cell signaling

idk

G1 to G2 DNA content change?

+100%

Quorum sensing question?

Did these species evolve from a common ancestor that used a similar signaling molecule?

brain and rib cage, response to increase in cellular respiration in body?

In response to low blood pH, the pH sensors send a signal to the brain, which then sends a signal to the diaphragm, resulting in an increased rate of breathing to help eliminate excess blood CO2

least likely to result in initiation of a cancerous tumor?

A defect in a cell cycle checkpoint prevents a cell from entering the S phase

Ferritin and iron question, figure 2?

Translation occurs under high intracellular iron concentration when the IRP-iron complex disassociates from ferritin mRNA, permitting ribosomes access to the ferritin coding region

best evidence that Acetyl-CoA negatively regulates pruvate dyhydrogense activity?

The rate of the pyruvate dehydrongase-catalyzed reaction is slower in the presence of a higher concentration of Acetyl-CoA.

Ethylene gas is an organic molecule that serves many cell signaling roles in flowering pants. ethylene positive feedback mechanism?

Cells of ripening fruits produce ethylene, which activates the ripening response in other fruit cells.

The endocrine system incorporates feedback mechanisms that maintain homeostasis. Which demonstrates negative feedback?

After a meal, blood glucose levels become elevated, stimulating beta cells of the pancreas to release insulin into the blood. Excess glucose is then converted to glycogen in the liver, reducing blood glucose levels.

EGF is a protein that stimulates cell division and growth by binding to its receptor HER2. Certain cancer is caused when EGP activates a cell-signaling pathway, leading to uncontrolled cell division. how can tumor growth be inhibited?

a drug binds to HER2, preventing activation of the signaling pathway

How does the amount of DNA in the cell change during M phase?

The amount of DNA is halved as the cell divides into 2 daughter cells

The graph with Melanocytes and drug X, figure 1

At a concentration above 10 micrometers, drug X reduces melanoma cell survival

Which of the following statements about the activity of platelets best explains a positive feedback mechanism.

Activated platelets release chemicals that activate more platelets.

Which of the following best explains the most likely method by which this antitumor drug works?

Trabectidin interferes with the duplication of DNA during interphase and thus prevents cancer cells from passing the G2 checkpoint.

The drug 5-fluorouracil inhibits thymine production in eukaryotic cells. Which of the following cell cycle stages will be most directly affected by it?

Synthesis of DNA phase (S)

Which of the following best explains how exercise causes blood glucose levels to rise?

Epinephrine activates alpha cells, causing glucagon release, inhibits beta cells, blocking insulin release.

which of the following describes a cell in which cell cycle progression continues?

A cell in which only enzyme 1 is function, 2 and 3 are nonfunctional

Exposed to radiation, which supports researchers claim that radiation doesn’t allow cell cycle progression

Experimental group were not able to enter G2 phase

The BIG BIG BIG photosynthesis 2SE +- question

A negative feedback mechanism that reverses the environmental change

Which of the following best describes a cell that is in the G1 stage of the cell cycle

The cell is growing in size and increasing proteins / organelle amount

what role does ADH play in maintaining blood osmolarity?

ADH promotes an increase in the movement of water into the bloodstream

GnRH, which observation provides evidence of a positive feedback mechanism?

Estrogen from ovaries stimulates hypothalamus and anterior pituitary to secrete more GnRH, LH, and FSH.

Which of the following best explains the role of cell-to-cell communication during a response to an invasion of antigens

Chemicals that are secreted from antigen-presenting cells then activate helper T cells

The two loops

Calcitonin levels will rise, promoting the deposit of calcium into bones.

CDK 7 and MAT 1 - 3 protein complex

Increased expression of CDK 7 is associated with cancer

cortisol - what happens after starvation and increase in cortisol secretion?

Increased mobilization of fatty acids from fat cells.