Zoology Exam 3 Questions with
Verified Answers
Describe the six different types of cells found in the epidermis of the hydra. - Answer-
1. Epitheliomuscular - cube shaped, most common, muscular contraction and
covering
2. Interstitial - undifferentiated cells, sex cells, everything
3. Gland cells - secrete mucus/enzymes
4.Cnidocytes
5.Sensory - sensory receptor for chemical/tactile stimuli
6.Nerve cells - conducting pulsation (stinging cells on tentacle)
Most cells in the dermis of a hydra have what shape? - Answer-Column shaped
Describe the three different types of cells found in the dermis of the hydra. - Answer-
1. Nutritive muscular cells
2. Gland Cells
3. Interstitial Cells
How does the mesoglea of the hydra differ from the mesoglea of the sponges? -
Answer-Hydra mesoglea lies between epidermis and gastrodermis
Gel like
Lacks fibers and cellular elements in hydrozoan polyp
Thicker medusa
Has elastic fibers
Sponge medusa has ameboid cells
Hydra medusa has epitheliomuscular cells
Describe the four different types of movements found in the hydra. - Answer-1. Hand
spring, head over tail
2. Inchworm movement - back drags forward then moves like worm
3. Basic disc gliding - secrete mucus at base to slide
4. Gas bubble - trap air gas in disc, release, float
What are the most common foods of the hydra? - Answer-Small crustaceans, water
fleas, aquatic worms, insect larva
How is the digestion in the hydra more advanced over the other organisms we have
discusses in the past? - Answer-Extracellular digestion - secrete digestive enzyme,
break it down, finish with intracellular digestion.
The presence of a gastrodermis and because extra and intracellular digestion
occurs; others feed by use of canal systems or pseudopodia.
How is the digestion in the hydra similar to the other organisms we have discussed
in the past? - Answer-Digestion is similar because they all engulf nutrition
Which of the cells found in the gastrodermis of the hydra complete digestion? -
Answer-Nutritive muscular
, Briefly describe the ways hydras reproduce.
Which of these types of reproduction more commonly occur during the winter? Why?
- Answer-Sexual - Male releases sperm into water, fertilize egg, form a cyst through
winter, synagamy
Asexual - budding a regeneration
Has polarity, can tell head from tail
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(hydrohiza) - Answer-water root; anchors root/colony to rock
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(hydrocauli) - Answer-Branches
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(coensarc) - Answer-Living tissue that interconnects all members of a colony.
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(perisarc) - Answer-Out covering chitenoeus.
Clear.
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(hydranth) - Answer-Feeding polyp.
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(gonangium) - Answer-Reproductive polyp.
What is the main function of the hydranth? - Answer-Capture and ingest prey
What is another name for the hydranth? - Answer-Mouth-feeding polyp.
What is the function of the gonangium? - Answer-Strictly asexual reproductive
polyps.
Be able to identify the following structures on the Gonionemus; exumbrella,
subumbrella, adhesive pads, velum, manubrium, radial canals, gonads and
statocyst. - Answer-
What is the function of the statocyst? - Answer-Specialized cell that keeps
equilibrium.
To which order and genus does the Portuguese man-of-war belong? - Answer-Order
Siphonophora
Genus pysalia
Verified Answers
Describe the six different types of cells found in the epidermis of the hydra. - Answer-
1. Epitheliomuscular - cube shaped, most common, muscular contraction and
covering
2. Interstitial - undifferentiated cells, sex cells, everything
3. Gland cells - secrete mucus/enzymes
4.Cnidocytes
5.Sensory - sensory receptor for chemical/tactile stimuli
6.Nerve cells - conducting pulsation (stinging cells on tentacle)
Most cells in the dermis of a hydra have what shape? - Answer-Column shaped
Describe the three different types of cells found in the dermis of the hydra. - Answer-
1. Nutritive muscular cells
2. Gland Cells
3. Interstitial Cells
How does the mesoglea of the hydra differ from the mesoglea of the sponges? -
Answer-Hydra mesoglea lies between epidermis and gastrodermis
Gel like
Lacks fibers and cellular elements in hydrozoan polyp
Thicker medusa
Has elastic fibers
Sponge medusa has ameboid cells
Hydra medusa has epitheliomuscular cells
Describe the four different types of movements found in the hydra. - Answer-1. Hand
spring, head over tail
2. Inchworm movement - back drags forward then moves like worm
3. Basic disc gliding - secrete mucus at base to slide
4. Gas bubble - trap air gas in disc, release, float
What are the most common foods of the hydra? - Answer-Small crustaceans, water
fleas, aquatic worms, insect larva
How is the digestion in the hydra more advanced over the other organisms we have
discusses in the past? - Answer-Extracellular digestion - secrete digestive enzyme,
break it down, finish with intracellular digestion.
The presence of a gastrodermis and because extra and intracellular digestion
occurs; others feed by use of canal systems or pseudopodia.
How is the digestion in the hydra similar to the other organisms we have discussed
in the past? - Answer-Digestion is similar because they all engulf nutrition
Which of the cells found in the gastrodermis of the hydra complete digestion? -
Answer-Nutritive muscular
, Briefly describe the ways hydras reproduce.
Which of these types of reproduction more commonly occur during the winter? Why?
- Answer-Sexual - Male releases sperm into water, fertilize egg, form a cyst through
winter, synagamy
Asexual - budding a regeneration
Has polarity, can tell head from tail
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(hydrohiza) - Answer-water root; anchors root/colony to rock
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(hydrocauli) - Answer-Branches
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(coensarc) - Answer-Living tissue that interconnects all members of a colony.
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(perisarc) - Answer-Out covering chitenoeus.
Clear.
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(hydranth) - Answer-Feeding polyp.
Be able to identify the following structures on the hydroid colony of an Obelia;
hydrorhiza, hydrocauli, coenosarc, perisarc, hydranth, hydratheca and gonangium.
(gonangium) - Answer-Reproductive polyp.
What is the main function of the hydranth? - Answer-Capture and ingest prey
What is another name for the hydranth? - Answer-Mouth-feeding polyp.
What is the function of the gonangium? - Answer-Strictly asexual reproductive
polyps.
Be able to identify the following structures on the Gonionemus; exumbrella,
subumbrella, adhesive pads, velum, manubrium, radial canals, gonads and
statocyst. - Answer-
What is the function of the statocyst? - Answer-Specialized cell that keeps
equilibrium.
To which order and genus does the Portuguese man-of-war belong? - Answer-Order
Siphonophora
Genus pysalia
