Answer: The concentration of reducing ends is too small to detect.
Step-by-step explanation:
The reducing sugar can be defined as the sugar that is capable of acting as a reducing agent because it possesses an aldehyde group and a ketone group. Some polysaccharides are reducing sugars but all the monosaccharides are reducing sugars. The polysaccharide with reducing sugars do not give a positive test for reducing sugars because the concentration or amount of reducing ends is too small to detect.