Sponges lack __________.

• A. a complete digestive tract
• B. a nervous system
• C. the ability to make organic compounds from CO₂ and water
• D. tissues
• E. All of the listed responses are correct.

Answer: (E)

Verified step by step guidance

1. Understand the basic biology of sponges: Sponges are simple multicellular organisms that belong to the phylum Porifera. They are considered one of the most primitive forms of animal life.
2. Identify the characteristics of sponges: Sponges lack true tissues and organs, which distinguishes them from more complex animals. They have a porous body and a simple organization.
3. Examine the digestive system of sponges: Sponges do not have a complete digestive tract. Instead, they filter feed by drawing water through their pores and extracting nutrients from it.
4. Consider the nervous system: Sponges lack a nervous system. They do not have nerve cells or a brain, which means they cannot respond to stimuli in the same way as more complex animals.
5. Evaluate the ability to synthesize organic compounds: Sponges cannot make organic compounds from CO2 and water through photosynthesis, as they are not autotrophic organisms. They rely on filtering organic particles from the water.