To analyze:
Why the evolution of multicellular organisms has led to the development of circulatory systems.
Introduction:
A circulatory system is responsible for transport of various substances through the body of the organism. There are various types of circulatory systems.

Explanation of Solution
Cells in a multicellular organism are not in direct contact with the external environment. This means that the exchange of gases, uptake of nutrients, expulsion of wastes and other such processes cannot be carried out in a simple, straightforward way. Simple diffusion, like in the case of unicellular organisms, is not enough to perform these functions. Dedicated delivery and waste removal systems became necessary. This is the reason for the development of the circulatory systems.
In multicellular organisms, most of the cells of an organism are not in direct contact with the external environment. Diffusion cannot adequately transport essential nutrients and wastes into and out of the cells. A dedicated delivery and removal system became necessary, and this led to the development of circulatory systems.
Want to see more full solutions like this?
Chapter 22 Solutions
WHAT IS LIFE? LAUNCHPAD 12 MO. SUB.
- You intend to insert patched dominant negative DNA into the left half of the neural tube of a chick. 1) Which side of the neural tube would you put the positive electrode to ensure that the DNA ends up on the left side? 2) What would be the internal (within the embryo) control for this experiment? 3) How can you be sure that the electroporation method itself is not impacting the embryo? 4) What would you do to ensure that the electroporation is working? How can you tell?arrow_forwardDescribe a method to document the diffusion path and gradient of Sonic Hedgehog through the chicken embryo. If modifying the protein, what is one thing you have to consider in regards to maintaining the protein’s function?arrow_forwardThe following table is from Kumar et. al. Highly Selective Dopamine D3 Receptor (DR) Antagonists and Partial Agonists Based on Eticlopride and the D3R Crystal Structure: New Leads for Opioid Dependence Treatment. J. Med Chem 2016.arrow_forward
- The following figure is from Caterina et al. The capsaicin receptor: a heat activated ion channel in the pain pathway. Nature, 1997. Black boxes indicate capsaicin, white circles indicate resinferatoxin. You are a chef in a fancy new science-themed restaurant. You have a recipe that calls for 1 teaspoon of resinferatoxin, but you feel uncomfortable serving foods with "toxins" in them. How much capsaicin could you substitute instead?arrow_forwardWhat protein is necessary for packaging acetylcholine into synaptic vesicles?arrow_forward1. Match each vocabulary term to its best descriptor A. affinity B. efficacy C. inert D. mimic E. how drugs move through body F. how drugs bind Kd Bmax Agonist Antagonist Pharmacokinetics Pharmacodynamicsarrow_forward
- 50 mg dose of a drug is given orally to a patient. The bioavailability of the drug is 0.2. What is the volume of distribution of the drug if the plasma concentration is 1 mg/L? Be sure to provide units.arrow_forwardDetermine Kd and Bmax from the following Scatchard plot. Make sure to include units.arrow_forwardChoose a catecholamine neurotransmitter and describe/draw the components of the synapse important for its signaling including synthesis, packaging into vesicles, receptors, transporters/degradative enzymes. Describe 2 drugs that can act on this system.arrow_forward
- The following figure is from Caterina et al. The capsaicin receptor: a heat activated ion channel in the pain pathway. Nature, 1997. Black boxes indicate capsaicin, white circles indicate resinferatoxin. a) Which has a higher potency? b) Which is has a higher efficacy? c) What is the approximate Kd of capsaicin in uM? (you can round to the nearest power of 10)arrow_forwardWhat is the rate-limiting-step for serotonin synthesis?arrow_forwardWhat enzyme is necessary for synthesis of all of the monoamines?arrow_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage LearningComprehensive Medical Assisting: Administrative a...NursingISBN:9781305964792Author:Wilburta Q. Lindh, Carol D. Tamparo, Barbara M. Dahl, Julie Morris, Cindy CorreaPublisher:Cengage LearningHuman Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning
- Basic Clinical Lab Competencies for Respiratory C...NursingISBN:9781285244662Author:WhitePublisher:CengageBiology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning



