Question

In most of the Aschelminthes, the respiratory and circulatory systems are absent. Where do they get their oxygen needed for their metabolism?

• A. They can absorb oxygen directly from air.
• B. They have special oxygen cylinder attached to them.
• C. They have an air bubble which feeds them.
• D. They obtain oxygen from their host through their body wall.

Answer 1

The correct option is D They obtain oxygen from their host through their body wall.

• The roundworms belong to the group of Aschelminthes.
• These worms do not have a developed respiratory which can allow the oxygen to enter and circulatory system which can help in the distribution of the oxygen to the different cells.
• The body wall is thin and allows the oxygen to get diffused in the cells and this allows the organisms to perform the metabolic reactions.
• Thus, the correct answer is option D.