Answer:
The substance that is affected is haemoglobin
The term for monohybrid cross parents (or pure breds) is Homozygous. :)
<span>the way that Jenner form his hypothesis from this observation is : he asked what would happen if he deliberately inoculated someone with cowpox fluid from another person
based on that observation he crated an experiment which later proof that you can't get another pox if you already experienced it once</span>
