Final answer:
Developmental adaptation refers to irreversible changes shaped by genetic factors or gene expression during an organism's life, while physiological adaptation consists of reversible changes in an organism's physiology in response to environmental triggers. Therefore the correct answer is 'Developmental is irreversible, physiological is reversible'.
Step-by-step explanation:
The difference between developmental and physiological adaptation lies in the nature and permanence of the changes. Developmental adaptation is generally irreversible and involves changes that occur during an organism's life due to genetic factors or changes in gene expression. This type of adaptation, once acquired, typically remains a part of the organism's structure or function throughout its life. Examples include the development of thicker fur in animals living in colder climates during their growth period or increased muscle mass as a result of regular physical training.
In contrast, physiological adaptation is often reversible and involves immediate, temporary changes in an organism's physiology that enable it to cope with environmental stressors. These adaptations are not genetic changes but are responses to triggers in the environment, such as the increased heart rate in response to a threat or the immune response to pathogen exposure. Once the environmental stressor is removed, the physiological changes can also be reversed.