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AP BIOLOGY FIRST SEMESTER FINAL
PRACTICE AND REVIEW EXAM 2026 |
ALL QUESTIONS AND CORRECT
DETAILED ANSWERS | A GRADED |
NEW AND REVISED
What is the difference between the 5' end vs. 3' end of a polynucleotide
strand? - ANSWER- A key feature of all nucleic acids is that they have
two distinctive ends: the 5' (5-prime) and 3' (3-prime) ends. This
terminology refers to the 5' and 3' carbons on the sugar. For both DNA
(shown above) and RNA, the 5' end bears a phosphate, and the 3' end a
hydroxyl group.
What is the difference between a saturated vs. unsaturated fatty acid? -
ANSWER- Saturated fatty acids are solid at room temperature, while
unsaturated fatty acids are liquid at room temperature. This is because
saturated fats have no double bond between molecules, which means
there are no gaps and the fat is saturated with hydrogen molecules. On
the other hand, unsaturated fats have double bonds, which break up the
chain of hydrogen molecules and create gaps, allowing the fats to
liquefy at room temperature. Unsaturated is better for you
What cell parts differ between a prokaryotic cell vs. a eukaryotic cell? -
ANSWER- Eukaryotic cells contain membrane-bound organelles, such
as the nucleus, while prokaryotic cells do not. Differences in cellular
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structure of prokaryotes and eukaryotes include the presence of
mitochondria and chloroplasts, the cell wall, and the structure of
chromosomal DNA.
Large numbers of ribosomes are present in cells that specialize in
producing what type of molecules? - ANSWER- proteins
Which structure is the site of the synthesis of proteins that may be
exported from the cell? - ANSWER- Endoplasmic reticulum with
attached ribosomes is called rough ER. The attached ribosomes make
proteins that will be used inside the cell and proteins made for export out
of the cell. There are also ribosomes attached to the nuclear envelope.
What is probably the most common route for membrane flow in the
endomembrane system? - ANSWER- rough ER -> vesicles -> Golgi ->
plasma membrane
Grana thylakoids and stroma are all components found in what
organelle? - ANSWER- chloroplasts
How are the activities of mitochondria and chloroplasts similar and
different? - ANSWER- Differences:
Mitochondria-Converts chemical energy (sugar) into another form of
chemical energy (ATP), which is simpler and could be used by the cell.
Chloroplasts-Converts solar/light energy into chemical energy (sugar).
Similarities:
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-convert energy
-have its own DNA
-enclosed by two membranes
-oxygen (O2) and carbon dioxide (CO2) are involved in its processes
-both have fluids inside of them
How are plant and animal cell structures similar and different? -
ANSWER- Similar: Both eukaryotic cells, and contain membrane-bound
organelles such as the nucleus (nuclear envelope, nucleolus,chromatin),
mitochondria, endoplasmic reticulum (rough and smooth), golgi
apparatus, centrosomes, plasma membrane, ribosomes, cytoskeleton and
peroxisomes.
Differences: found in plant cells but not in animal- chloroplasts, central
vacuole, tonoplast, cell wall, plasmodesmata; found in animal but not in
plant- lysosomes, centrioles, flagella. [animal cells are larger than plant
cells]
Why do unsaturated fatty acids help keep membranes more fluid at
lower temperatures? - ANSWER- If unsaturated fatty acids are
compressed, the "kinks" in their tails push adjacent phospholipid
molecules away, which helps maintain fluidity in the membrane.
What kinds of molecules pass through a cell membrane most easily? -
ANSWER- small hydrophobic molecules
AP BIOLOGY FIRST SEMESTER FINAL
PRACTICE AND REVIEW EXAM 2026 |
ALL QUESTIONS AND CORRECT
DETAILED ANSWERS | A GRADED |
NEW AND REVISED
What is the difference between the 5' end vs. 3' end of a polynucleotide
strand? - ANSWER- A key feature of all nucleic acids is that they have
two distinctive ends: the 5' (5-prime) and 3' (3-prime) ends. This
terminology refers to the 5' and 3' carbons on the sugar. For both DNA
(shown above) and RNA, the 5' end bears a phosphate, and the 3' end a
hydroxyl group.
What is the difference between a saturated vs. unsaturated fatty acid? -
ANSWER- Saturated fatty acids are solid at room temperature, while
unsaturated fatty acids are liquid at room temperature. This is because
saturated fats have no double bond between molecules, which means
there are no gaps and the fat is saturated with hydrogen molecules. On
the other hand, unsaturated fats have double bonds, which break up the
chain of hydrogen molecules and create gaps, allowing the fats to
liquefy at room temperature. Unsaturated is better for you
What cell parts differ between a prokaryotic cell vs. a eukaryotic cell? -
ANSWER- Eukaryotic cells contain membrane-bound organelles, such
as the nucleus, while prokaryotic cells do not. Differences in cellular
,2|Page
structure of prokaryotes and eukaryotes include the presence of
mitochondria and chloroplasts, the cell wall, and the structure of
chromosomal DNA.
Large numbers of ribosomes are present in cells that specialize in
producing what type of molecules? - ANSWER- proteins
Which structure is the site of the synthesis of proteins that may be
exported from the cell? - ANSWER- Endoplasmic reticulum with
attached ribosomes is called rough ER. The attached ribosomes make
proteins that will be used inside the cell and proteins made for export out
of the cell. There are also ribosomes attached to the nuclear envelope.
What is probably the most common route for membrane flow in the
endomembrane system? - ANSWER- rough ER -> vesicles -> Golgi ->
plasma membrane
Grana thylakoids and stroma are all components found in what
organelle? - ANSWER- chloroplasts
How are the activities of mitochondria and chloroplasts similar and
different? - ANSWER- Differences:
Mitochondria-Converts chemical energy (sugar) into another form of
chemical energy (ATP), which is simpler and could be used by the cell.
Chloroplasts-Converts solar/light energy into chemical energy (sugar).
Similarities:
, 3|Page
-convert energy
-have its own DNA
-enclosed by two membranes
-oxygen (O2) and carbon dioxide (CO2) are involved in its processes
-both have fluids inside of them
How are plant and animal cell structures similar and different? -
ANSWER- Similar: Both eukaryotic cells, and contain membrane-bound
organelles such as the nucleus (nuclear envelope, nucleolus,chromatin),
mitochondria, endoplasmic reticulum (rough and smooth), golgi
apparatus, centrosomes, plasma membrane, ribosomes, cytoskeleton and
peroxisomes.
Differences: found in plant cells but not in animal- chloroplasts, central
vacuole, tonoplast, cell wall, plasmodesmata; found in animal but not in
plant- lysosomes, centrioles, flagella. [animal cells are larger than plant
cells]
Why do unsaturated fatty acids help keep membranes more fluid at
lower temperatures? - ANSWER- If unsaturated fatty acids are
compressed, the "kinks" in their tails push adjacent phospholipid
molecules away, which helps maintain fluidity in the membrane.
What kinds of molecules pass through a cell membrane most easily? -
ANSWER- small hydrophobic molecules
