Haemoglobin provides an adaptive advantage to an endotherm in a cold environment because it allows (A) more oxygen to be dissolved in plasma - HSC - SSCE Biology - Question 19 - 2012 - Paper 1

The correct answer is (C) more energy to be available to the organism.

Explanation: In cold environments, an endotherm must maintain its body temperature. Hemoglobin's primary role is to transport oxygen from the lungs to the tissues. Increased oxygen availability allows for more efficient aerobic respiration, ultimately leading to the production of more ATP (adenosine triphosphate), which is vital for energy. Consequently, enough energy is made available to support metabolic functions necessary for survival in the colder environment.