The phylum Echinodermata has several synapomorphies, but each subgroup modifies these synapomorphies and thus it is...

The phylum Echinodermata has several synapomorphies, but each subgroup modifies these synapomorphies and thus it is difficult to relate these groups.

a) List three synapomorphies for the phylum Echinodermata.

b) For each of the synapomorphies you list, how do you expect those features to differ between the asteroids and holothuroids?

c) For the phylum Echinodermata, which class do you think is most similar? Why?

d) What phyla were the Echinodermata historically confused with, and why? Which do they most relate to and how is this known?

Solutions

Expert Solution

Solution:

A) The echinoderm or spiny-skinned animals represent a group of marine invertebrates.

The important synapomorphies exhibited by echinoderms are 1) Radial symmetry, 2) Presence of calcium rich ossicle plates and 3) Well developed and unique water vascular system. These ar the important three synapomorphies for the phylum Echinodermata.

B) The asteroids comes under the class Asteroidea and holothurids comes under the class Holothuroidea. Sea star and Sea cucumber repectively represents the the classes Asteroidea and Holothuroidea. Regarding the symmetry exhibitted by sea stars, members of different families diverge from this theory by having more than five arms on the other hand holothurids diverged from this convention by exhibiting a superficial bilateral organization as a scondary modification. In the case of calcium rich ossicle plates, the sea urchins (holothurids) diverged by reducing it into widely separated micoscopic plates. Also most kinds of holothurids have tube feet in addition to tentacles.

C) Most similar classes among phylum Echinodermata are class Asteroidea and class Ophiuroidea. Prominent examples of these classes include, Star fish unde the class Asteroidea and brittle stars under the class Ophiuroidea. Both of them shares many common features icluding their prey capture mechanism in which both uses tube feet for prey capturing. Also in both the animals the sexes are separate. Along with that individuals from both classes brood their young ones in special cavities. These made the two classes similar.

D) Echinoderms are historically confused with phylum chordata. Because both exhibits deutrostomic development. Most other invertebrates exhibit protostomic development.

gladiator answered 5 months ago

Next > < Previous

Related Solutions

Phylum Echinodermata starfish dissection Starfish external structure examination Ide

Phylum Echinodermata starfish dissection Starfish external structure examination Identify: Oral surface Mouth Tube feet Ambulacral groove Aboral surface Arm Spines Central disk Madreporite List examples for the following classes. Class Asteroidea Class Ophiuroidea Class Crinoidea Class Echinoidea Class Holothuroidea

Describe the characteristics of Phylum Echinodermata and discuss how the body form varies in the 5...

Describe the characteristics of Phylum Echinodermata and discuss how the body form varies in the 5 classes zoology question

Prove that every subgroup of Q8 is normal. For each subgroup, find the isomorphism type of...

Prove that every subgroup of Q8 is normal. For each subgroup, find the isomorphism type of the corresponding quotient.

Striker has determined that the depreciable lives of several production machines are too long and thus...

Striker has determined that the depreciable lives of several production machines are too long and thus do not fairly match the cost of the assets with the revenue. They, therefore, decide to reduce the depreciable lives of those machines by three years. 1. Is this change allowed? If so, is it a –Change in accounting principle –Change in accounting estimate –Correction of an error in previously issued financial statements, or –Change in reporting entity 2. In what Period should this...

Prove that if a finite group G has a unique subgroup of order m for each...

Prove that if a finite group G has a unique subgroup of order m for each divisor m of the order n of G then G is cyclic.

In a finite cyclic group, each subgroup has size dividing the size of the group. Conversely, given a positive divisor of the size of the group, there is a subgroup of that size

Prove that in a finite cyclic group, each subgroup has size dividing the size of the group. Conversely, given a positive divisor of the size of the group, there is a subgroup of that size.

In each of the following, show that ? is a subgroup of ?. (1) 1. ?...

In each of the following, show that ? is a subgroup of ?. (1) 1. ? = 〈F(R), +〉, ? = {? ∈ F(R): ?(?)=0 for every ?∈[0,1]}. 2. ? = 〈F(R), +〉, ? = {? ∈ F(R): ?(?)=−?(?)}.

1. What are the four chordate shared characteristics (=synapomorphies) and what is the function of each...

1. What are the four chordate shared characteristics (=synapomorphies) and what is the function of each structure for a chordate animal? 2. The evolution of jaws is considered to be a key innovation in vertebrate evolution. What advantage do jawed vertebrates (gnathostomes) have when compared to jawless fishes (agnathan, hagfish and lamprey)? 3. What groups of vertebrates have an amniotic egg? What advantage do amniotes have over non-amniote vertebrates (e.g. fishes and amphibians)? 4. How did the origin of jaws,...

If p = 0.05 and the sample size of each subgroup is 150, then calculate the...

If p = 0.05 and the sample size of each subgroup is 150, then calculate the control limits for: a) p chart b) np chart

1,Tesla motors has been successful (thus far) in introducing several models of all-electric cars. They have...

1,Tesla motors has been successful (thus far) in introducing several models of all-electric cars. They have taken advantage of which of these forces? A) Technology Advances B) Economic Forces c) Social Trends D) Political and Regulatory Trends E) All of the above. 2) UMass Medical School discover a mono-clonal antibody that could prevent rabies from developing after a bite from a rabid animal. Which of these statement is NOT true. A) This is a great opportunity for pharmaceutical companies in the US. B)...

Subjects