Growth factors
a. are adhesion substances
b. inhibit the cell cycle
c. can cause neoplasms
d. invite transcription of growth genes
e. are nucleic acids
is it b?
To determine the correct answer, let's go through the options one by one:
a. Adhesion substances: Growth factors are not primarily adhesion substances. They are signaling molecules that promote cell division, differentiation, and survival.
b. Inhibit the cell cycle: This statement is incorrect. Growth factors generally stimulate or promote cell cycle progression, rather than inhibiting it.
c. Can cause neoplasms: Growth factors themselves do not directly cause neoplasms, which are abnormal and uncontrolled growths of cells. However, excessive or abnormal activation of growth factors and their receptors can contribute to the development of neoplasms.
d. Invite transcription of growth genes: This statement is partially correct. Growth factors generally bind to specific receptors on the cell surface, which triggers a signaling cascade that can lead to the activation of various genes, including growth-related genes.
e. Are nucleic acids: Growth factors are not nucleic acids. They are proteins or peptides that act as signaling molecules.
Based on the explanations above, the correct answer is not option b but rather option d: Growth factors induce the transcription of growth genes.