Answer
Verified
414.6k+ views
Hint: Echinoderms come under the kingdom Animalia. They are the major group of only marine animals. The echinoderms are characterized by the hard, spiny covering or skin.
Complete Answer:
Arms generally refer to limbs. Spines are hard, needle like structures that help in defense of any organism. Pedicellariae are also the defensive organs like a minute pincer.
1. Star fishes: Starfish is also known as the sea start. It is a star shaped echinoderm belonging to class Asteroidea that’s why they are also called as the Asteroids.
- Starfishes are the marine invertebrates. Starfishes usually have 5 arms and their upper surface is spiny that means they contain spines.
- In sea fishes, there are no pedicellariae.
2. Sea cucumber: Sea cucumbers belong to the class Holothuroidea. They are marine animals with leathery skin and elongated bodies.
- Sea cucumbers are found on the seafloor world wide. Sea cucumber helps in the breakdown of detritus and other organic matter, and helps in recycling nutrients in the marine ecosystem. Sea cucumbers have no arms, no spines and no pedicellariae.
3. Sea Lily: Sea lilies belong to the class Crinoidea of phylum Echinodermata.
- Sea lilies resemble the plant more than an animal. The members of class crinoidea include the feather stars.
- Sea lilies have branched arms. They have no spines and pedicellariae.
4. Sea urchin: Sea urchin belong to the class Echinoidea of phylum Echinodermata.
They are typically spiny.
- Sea urchins have spines and pedicellariae. They have no arms and no spines.
Hence, option b is the right answer for this question.
Note: Echinoderms have radial symmetry. The members of echinoderms have five or multiple of five arms. They all have a shell which is made up of calcium carbonate and covers the skin.
Complete Answer:
Arms generally refer to limbs. Spines are hard, needle like structures that help in defense of any organism. Pedicellariae are also the defensive organs like a minute pincer.
1. Star fishes: Starfish is also known as the sea start. It is a star shaped echinoderm belonging to class Asteroidea that’s why they are also called as the Asteroids.
- Starfishes are the marine invertebrates. Starfishes usually have 5 arms and their upper surface is spiny that means they contain spines.
- In sea fishes, there are no pedicellariae.
2. Sea cucumber: Sea cucumbers belong to the class Holothuroidea. They are marine animals with leathery skin and elongated bodies.
- Sea cucumbers are found on the seafloor world wide. Sea cucumber helps in the breakdown of detritus and other organic matter, and helps in recycling nutrients in the marine ecosystem. Sea cucumbers have no arms, no spines and no pedicellariae.
3. Sea Lily: Sea lilies belong to the class Crinoidea of phylum Echinodermata.
- Sea lilies resemble the plant more than an animal. The members of class crinoidea include the feather stars.
- Sea lilies have branched arms. They have no spines and pedicellariae.
4. Sea urchin: Sea urchin belong to the class Echinoidea of phylum Echinodermata.
They are typically spiny.
- Sea urchins have spines and pedicellariae. They have no arms and no spines.
Hence, option b is the right answer for this question.
Note: Echinoderms have radial symmetry. The members of echinoderms have five or multiple of five arms. They all have a shell which is made up of calcium carbonate and covers the skin.
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
Why Are Noble Gases NonReactive class 11 chemistry CBSE
Let X and Y be the sets of all positive divisors of class 11 maths CBSE
Let x and y be 2 real numbers which satisfy the equations class 11 maths CBSE
Let x 4log 2sqrt 9k 1 + 7 and y dfrac132log 2sqrt5 class 11 maths CBSE
Let x22ax+b20 and x22bx+a20 be two equations Then the class 11 maths CBSE
Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
At which age domestication of animals started A Neolithic class 11 social science CBSE
Which are the Top 10 Largest Countries of the World?
Give 10 examples for herbs , shrubs , climbers , creepers
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Difference Between Plant Cell and Animal Cell
Write a letter to the principal requesting him to grant class 10 english CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
Fill in the blanks A 1 lakh ten thousand B 1 million class 9 maths CBSE