AP Biology Midterm Questions and
Answers
Which of the following best describes what causes water molecules to exhibit
properties such as cohesive and adhesive behavior?
✓ ~~~Water molecules are polar, having partially positive and partially negative ends.
Which statement correctly compares the pH of water to that of other substances?
✓ ~~~The pH of water is neutral; it is higher than the pH of acids and lower than the pH of
bases.
The slight negative charge at one end of one water molecule is attracted to the slight
positive charge of another water molecule. What is this attraction called?
✓ ~~~A hydrogen bond
Which of the following best explains how water is able to dissolve ionic substances?
✓ ~~~The positive and negative charges of the water molecule pull on the negative and
positive ends of the ionic molecule to break them apart.
During winter's freezing temperatures, some plants can remove water from their cells
to reduce the amount of water that will freeze inside them. Why would plants need to
do this?
✓ ~~~The expansion of excess water as it turns to ice inside the cells would break the cells
apart.
Which of the following best describes how the density of water differs from that of
other substances?
, ✓ ~~~The density of water depends on its temperature, unlike other substances.
Carbon atoms are able to
✓ ~~~bond with other carbon atoms to form long chains
What is true of carbon atoms?
✓ ~~~They can form up to four covalent bonds.
Carbon atoms can form
✓ ~~~four single covalent bonds
Why should farmers plant crops that improve the levels of nitrogen in the soil during
the winter?
✓ ~~~These crops have root nodules that contain bacteria.
Bacteria in the soil convert ammonia into a form that can be reabsorbed by a plant.
Which geochemical cycle does this sequence describe?
✓ ~~~Nitrogen cycle
Why are bacteria an essential part of the nitrogen cycle?
✓ ~~~Bacteria are responsible for fixing nitrogen into usable forms for other organisms.
Carbohydrates are polymers composed of linked monosaccharides. Which of the
following is a true statement about polymers?
✓ ~~~Proteins, carbohydrates, and nucleic acids are all polymers.
,What process links monomers of carbohydrates?
✓ ~~~Spontaneous glycosidic links
What are the functional units of a monosaccharide?
✓ ~~~Carbonyl and hydroxyl groups
Suppose you have an unknown chemical reaction involving carbohydrates. What is
one way to test whether the reaction is dehydration synthesis or hydrolysis reaction?
✓ ~~~Determine whether water is formed.
Which of the following correctly lists the functions lipids serve in the body?
✓ ~~~Energy storage, cell structure, signaling
One of the properties of cellulose is that it is not soluble in water. What would
happen if cellulose was water-soluble?
✓ ~~~Cell walls of plants would no longer maintain their rigid form.
Why is the sequence of nucleotides important to the properties of a nucleic acid?
✓ ~~~It retains and transmits important biological information.
Why is the sequence of amino acids important to the properties of a protein and
determination of the protein produced?
✓ ~~~It determines how the biochemical folds into a three-dimensional structure.
, Why is the sequence of monosaccharides important to the properties of a
carbohydrate?
✓ ~~~It stores energy and provides structural support for cells.
How do components of a DNA molecule influence its physical properties?
✓ ~~~Deoxyribose and phosphate, linked by phosphodiester bonds, form repeating units to
make up the backbone of DNA.
How do RNA's subcomponents affect its properties?
✓ ~~~Base pairing occurs within an RNA molecule to give RNA the three-dimensional
shape needed for specific functions.
What is the relationship between the sequence of DNA's subcomponents and the
properties of DNA?
✓ ~~~The nitrogenous base sequence along a segment of DNA determines the amino acid
sequence that will be produced.
Which of the following organelles contributes to cell functions by processing
proteins?
✓ ~~~Golgi Apparatus
Which of the following organelles helps to carry out the light-dependent reactions?
✓ ~~~Chloroplast
Which of the following organelles is responsible for detoxifying poisons in a cell?
