BIOLOGY 181 REVISION EXAM 2025/2026 QUESTIONS AND
ANSWERS GRADED A+
✔✔The emerging field of ______ biology focuses on studying living organisms as a
whole as well as understanding the workings of the parts of an organism. - ✔✔Systems
Biology
✔✔True or false: A hypothesis can be proven correct if it is tested enough times. -
✔✔False
✔✔Of the following statements about hypotheses, which are TRUE (choose all that
apply)? - ✔✔1. A hypothesis can be disproved, but it cannot be proved correct.
2. An accepted hypothesis may be false.
3. When scientists accept a hypothesis that means it is in agreement with all the
available evidence.
✔✔Which of the following would be an example of an objective observation? - ✔✔My
cat has 4 legs.
✔✔Proteins are polymers composed of - ✔✔Amino Acids
✔✔When biuret reagent is added to a solution containing protein, the solution turns pink
or purple. In the absence of protein, the solution is blue. Biuret reagent was added to
solutions that may or may not contain protein. The data can be seen in the table below.
What conclusion can be drawn from this data?
Tube Result A Blue B Blue C Blue D Purple - ✔✔Tube D contains protein, while tubes
A, B, and C do not.
✔✔When biuret reagent is added to a solution containing protein, the solution turns pink
or purple. In the absence of protein, the solution is blue. Biuret reagent was added to
solutions that may or may not contain protein. The data can be seen in the table below.
What is the dependent variable in this experiment?
Tube Result A Blue B Blue C Blue D Purple - ✔✔the color change from blue to purple
✔✔An unknown liquid sample is tested for chemical composition. You receive the
following results: iodine test = yellow; biuret test = blue; Benedict's test = blue; and
paper lipid test = clear. Which of the following are present in this sample? (Select all that
apply) - ✔✔None of these are present.
✔✔An unknown sample is tested for chemical composition. You receive the following
results: iodine test = purple; biuret test = blue; Benedict's test = green; and paper lipid
test = greasy spot. Which of the following are present in this sample? (Select all that
apply) - ✔✔Starch, Sugar, and Lipids
, ✔✔Which reagent is used to detect the presence of protein? - ✔✔Biuret
✔✔During the paper test, solution 2 left a faint stain behind and was determined to be
milk while solution 4 left a very definite and greasy stain behind and was determined to
be oil. What can be concluded about the lipid content of milk? - ✔✔It contains a lower
concentration of lipids than oil.
✔✔Emulsifiers are - ✔✔Molecules with a polar end and a nonpolar end that can be
used to disperse lipids into polar liquids such as water.
✔✔Which classes of macromolecules have a significant role in energy storage? (Select
all that apply) - ✔✔Lipids and Carbohydrates
✔✔Which group of molecules are insoluble in water? - ✔✔Lipids
✔✔When testing for starch within the potato and onion, the test tube containing potato
turned purple while the test tube containing onion turned orange. What can you
conclude about the amount of starch in these two vegetables? - ✔✔The potato
contained a higher concentration of starch than the onion.
✔✔Which molecule is hydrolyzed (digested) by amylase? - ✔✔starch
✔✔Which color change represents a positive reaction for the presence of starch using
the iodine test? - ✔✔yellow to purple
✔✔While testing an unknown solution a student adds Benedict's reagent and watches
as the contents of the test tube turn green. The student then added amylase and heats
the test tube. This causes the contents to turn red. Which of the following conclusions
could the student make? - ✔✔The solution contained both simple sugars and starch.
