[Campbell Biology P.502] The text explains that different forms of globin subunits are expre... | Practice Question

The text explains that different forms of globin subunits are expressed at various times during human development embryonic, fetal, and adult . What is the primary evolutionary advantage of this arrangement?

  • A: It allows for the production of a greater variety of amino acids, enhancing protein diversity.
  • B: It ensures that hemoglobin has optimal oxygen affinity for the varying physiological conditions encountered during different developmental stages.
  • C: It provides resistance to various pathogenic infections throughout the organism's lifespan.
  • D: It reduces the overall energy expenditure for hemoglobin synthesis throughout an individual's life.

Explanation

The text explicitly states that 'The different forms of each globin subunit are expressed at different times in development, allowing hemoglobin to function effectively in the changing environment of the developing animal. In humans, for example, the embryonic and fetal forms of hemoglobin have a higher affinity for oxygen than the adult forms, ensuring the efficient transfer of oxygen from mother to fetus.' This directly points to the advantage of optimized oxygen affinity.