Types of Signaling
What are the 3 ways cells communicate?
direct contact, local signaling, long-distance signaling
What are the 3 steps in the signal transduction pathway?
Reception, transduction, and response
Why is homeostasis often described as balance?
It maintains stable internal conditions within a narrow range
What happens during cytokinesis?
Cytoplasm is divides to form two genetically identical daughter cells
How many checkpoints are involved in the regulation of the cell cycle?
3
What is the protein that organizes chromosomes and around which DNA wraps?
Histone
What type of junction allows animal cells to communicate directly?
Gap junctions
What is the molecule called that binds to a receptor to start a signaling pathway?
Ligand
What type of feedback returns a system to its set point?
Negative Feedback
During which stage of the cell cycle does DNA replicate? Be specific.
S stage (interphase)
What checkpoint decided whether or not the cell will undergo division or enter the G0 phase?
G1 checkpoint
What is apoptosis?
Controlled cell death
Plant cells communicate directly using what structures?
Plasmodesmata
Where are receptors for water-soluble (polar) ligands found?
On the cell membrane
What type of feedback amplifies a response, such as during childbirth?
Positive Feedback
At what point in the cell cycle do the sister chromatids separate?
Anaphase
At what checkpoint does the cell check to see if the spindle fibers are attached correctly?
M checkpoint
A diploid organism with a total of 22 chromosomes has an n of...
11
This type of signaling involves local regulators affecting nearby target cells.
Paracrine signaling
What are the enzymes that transfer phosphate groups from ATP to a protein?
protein kinase
Explain how negative feedback helps regulate blood glucose levels.
High glucose triggers insulin release, lowering glucose back to normal
Two new nuclei form during this stage of Mitosis?
Telophase
What molecules regulate progression through the cell cycle?
Cyclins and cyclin-dependent kinases (CDKs)
One half of a duplicated chromosome is a ____________
Chromatid
Why is synaptic signaling considered a form of local signaling?
Neurotransmitters travel a very short distance across the synapse
What is the primary function of second messengers like cAMP?
To relay and amplify the signal inside the cell
Predict what would happen to homeostasis if negative feedback mechanisms failed.
Internal conditions would become unstable, potentially leading to disease or death
What are the 3 steps of interphase and 5 steps of mitosis in order?
G1, S, G2, prophase, prometaphase, metaphase, anaphase, telophase/cytokinesis
What causes cancer?
The accumulation of mutations/ errors in genetic material.
OR
Uncontrolled cell growth.
A diploid organism with n=5 would have this many chromatids in metaphase
20