✔✔Which of the following are functions of carbohydrates? (Select all that apply) -
✔✔storage of energy, structural support, and signaling molecules (such as hormones or
neurotransmitters)
✔✔The formation of a green color after heating with Benedict's reagent indicates that a
sample contains simple sugars. - ✔✔True
✔✔Which reagent is used to detect the presence of simple sugars? - ✔✔Benedict's
✔✔Which of the following tests requires heating prior to observing results? -
✔✔Benedict's Test
ANSWERS GRADED A+
✔✔The emerging field of ______ biology focuses on studying living organisms as a
whole as well as understanding the workings of the parts of an organism. - ✔✔Systems
Biology
✔✔True or false: A hypothesis can be proven correct if it is tested enough times. -
✔✔False
✔✔Of the following statements about hypotheses, which are TRUE (choose all that
apply)? - ✔✔1. A hypothesis can be disproved, but it cannot be proved correct.
2. An accepted hypothesis may be false.
3. When scientists accept a hypothesis that means it is in agreement with all the
available evidence.
✔✔Which of the following would be an example of an objective observation? - ✔✔My
cat has 4 legs.
✔✔Proteins are polymers composed of - ✔✔Amino Acids
✔✔When biuret reagent is added to a solution containing protein, the solution turns pink
or purple. In the absence of protein, the solution is blue. Biuret reagent was added to
solutions that may or may not contain protein. The data can be seen in the table below.
What conclusion can be drawn from this data?
Tube Result A Blue B Blue C Blue D Purple - ✔✔Tube D contains protein, while tubes
A, B, and C do not.
✔✔When biuret reagent is added to a solution containing protein, the solution turns pink
or purple. In the absence of protein, the solution is blue. Biuret reagent was added to
solutions that may or may not contain protein. The data can be seen in the table below.
What is the dependent variable in this experiment?
Tube Result A Blue B Blue C Blue D Purple - ✔✔the color change from blue to purple
✔✔An unknown liquid sample is tested for chemical composition. You receive the
following results: iodine test = yellow; biuret test = blue; Benedict's test = blue; and
paper lipid test = clear. Which of the following are present in this sample? (Select all that
apply) - ✔✔None of these are present.
✔✔An unknown sample is tested for chemical composition. You receive the following
results: iodine test = purple; biuret test = blue; Benedict's test = green; and paper lipid
test = greasy spot. Which of the following are present in this sample? (Select all that
apply) - ✔✔Starch, Sugar, and Lipids
, ✔✔Which reagent is used to detect the presence of protein? - ✔✔Biuret
✔✔During the paper test, solution 2 left a faint stain behind and was determined to be
milk while solution 4 left a very definite and greasy stain behind and was determined to
be oil. What can be concluded about the lipid content of milk? - ✔✔It contains a lower
concentration of lipids than oil.
✔✔Emulsifiers are - ✔✔Molecules with a polar end and a nonpolar end that can be
used to disperse lipids into polar liquids such as water.
✔✔Which classes of macromolecules have a significant role in energy storage? (Select
all that apply) - ✔✔Lipids and Carbohydrates
✔✔Which group of molecules are insoluble in water? - ✔✔Lipids
✔✔When testing for starch within the potato and onion, the test tube containing potato
turned purple while the test tube containing onion turned orange. What can you
conclude about the amount of starch in these two vegetables? - ✔✔The potato
contained a higher concentration of starch than the onion.
✔✔Which molecule is hydrolyzed (digested) by amylase? - ✔✔starch
✔✔Which color change represents a positive reaction for the presence of starch using
the iodine test? - ✔✔yellow to purple
✔✔While testing an unknown solution a student adds Benedict's reagent and watches
as the contents of the test tube turn green. The student then added amylase and heats
the test tube. This causes the contents to turn red. Which of the following conclusions
could the student make? - ✔✔The solution contained both simple sugars and starch.
✔✔Which of the following are functions of carbohydrates? (Select all that apply) -
✔✔storage of energy, structural support, and signaling molecules (such as hormones or
neurotransmitters)
✔✔The formation of a green color after heating with Benedict's reagent indicates that a
sample contains simple sugars. - ✔✔True
✔✔Which reagent is used to detect the presence of simple sugars? - ✔✔Benedict's
✔✔Which of the following tests requires heating prior to observing results? -
✔✔Benedict's Test
