Porifera

 

Unless otherwise stated, you are responsible for recognizing each prepared slide and parts if indicated.  Because slide quality varies, I suggest you study more than one of each slide.  On the slides:  c.s.” or “x.s.” means cross section (also called transverse section), “l.s.” means longitudinal section, and “w.m.” means whole mount.  A (D) after a slide name means that slide will be on demonstration; (FYI) means you may find it interesting, but you don't have to sketch it in your lab notebook..  Be able to recognize macroscopic specimens (including those on demonstration), plus any listed parts.  The information and/or taxonomy for each specimen that is discussed in lecture may also be covered on the lab exams. 

 

 “L” = lab manual; “T” = text; “R” Rust lab manual (the Rust manual will be available in lab)

numbers following “L”, “T” and “R” refer to page numbers

 

poriferans:

Overview L29

(Grantia = Sycon = Scypha)

Grantia l.s. & c.s.L31 Figs 4.5-4.8; R50-52 pinacocyte cells (epidermis), ostium, osculum, incurrent canal, choanocytes, mesohyl, radial canal, spongocoel

spongin (D) R52

spicules L31 Fig 4.9; T79 Fig 4.1 & 4.2; R52

bath sponge L32 Fig 4.10

gemmules T80 Fig 4.3

 

 

Please answer the following questions in your lab notebook:

 

1) Strong support for monophyly of the animal kingdom comes from all of the following except one. Which is the exception?

a. the presence of flagellated cells in all animals

b. the presence of asters used in cell division in all animals

c. the presence of bilateral symmetry in all animals

d. molecular data

 

2) Why are choanoflagellates considered to be the closest living relatives of animals?

 

 

 

 

3) _____________ are cells that set up currents creating water flow through the sponge. Water flows into the sponge body through numerous pores on the outer surface called _______, and then along canals passing through openings in specialized cells called ___________. Finally the water flows into the ____________, a large central chamber in most sponges, and is released from the sponge through the ____________.

 

4) How do sponges reproduce? What are gemmules?

 

 

 

 

5) What cell type in sponges is responsible for distributing food to other cells? Are there other roles that these cells perform?

 



6) What is the advantage of a highly convoluted body wall in sponges? List the three sponge body plans from least to most complex.

 

 

 

7) Colonies are defined as "loose associations of independent cells". Why are sponges considered to have surpassed that level of organization?