
Concept introduction: Cell proliferation is a process of increasing the cell number to create a balance between the cell divisions and cell loss. Abnormal proliferation of cells leads to the formation of tumors and cancers. Proliferation process is controlled using positive and negative regulators present in the cell.

Answer to Problem 1SQ
Correct answer:
Transforming growth factor beta (TGF-β), which blocks the cell cycle when there is DNA damage, is an example of a negative growth regulator.
Therefore, option d. is the correct answer.
Explanation of Solution
Reasons for the correct statement:
Positive regulators of the cell initiate the cell to divide, proliferate, and survive. However, the negative regulators are required for a cell to stop the cell division and activate the abnormal cell to undergo programmed cell death.
Option d. is given as “Transforming growth factor beta (TGF-β), which blocks the cell cycle when there is DNA damage”. TGF- β is a cytokine molecule which helps the cells to proliferate, differentiate, adhesion, and apoptosis. They act as mediator molecules to stop the cell cycle when DNA undergoes damage.
Hence, option d. is the correct answer.
Reasons for the incorrect statements:
Option a. is given as “human growth hormone, which stimulates cell division in bone”. This is incorrect because it does not have a negative growth regulator activity. Therefore, option a. is incorrect.
Option b. is given as “human growth hormone receptor, which is part of the signal transduction pathway for the hormone”. This receptor can only activate the signal transduction pathway, but it cannot inhibit the growth of cell. Therefore, option b. is incorrect.
Option c. is given as “prostate-specific antigen, which is a tumor maker found on the surface of prostate cancer cells.” This is not a negative regulator of cell, but it induces the cancer development. Therefore, option c. is incorrect.
Hence, options a., b., and c. are incorrect.
Want to see more full solutions like this?
Chapter 8 Solutions
EBK DISCOVER BIOLOGY (CORE SIXTH EDITIO
- What is behavioral adaptarrow_forward22. Which of the following mutant proteins is expected to have a dominant negative effect when over- expressed in normal cells? a. mutant PI3-kinase that lacks the SH2 domain but retains the kinase function b. mutant Grb2 protein that cannot bind to RTK c. mutant RTK that lacks the extracellular domain d. mutant PDK that has the PH domain but lost the kinase function e. all of the abovearrow_forwardWhat is the label ?arrow_forward
- Can you described the image? Can you explain the question as well their answer and how to get to an answer to an problem like this?arrow_forwardglg 112 mid unit assignment Identifying melting processesarrow_forwardGive only the mode of inheritance consistent with all three pedigrees and only two reasons that support this, nothing more, (it shouldn't take too long)arrow_forward
- Oarrow_forwardDescribe the principle of homeostasis.arrow_forwardExplain how the hormones of the glands listed below travel around the body to target organs and tissues : Pituitary gland Hypothalamus Thyroid Parathyroid Adrenal Pineal Pancreas(islets of langerhans) Gonads (testes and ovaries) Placentaarrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education





