Question

what is the main source of glucose for humans?

it is manufactured by the pancreas
from the food they consume
it is manufactured by cells
it is naturally occurring in the blood.

Explanation:

Analyze the biological origin of glucose

Humans are heterotrophs and cannot synthesize glucose from inorganic precursors via photosynthesis. Therefore, they must obtain glucose or its precursors from external dietary sources.

Evaluate the given options

• "It is manufactured by the pancreas": The pancreas produces hormones like insulin and glucagon to regulate blood glucose levels, but it does not manufacture glucose.
• "From the food they consume": Dietary carbohydrates (like starch and sugars) are digested and broken down into glucose, which is the primary external source of energy for humans.
• "It is manufactured by cells": While gluconeogenesis can produce glucose in the liver and kidneys during fasting, this is a metabolic backup rather than the primary daily source.
• "It is naturally occurring in the blood": Glucose circulates in the blood, but it must be constantly replenished from external sources (food) to maintain homeostasis.

Answer:

• (A) It is manufactured by the pancreas
• (B) From the food they consume (Correct answer)
• (C) It is manufactured by cells
• (D) It is naturally occurring in the blood.