Multiple choice

Which of the following components act as a circulatory fluid for sponges and hydras?

  1. Blood

  2. Air

  3. Water

  4. Plasma

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Animals such as sponges and hydras do not possess any circulatory system. The water in which they live acts as circulatory fluid for them. This is because it brings food and oxygen into their bodies.