Questions on Phylum Porifera
1st Question: Choose the correct answer
1. Poriferan species are
a) epifaunal sedentary        b) infaunal sedentary                        c) vagile
2. Poriferans are
a) Aquatic                              b) Marine                                              c) Aquatic mostly marine
3. Mode of life of porifera is
a) Plankton                           b) Benthonic                                         c) Nekton
4. Most skeletons in porifera  are:
a) Exoskeletons                   b) Endoskeletons                                c) Without skeletons
5. Hard skeletons in porifera consist of:
a) Silica                                  b) Ca Co3            c) Spogine             d) All are possible
6. Porifera that composed of silica spicules are abundant in:        
a) Deep water       b) Shallow water                 c) Both together                   C) No relation
7. The outer layer of sponges                 
a) Pinacocytes                       b) Choanocytes                                 c) Mesenchyme
8. The inner layer of sponge
a) Pinacocytes                       b) Choanocytes                                 c) Mesenchyme
9. The gelatinous middle layer of sponge
a) Pinacocytes                      b) Choanocytes                                   c) Mesenchyme
10. Calcareous sponges are abundant in:            
a) Deep water       b) Shallow water                 c) Both together      C) No relation
 
2nd Question: Give the scientific term

1. The simplest structural grade of sponge.
2. The complex structure grade of sponge.
3. The middle layer between the pinacocyte and choanocyte layers.
4. Large excurrent pore through which water go out the sponge.
5. Pores through which water enter the sponge.
6. The intermediate structure grade of sponge.

 
3rd Question: Complete

1. Calcareous sponges increase in…………….…..environment.
2. Siliceous sponges increase in…………………..environment.
3. The three modes of sponge structures are …….…...,………..….and….……….
4. Sponge spicules composed of one or more of the following components……………..….,………………….….,……………..…
5. The basis of classification of porifera are…………………….,…………….……
6. Water enters sponges through small pores called ………….. and exits through larger one called…………………
7. ……………………….is the outer layer of sponge.
8. …………………..…..is the inner layer of sponge.
9. …………………..….is the gelatinous middle layer of sponge.
10. The functions of pinacocytes are………………….…..and…………………..…...
11. The functions of choanocytes are……………………...and………………………...
12. The function of Sclerocytes and spongocytes is…………………………………
13. Nomenclature of sponge spicules depend on……………………….and ……….….…
14. The most environmental factors affecting the distribution and abundance of sponges are…………….…,…………………… and…………………….…

 
4th Question: Justify

1. Most sponges live in quiet and clear waters.
2. Fossil record of porifera is poor.

 
5th Question: Write the skeleton grade