Unit 4 AP Biology Review

How do cancer cells differ from normal cells in terms of cell cycle regulation?

• Cancer cells have faster cell cycle progression than normal cells.

• Cancer cells have identical cell cycle regulation to normal cells.

• Cancer cells have dysregulated cell cycle control due to mutations in cell cycle regulatory genes.

• Cancer cells have more checkpoints in the cell cycle than normal cells.

Tags

NGSS.HS-LS3-2

What is the main function of second messengers in cell signaling?

• To amplify the signal received by the receptor

• To deactivate the signaling pathway

• To act as the primary signal molecule

• To directly alter gene expression

In the context of signal transduction, what is a kinase?

• An enzyme that adds phosphate groups to proteins

• A molecule that binds to DNA to initiate transcription

• A type of receptor on the cell surface

• A second messenger molecule

How do steroid hormones transmit their signal inside a cell?

• By binding to surface receptors and activating second messengers

• By entering the cell and directly binding to intracellular receptors

• By activating G proteins on the cell surface

• By phosphorylating membrane proteins

Plant cells can exchange small soluble compounds with neighboring cells directly through junctions in the cell wall called -

• gap junctions

• thylakoids

• stomata

• plasmodesmata

A mutation in a cell membrane receptor would most likely have what effect on a signal transduction pathway?

• Reduce the response of the pathway

• An alternative response will be expressed

• Increase ligand binding

• Increase ligand release from the effector cell

This diagram shows transduction of a signal. How is the signal being transduced to its target location in the cell?

• A hormone is binding to an intracellular protein receptor

• Transport vesicles are passing neurotransmitters to neighboring cells

• Enzymes are passing phosphate groups down a series of proteins

• cAMP is formed activating a desired response

Why do mutations in receptor proteins affect cell signaling?

• The receptor needs the proper sequence of amino acids to interact with the cell membrane

• The receptor needs a specific shape to bind to it's ligand

• The receptor must have the right polarity to interact with it's ligand

• All of the above

Tags

NGSS.HS-LS3-2

If a medicine works by blocking a secondary messenger, what effect would it have on that cell signaling pathway?

• It would increase the response if the pathway

• It would trigger the release of more ligands

• It would activate the transcription of a desired gene

• It would inhibit transduction, thus deactivating the response

What important event happens during the S-phase of the cell cycle?

• The mitotic spindle forms

• The nuclear membrane breaks down

• DNA replication

• Sister chromatids separate