Answer:
chloroplast i think , i may b wrong
Answer: D
Explanation: Oxygen plays a vital role in energy production via a system called electron transport chain , which is an important component of cellular respiration. ... Oxygen acts as a final electron acceptor that helps move electrons down a chain that results in adenosine triphosphate production
Answer: Water is polluted
Explanation: Im so sorry if this is wrong btw but im pretty sure its right
Answer:
Option D, has only a single opening
Explanation:
A gastrovascular cavity has only one opening. The food goes in and comes out of the same opening there by making it a two way digestive tract.
However, a digestive tube is a one way digestive tract where the food goes in from mouth (one end) and comes out of anus (second end) . It is also called as alimentary canal
Hence, option D is correct