Answer: Polygenic means that most traits are controlled by an additive effect of two or more genes on a single phenotype.
Explanation: Polygenic inheritance or quantitative characters are those that vary in the population along a continuum. For example, height, skin color, etc.
Often, penetrance, pleiotropy, epistasis, expressivity and environmental factors are involved in producing a continuous distribution of phenotypes.
Traits such as height that show a continuous range of variation and do not behave in a single Mendelian fashion are known as quantitative or complex traits.
the process by which plants and animals make their own food
Because people may make fun of you or call you some terrible things because stds are often linked by sleeping around (obvi not always true but that’s what people make it out to be)
and i’m good lol you?
Oxygen and carbon dioxide travels to and from tiny air sacs in the lungs, through the walls of the capillaries, into the blood. Blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs.

I'm not exactly sure what specifically you are asking for in relationship to balancing equations, but I have some examples with working out so you can examine them and try to go through the steps with them.
Hope this helps! <3