running a marathon which type of muscle fibers would be most useful to you?

slow-twitch

Slow twitch muscle fibres: Contract slowly, but keep going for a long time. Fast twitch muscle fibres: Contract quickly, but rapidly get tired. Endurance or speed. Slow twitch muscle fibres are good for endurance activities like long distance running or cycling. They can work for a long time without getting tired

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.