If an organism used glycolysis (Embden-Meyerhof-Parnas pathway) to break down glucose and produce ATP but was unable to subsequently use fermentation or an electron transport chain (respiration), what problem would develop?

NAD+ would not be able to regenerate and glycolysis would stop.

Explanation:

During glycolysis, two NAD+ molecules become reduced to NADH.

If no fermentation or respiration occurred, NADH would accumulate and NAD+ would exhaust, so glycolysis would stop.

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.