Author Question: Planarians lack dedicated respiratory and circulatory systems because A) none of (Read 1117 times)

Charlie

  • Hero Member
  • *****
  • Posts: 640
Planarians lack dedicated respiratory and circulatory systems because
A) none of their cells are far removed from the gastrovascular cavity or from the external environment.
B) they lack mesoderm as embryos and, therefore, lack the adult tissues derived from mesoderm.
C) their flame bulbs can carry out respiratory and circulatory functions.
D) their body cavity, a pseudocoelom, carries out these functions.



camila

  • Hero Member
  • *****
  • Posts: 705
Answer has to be A, trust me!



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question

Charlie

  • Hero Member
  • *****
  • Posts: 640
Wonderful, you were right, thank you so much.



 

Did you know?

Tobacco depletes the body of vitamins A, C, and E, which can result in any of the following: dry hair, dry skin, dry eyes, poor growth, night blindness, abscesses, insomnia, fatigue, reproductive system problems, sinusitis, pneumonia, frequent respiratory problems, skin disorders, weight loss, rickets, osteomalacia, nervousness, muscle spasms, leg cramps, extremity numbness, bone malformations, decayed teeth, difficulty in walking, irritability, restlessness, profuse sweating, increased uric acid (gout), joint damage, damaged red blood cells, destruction of nerves, infertility, miscarriage, and many types of cancer.

Did you know?

Asthma attacks and symptoms usually get started by specific triggers (such as viruses, allergies, gases, and air particles). You should talk to your doctor about these triggers and find ways to avoid or get rid of them.

Did you know?

Your heart beats over 36 million times a year.

Did you know?

Approximately 500,000 babies are born each year in the United States to teenage mothers.

Did you know?

Certain rare plants containing cyanide include apricot pits and a type of potato called cassava. Fortunately, only chronic or massive ingestion of any of these plants can lead to serious poisoning.

For a complete list of videos, visit our video library