This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET 2018, Subject name: Biochemistry
Most abundant form of pro-vitamin A is:- 
Select and explain. 
A. Beta carotene, B. Alpha-carotene, C. Retinol, D. Retinaldehyde
A: Beta carotene
Answer: A: Beta carotene 
Explanation: Carotenoids are provitamins of vitamin A which are present in plants. Most impoant carotenoid is beta carotene , which consists of two molecules of retinal joined end to end. ADDITIONAL READING ON VITAMIN A: There are three biologically active forms of Vitamin A: Retinol: necessary for reproductive system Retinal: involved in vision Retinoic acid: involved in growth and cellular differentiation Retinoids are all-natural/ synthetic compounds with Vitamin A like activity.