Question

porifera station lab**
name
station #7: comparison

1. how does a sponge function compared to a protist? complete the table below to compare the two categories of organism. be specific and give details from class notes!!!

respiration

porifera

protist

|digestion|
|reproduction|
|excretion|

Explanation:

• Respiration: Porifera (sponges) exchange gases through diffusion across their cell - membranes as water flows through their pores. Protists can also use diffusion for gas - exchange, but some have specialized structures like contractile vacuoles for osmoregulation which can be related to their respiration in an aquatic environment.
• Digestion: Sponges have intracellular digestion where food particles are engulfed by choanocytes and digested within the cells. Many protists also perform intracellular digestion, but some like certain ciliates have a more complex feeding groove or oral apparatus for taking in food.
• Reproduction: Porifera can reproduce asexually by budding or fragmentation and sexually through the release of gametes. Protists can reproduce asexually by binary fission, multiple fission, or budding, and sexually through conjugation in some species.
• Excretion: In sponges, waste products are removed by diffusion as water passes through the sponge. Protists excrete waste either by diffusion across the cell membrane or through specialized organelles like contractile vacuoles that help in osmoregulation and also expel some metabolic wastes.

Answer:

Respiration	Porifera	Protist
Digestion	Intracellular digestion by choanocytes.	Intracellular digestion; some have specialized feeding structures.
Reproduction	Asexual (budding, fragmentation) and sexual (gamete release).	Asexual (binary fission, multiple fission, budding) and sexual (conjugation in some).
Excretion	Waste removal by diffusion as water passes through.	Waste removal by diffusion or through specialized organelles like contractile vacuoles.