Which of the following nitrogenous waste requires hardly any water for its excretion

Which of the following structures contains nitrogen waste excreted with the digestive system?

What structure is involved in absorbing nutrients in the grasshopper

When is urine concentrated?  

The ____________ is responsible for closing off the airway during swallowing.  

This structure brings deoxygenated blood back from the lower part of the body

Which side of the heart has oxygenated blood and is considered to have systemic blood flow?

The actual gas exchange in the lungs occurs in the

The tricuspid valve is found on which side of the heart?

Which of the following represents a correct sequence?