Question

Phylum Echinodermata Discussion:

1. What is the favorite food of sea stars?

2. Which stomach can a sea star evert? What challenge(s) does this mechanism most likely help the sea start to cope with?

3. How do echinoderms cope with the other many challenges of multicellularity?

4. What are the advantages and disadvantages of having an endoskeleton?

5. Why are adult sea stars radially symmetric whereas larvae are bilaterally symmetric?

6. Echinoderms are deuterostomes and represent a different branch of the phylogenetic tree from the other phyla you have studied. How do they differ from these other phyla?

7. Echinoderms have no head and feature pentaradial symmetry. Can you make an argument, using many lines of evidence, for their close relation to chordates?

Answer 1

Answer 1)

Starfishsh are incredible trackers and essentially feed on mollusks. Their principle wellsprings of nourishment are shellfishes, clams sand dollars and mussels, which are typically appended to rocks or in any case incapable to escape rapidly. They likewise eat snails and harmed fish, when they can discover them.

Answer 2)

At the point when an ocean star takes care of, it can push the lower some portion of its stomach out through its mouth. The stomach at that point covers the prey and absorption starts.

A few animal varieties utilize their water vascular framework to open the shells of certain mollusks and infuse their stomachs into the shells. It at that point processes the mollusk set up. Somewhat processed nourishment is passed to within the starfish where assimilation proceeds in the pyloric stomach. The ocean star's arms are loaded up with stomach related organs called pyloric caeca which help with assimilation. These stomach related organs emit proteins and retain required nutrients from nourishment.

Thus, this eversion helps them to process better digestion

Answer 3 )

The other multicellularity challenge ofechinoderms is -

•Echinoderms don't seem to have any components for osmoregulation, and keep their body liquids at a similar salt focus as the encompassing water. Albeit a few animal groups can endure moderately low saltiness, the absence of an osmoregulation framework. Multicellularity needs better osmoregulation.

They cope up with the situation as -

In echinoderm, nitrogenous waste is traveled through their cylinder feet and papulae (Osmoregulation). The coelomocytes then inundate the waste and afterward move to the tip of the papulae (Osmoregulation). The creature's divider is then cut open, and the waste is discharged into the general condition (Osmoregulation).

•Echinoderm faces a tricky challeng that, They have to discharge cement from their cylinder feet to abstain from escaping by flows, however the emissions' tenacity must be reversible so the creature can move around to look for nourishment.

They cope up with the situation by using there sticky tentacles and foots to save themselves from currents.

Answer 4)

Advantages of endoskeleton -

•An endoskeleton is a structure that holds a creature from inside.

•An endoskeleton permits the body to move and gives the body structure and shape.

•A genuine endoskeleton creates from mesodermal tissue. Such a skeleton is available in echinoderms and chordates.

•A significant preferred position of an endoskeleton over an exoskeleton is that the endoskeleton offers progressively basic help.

•Endoskeletons hold ones inner parts together.

Disadvantage of endoskeleton is -

impediments incorporate less assurance and influence for muscles.

Answer 5)

The larvae possess bilaterally symmetrical structure because -

When Echinoderms are in danger, they tend to use their bodily functions efficiently and bilaterally, the bilaterally symmetrical structure helps them to run fast from the catch of predators.

Echinoderm larvae are ciliated, free-swimming organisms that organize in bilateral symmetry which makes them look like embryonic chordates.

So, for the protection purposes and to save their lives and better growth and development Echinoderms larvae are bilaterally symmetrical.

The adult possess radially symmetrical structure because -

Echinoderm adults will in general act progressively like radial creatures with the goal that they can be available to boosts from all headings and move uniformly toward various bearings.

So, this will help to catch pray as they get better stimuli from all the directions and even they can save themselves too by the same mechanism.

Answer 6)

Deuterostomes are otherwise called enterocoelomates in light of the fact that their coelom creates through enterocoely. There are three significant clades of deuterostomes: Chordata (vertebrates and their family) Echinodermata (starfish, ocean urchins, ocean cucumbers).

One exceptionally one of a kind element of echinoderms is a sorted out system of trenches all through the body called the water vascular framework that capacities in motion, taking care of, discharge, and breath. The water vascular framework utilizes water pressure produced through muscle withdrawals to move the life form.

Answer 7 )

Echinoderms are closely related to chordata as -

Echinoderms and Chordates are more firmly identified with one another than they are to different creatures in light of the fact that the coelom ( an open liquid filled body cavity fixed with tissues) found in the creatures of this phylum is produced using the stomach related cylinder and the endoskeleton present in the body are made out of 95% of calcium carbonate