Answer:
sigmoid
Explanation:
The sigmoid shape of the dissociation curve is because
As the first oxygen molecule binds to haemoglobin, it increases the affinity for the second molecule of oxygen to bind. Subsequently, haemoglobin attracts more oxygen.
Answer: sigmoid
What was the investigation? But from my best guess I'm assuming it's the second option. This may be incorrect.
2.33 billion years ago.
Hope this helps <3