✓ ~~~Smooth endoplasmic reticulum
Answers
Which of the following best describes what causes water molecules to exhibit
properties such as cohesive and adhesive behavior?
✓ ~~~Water molecules are polar, having partially positive and partially negative ends.
Which statement correctly compares the pH of water to that of other substances?
✓ ~~~The pH of water is neutral; it is higher than the pH of acids and lower than the pH of
bases.
The slight negative charge at one end of one water molecule is attracted to the slight
positive charge of another water molecule. What is this attraction called?
✓ ~~~A hydrogen bond
Which of the following best explains how water is able to dissolve ionic substances?
✓ ~~~The positive and negative charges of the water molecule pull on the negative and
positive ends of the ionic molecule to break them apart.
During winter's freezing temperatures, some plants can remove water from their cells
to reduce the amount of water that will freeze inside them. Why would plants need to
do this?
✓ ~~~The expansion of excess water as it turns to ice inside the cells would break the cells
apart.
Which of the following best describes how the density of water differs from that of
other substances?
, ✓ ~~~The density of water depends on its temperature, unlike other substances.
Carbon atoms are able to
✓ ~~~bond with other carbon atoms to form long chains
What is true of carbon atoms?
✓ ~~~They can form up to four covalent bonds.
Carbon atoms can form
✓ ~~~four single covalent bonds
Why should farmers plant crops that improve the levels of nitrogen in the soil during
the winter?
✓ ~~~These crops have root nodules that contain bacteria.
Bacteria in the soil convert ammonia into a form that can be reabsorbed by a plant.
Which geochemical cycle does this sequence describe?
✓ ~~~Nitrogen cycle
Why are bacteria an essential part of the nitrogen cycle?
✓ ~~~Bacteria are responsible for fixing nitrogen into usable forms for other organisms.
Carbohydrates are polymers composed of linked monosaccharides. Which of the
following is a true statement about polymers?
✓ ~~~Proteins, carbohydrates, and nucleic acids are all polymers.
,What process links monomers of carbohydrates?
✓ ~~~Spontaneous glycosidic links
What are the functional units of a monosaccharide?
✓ ~~~Carbonyl and hydroxyl groups
Suppose you have an unknown chemical reaction involving carbohydrates. What is
one way to test whether the reaction is dehydration synthesis or hydrolysis reaction?
✓ ~~~Determine whether water is formed.
Which of the following correctly lists the functions lipids serve in the body?
✓ ~~~Energy storage, cell structure, signaling
One of the properties of cellulose is that it is not soluble in water. What would
happen if cellulose was water-soluble?
✓ ~~~Cell walls of plants would no longer maintain their rigid form.
Why is the sequence of nucleotides important to the properties of a nucleic acid?
✓ ~~~It retains and transmits important biological information.
Why is the sequence of amino acids important to the properties of a protein and
determination of the protein produced?
✓ ~~~It determines how the biochemical folds into a three-dimensional structure.
, Why is the sequence of monosaccharides important to the properties of a
carbohydrate?
✓ ~~~It stores energy and provides structural support for cells.
How do components of a DNA molecule influence its physical properties?
✓ ~~~Deoxyribose and phosphate, linked by phosphodiester bonds, form repeating units to
make up the backbone of DNA.
How do RNA's subcomponents affect its properties?
✓ ~~~Base pairing occurs within an RNA molecule to give RNA the three-dimensional
shape needed for specific functions.
What is the relationship between the sequence of DNA's subcomponents and the
properties of DNA?
✓ ~~~The nitrogenous base sequence along a segment of DNA determines the amino acid
sequence that will be produced.
Which of the following organelles contributes to cell functions by processing
proteins?
✓ ~~~Golgi Apparatus
Which of the following organelles helps to carry out the light-dependent reactions?
✓ ~~~Chloroplast
Which of the following organelles is responsible for detoxifying poisons in a cell?
✓ ~~~Smooth endoplasmic reticulum
