
Concept explainers
Paracrine signaling is characterized by ligands that are
a. produced by the cell itself.
b. secreted by neighboring cells.
c. present on the plasma membrane of neighboring cells.
d. secreted by distant cells.

Introduction:
Cells can communicate with each other by various mechanisms such as direct contact, paracrine signaling, endocrine signaling and synaptic signaling.
Answer to Problem 1U
Correct answer:
Paracrine signaling is characterized by the ligands that are secreted by neighboring cells. Therefore, option b. is correct.
Explanation of Solution
Reason for the correct statement:
The paracrine signaling is a type of cell-cell communication in which a cell produces signaling molecules (ligands) that diffuse through the extracellular matrix to affect cells present in the nearby areas.
Option b. is given as “secreted by neighboring cells”.
As “paracrine signaling involves secretion of ligands by the neighboring cells”, is the right answer.
Hence, option b. is correct.
Reason for the incorrect statements:
Option a. is given as “produced by the cells itself”.
In autocrine signaling, the ligands produced by a cell bind to its own receptor. So, it is a wrong answer.
Option c. is given as “present on the plasma membrane of neighboring cells”.
In direct signaling, the ligand present on a cell bind to a receptor present on the plasma membrane of a neighboring cell. So, it is a wrong answer.
Option d. is given as “secreted by distant cells”.
In endocrine signaling, a cell produces ligands that enter the circulatory system to act on the distant target cells. So, it is a wrong answer.
Hence, options a., c, and d. are incorrect.
Paracrine signaling involves secretion of ligands that acts on the target cells present in the neighboring areas.
Want to see more full solutions like this?
Chapter 9 Solutions
Biology
- Using quail and chick embryos, quail-specific antibody and fluorescent tissue-specific antibodies, design an experiment where you investigate the tissues the cranial neural crest can give rise to. What are four derivatives of the cranial neural crest that you expect to see in the resulting chimeric embryos?arrow_forwardDoes the neural crest have to undergo epithelial to mesenchymal transition prior to migration through the developing embryo? Does the neural crest differentiate into different cell types based on their axial position along the anterior and posterior axis?arrow_forwardUsing quail and chicken embryos, what kind of experiment would you conduct to test if rib forming somites have their axial identity specified before segmentation? How do we know this phenotype is due to axial identity being specified before segmentation and not due to our experimental method?arrow_forward
- 8. Aerobic respiration of a 5 mM solution of tripeptide that is composed of the following three amino acids; alanine, leucine and isoleucine. Alanine breaks down to pyruvate, leucine breaks down to Acetyl-CoA and isoleucine breaks down to succinyl-CoA. Alanine NADH FADH2 OP ATP SLP ATP Total ATP Leucine Isoleucine Totals Show your work using dimensional analysis here: 4arrow_forward9. Aerobic respiration of one lipid molecule. The lipid is composed of one glycerol molecule connected to two fatty acid tails. One fatty acid is 12 carbons long and the other fatty acid is 18 carbons long in the figure below. Use the information below to determine how much ATP will be produced from the glycerol part of the lipid. Then, in part B, determine how much ATP is produced from the 2 fatty acids of the lipid. Finally put the NADH and ATP yields together from the glycerol and fatty acids (part A and B) to determine your total number of ATP produced per lipid. Assume no other carbon source is available. fatty acids glycerol 18 carbons 12 carbons 0=arrow_forwardinfluences of environment on the phenotype.arrow_forward
- What is the difference between codominance and phenotypic plasticity?arrow_forwardExplain the differences between polygeny and pleiotropy,arrow_forwardIf using animals in medical experiments could save human lives, is it ethical to do so? In your answer, apply at least one ethical theory in support of your position.arrow_forward
- You aim to test the hypothesis that the Tbx4 and Tbx5 genes inhibit each other's expression during limb development. With access to chicken embryos and viruses capable of overexpressing Tbx4 and Tbx5, describe an experiment to investigate whether these genes suppress each other's expression in the limb buds. What results would you expect if they do repress each other? What results would you expect if they do not repress each other?arrow_forwardYou decide to delete Fgf4 and Fgf8 specifically in the limb bud. Explain why you would not knock out these genes in the entire embryo instead.arrow_forwardYou implant an FGF10-coated bead into the anterior flank of a chicken embryo, directly below the level of the wing bud. What is the phenotype of the resulting ectopic limb? Briefly describe the expected expression domains of 1) Shh, 2) Tbx4, and 3) Tbx5 in the resulting ectopic limb bud.arrow_forward
- Biology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage LearningHuman Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage LearningBiology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning
- Human Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning



