A+
AP Bio Unit 4 2025/2026 Exam Questions
Marking Scheme New Update | A+ Rated
Chemicals that are secreted from antigen-presenting cells then activate helper T
cells. - 🧠 ANSWER ✔✔An antigen can induce an immune response in a host
organism. Antigens are targeted by antibodies that are produced by the organism's
immune system in response to contact with the antigen. Antibodies are specific to
antigens. Many different cell types are involved in immune responses.
Which of the following best describes the role of cell-to-cell communication
during a response to an invasion of antigens?
They allow the movement of molecules from one cell to another, enabling
communication between cells. - 🧠 ANSWER ✔✔Adjacent plant cells have narrow
channels called plasmodesmata that pass through the cell walls of the connected
cells and allow a cytoplasmic connection between the cells.
Which of the following statements best describes a primary function of
plasmodesmata?
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, A+
The hormone is released into the bloodstream where it can be transported to all
cells with the correct receptors. - 🧠 ANSWER ✔✔A hydrophilic peptide hormone
is produced in the anterior pituitary gland located at the base of the brain. The
hormone targets specific cells in many parts of the body.
Which of the following best explains a possible mechanism that would enable the
hormone to efficiently reach all of the target cells in the body?
cAMP results in the activation of an enzyme that amplifies the signal by acting on
many substrate molecules. - 🧠 ANSWER ✔✔G proteins are a family of receptor
proteins that are involved in transmitting signals from outside a cell to inside a cell.
When a signaling molecule binds to a G protein, the G protein is activated. The G
protein then activates an enzyme that produces a second messenger called cAMP.
Which of the following describes a critical role of cAMP during the transduction
stage of a G protein signal transduction pathway?
it is a ligand that activates the signal transduction pathway of the activation of
AMPK. - 🧠 ANSWER ✔✔Metformin is a drug used to treat type 2 diabetes by
decreasing glucose production in the liver. AMP-activated protein kinase (AMPK)
is a major cellular regulator of glucose metabolism. Metformin activates AMPK in
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, A+
liver cells but cannot cross the plasma membrane. By blocking AMPK with an
inhibitor, researchers found that AMPK activation is required for metformin to
produce an inhibitory effect on glucose production by liver cells.
Which of the following best describes the component that metformin represents in
a signal transduction pathway that regulates glucose production in the liver?
A ligand binds to a receptor. - 🧠 ANSWER ✔✔Which of the following steps in a
signaling pathway typically occurs first once a chemical messenger reaches a target
cell?
Cell signaling depends on the ability to detect a signal molecule. Not all cells have
receptors for epinephrine. Only cells with such receptors are capable of
responding. - 🧠 ANSWER ✔✔During a fight-or-flight response, epinephrine is
released into the body's circulatory system and transported throughout the body.
Some cells exhibit a response to the epinephrine while other cells do not.
Which of the following justifies the claim that differences in components of cell
signaling pathways explain the different responses to epinephrine?
If the SRY gene is absent or nonfunctional, the embryo will exhibit female sexual
development. - 🧠 ANSWER ✔✔Signal transduction may result in changes in gene
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
AP Bio Unit 4 2025/2026 Exam Questions
Marking Scheme New Update | A+ Rated
Chemicals that are secreted from antigen-presenting cells then activate helper T
cells. - 🧠 ANSWER ✔✔An antigen can induce an immune response in a host
organism. Antigens are targeted by antibodies that are produced by the organism's
immune system in response to contact with the antigen. Antibodies are specific to
antigens. Many different cell types are involved in immune responses.
Which of the following best describes the role of cell-to-cell communication
during a response to an invasion of antigens?
They allow the movement of molecules from one cell to another, enabling
communication between cells. - 🧠 ANSWER ✔✔Adjacent plant cells have narrow
channels called plasmodesmata that pass through the cell walls of the connected
cells and allow a cytoplasmic connection between the cells.
Which of the following statements best describes a primary function of
plasmodesmata?
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, A+
The hormone is released into the bloodstream where it can be transported to all
cells with the correct receptors. - 🧠 ANSWER ✔✔A hydrophilic peptide hormone
is produced in the anterior pituitary gland located at the base of the brain. The
hormone targets specific cells in many parts of the body.
Which of the following best explains a possible mechanism that would enable the
hormone to efficiently reach all of the target cells in the body?
cAMP results in the activation of an enzyme that amplifies the signal by acting on
many substrate molecules. - 🧠 ANSWER ✔✔G proteins are a family of receptor
proteins that are involved in transmitting signals from outside a cell to inside a cell.
When a signaling molecule binds to a G protein, the G protein is activated. The G
protein then activates an enzyme that produces a second messenger called cAMP.
Which of the following describes a critical role of cAMP during the transduction
stage of a G protein signal transduction pathway?
it is a ligand that activates the signal transduction pathway of the activation of
AMPK. - 🧠 ANSWER ✔✔Metformin is a drug used to treat type 2 diabetes by
decreasing glucose production in the liver. AMP-activated protein kinase (AMPK)
is a major cellular regulator of glucose metabolism. Metformin activates AMPK in
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
, A+
liver cells but cannot cross the plasma membrane. By blocking AMPK with an
inhibitor, researchers found that AMPK activation is required for metformin to
produce an inhibitory effect on glucose production by liver cells.
Which of the following best describes the component that metformin represents in
a signal transduction pathway that regulates glucose production in the liver?
A ligand binds to a receptor. - 🧠 ANSWER ✔✔Which of the following steps in a
signaling pathway typically occurs first once a chemical messenger reaches a target
cell?
Cell signaling depends on the ability to detect a signal molecule. Not all cells have
receptors for epinephrine. Only cells with such receptors are capable of
responding. - 🧠 ANSWER ✔✔During a fight-or-flight response, epinephrine is
released into the body's circulatory system and transported throughout the body.
Some cells exhibit a response to the epinephrine while other cells do not.
Which of the following justifies the claim that differences in components of cell
signaling pathways explain the different responses to epinephrine?
If the SRY gene is absent or nonfunctional, the embryo will exhibit female sexual
development. - 🧠 ANSWER ✔✔Signal transduction may result in changes in gene
COPYRIGHT©PROFFKERRYMARTIN 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE.
PRIVACY STATEMENT. ALL RIGHTS RESERVED
