Biology: cells, inheritance and evidence
Use the level of organization requested in the task: an organ contains tissues, and tissues contain cells. A typical plant cell may have a cell wall and a large vacuole, but a drawing does not establish that every plant cell has visible chloroplasts. Photosynthesis in chloroplast-containing tissues uses light energy to build organic material from carbon dioxide and water. Aerobic respiration releases usable energy through processes involving oxygen. Do not define every form of cellular energy release as requiring oxygen, because anaerobic pathways also occur.
In a simple one-gene model with complete dominance, an Rr-by-Rr cross has expected genotype proportions one-quarter RR, one-half Rr and one-quarter rr. The expected phenotype proportions are three dominant to one recessive only under those specified assumptions. A small observed family need not match the expected ratio. A dominant phenotype does not distinguish RR from Rr. In a testcross with rr, an Rr parent can by chance produce several dominant offspring in a row; the observation changes the evidence but does not logically prove the parent was RR.
Separate environmental effects from inherited differences when interpreting experiments. To compare light conditions, use comparable organisms, replication and controlled water, temperature and other relevant variables. A measured difference supports a causal explanation only to the extent that the design controls competing explanations. In food webs, arrows should have a stated meaning, commonly transfer of energy from food to consumer. Matter cycles through ecosystems, whereas energy enters, is transferred and is dissipated. Describe a concrete chain without implying that every organism has a single food source or that every ecosystem has the same fixed number of trophic levels.