1. Explain How Villi Is Adapted to Glucose.
 Villi has many microvilli, so increase surface area for better absorption.
 Each villus has only one thick epithelial cell, thus, diffusion path way is short to
absorb glucose efficiently.
 Every microvillus has lacteal which absorbs fatty acid and glycerol and has many
blood capillaries to absorb glucose and amino acid.
2. A student is given two samples of carbohydrates.
He tests to see if one is glucose and the other one is starch.
Describe the two chemical tests he should use to identify each carbohydrate.

He tests with iodine solution and Benedict's solution to each carbohydrate.
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First practical, he drops iodine solution to the starch on a spotting tile, and then
iodine reacts with the starch, forming a very blue- black color. By the color result,
he can prove that starch exists.

Second practical, he adds Benedict's solution in the glucose test tube. Next, the
test tube is placed in a water bath and heated with Bunsen burner. A few second
later, solution color changed to the brick-red due to the presence of glucose.
3. Wasps defend themselves from predators by using sting. This means that predators
avoid attacking wasps.
Arsh borers look very similar to wasps.
Use your knowledge of natural selection to explain why Arsh borers have evolved
look like wasps.
- Arsh borers are gradually look very similar by the process of mutation.
- They have also variation; they look similar with wasps.
- By these reasons, Arsh borers can survive only that are very similar to wasps.
- When the survived Arsh borers reproduce, they will pass their genes to their babies.
- And then, the survived Arsh borers population is increase.
- Thus, predators don’t eat them anymore.