Final answer:
There are three main types of hemoglobin in humans: HbA, HbA₂, and HbF.
Step-by-step explanation:
The hemoglobin in humans exists in three main types:
- HbA: Found in normal adult human beings - contains 2a and 2ẞ chains.
- HbA₂: Found in some human beings and is considered normal - contains 2a and 28 chains.
- HbF: Foetal hemoglobin - found in growing foetus - contains 2a and 2y chains.