Genotype

Phenotype

Interspecific Variation

Intraspecific Variation

Mutations

Pathogen

Infection

Gas-exchange system

Genes

Tumour

Enzymes

Aerobic Respiration

Respiration

Nucleus

Cell Membrane

Mitochondria

Ribosomes

Cell wall

Root hair cells

White Blood Cells

Microvilli

Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Golgi Apparatus

Lysosome

Red Blood Cells

Osmosis

Diffusion

Chromosomes

Alleles

DNA

Species