BIOS 255 UNIT 4 MIDTERM EXAM
COMPREHENSIVE STUDY GUIDE 2026
◉ What are the three general ways cells communicate? Answer:
Direct contact, local signaling, and long-distance signaling.
◉ What is direct contact in cell communication? Answer:
Communication through cell junctions where signaling substances
can pass freely between adjacent cells.
◉ What structures allow animal cells to communicate through direct
contact? Answer: Gap junctions.
◉ What structures allow plant cells to communicate through direct
contact? Answer: Plasmodesmata.
◉ Give an example of direct contact communication. Answer:
Immune cells (APCs) communicate with T cells through direct
contact.
◉ What are local regulators in cell signaling? Answer: Chemical
messages released by a secreting cell that travel a short distance to
cause a response in a target cell.
, ◉ What is paracrine signaling? Answer: A type of local signaling
where secretory cells release local regulators to adjacent cells.
◉ Provide an example of paracrine signaling. Answer: Nitric oxide
relaxing smooth muscle when heart rate increases.
◉ What is synaptic signaling? Answer: A type of local signaling in
the nervous system where neurons secrete neurotransmitters into
the synaptic cleft.
◉ What is long-distance signaling in animals? Answer: The use of
hormones released into the circulatory system to reach target cells.
◉ How do plants perform long-distance signaling? Answer: By
releasing hormones that travel through vascular tissue or through
the air.
◉ What is insulin signaling? Answer: Insulin is released by the
pancreas into the bloodstream to bind to target cells.
◉ What are the three stages of cell signaling? Answer: Reception,
transduction, and response.
COMPREHENSIVE STUDY GUIDE 2026
◉ What are the three general ways cells communicate? Answer:
Direct contact, local signaling, and long-distance signaling.
◉ What is direct contact in cell communication? Answer:
Communication through cell junctions where signaling substances
can pass freely between adjacent cells.
◉ What structures allow animal cells to communicate through direct
contact? Answer: Gap junctions.
◉ What structures allow plant cells to communicate through direct
contact? Answer: Plasmodesmata.
◉ Give an example of direct contact communication. Answer:
Immune cells (APCs) communicate with T cells through direct
contact.
◉ What are local regulators in cell signaling? Answer: Chemical
messages released by a secreting cell that travel a short distance to
cause a response in a target cell.
, ◉ What is paracrine signaling? Answer: A type of local signaling
where secretory cells release local regulators to adjacent cells.
◉ Provide an example of paracrine signaling. Answer: Nitric oxide
relaxing smooth muscle when heart rate increases.
◉ What is synaptic signaling? Answer: A type of local signaling in
the nervous system where neurons secrete neurotransmitters into
the synaptic cleft.
◉ What is long-distance signaling in animals? Answer: The use of
hormones released into the circulatory system to reach target cells.
◉ How do plants perform long-distance signaling? Answer: By
releasing hormones that travel through vascular tissue or through
the air.
◉ What is insulin signaling? Answer: Insulin is released by the
pancreas into the bloodstream to bind to target cells.
◉ What are the three stages of cell signaling? Answer: Reception,
transduction, and response.
