Assertion (A): Nematodes are pseudocoelomates.

Reason (R): Pseudocoelomates have a body cavity that is not fully lined with mesoderm.

a)
Both A and R are true, but R is not the correct explanation of A.

b)
A is true, but R is false.

c)
A is false, but R is true.

d)
Both A and R are true, and R is the correct explanation of A.

Correct answer is option 'D'. Can you explain this answer?

Question

Assertion (A): Nematodes are pseudocoelomates.

Reason (R): Pseudocoelomates have a body cavity that is not fully lined with mesoderm.

a)
Both A and R are true, but R is not the correct explanation of A.
b)
A is true, but R is false.
c)
A is false, but R is true.
d)
Both A and R are true, and R is the correct explanation of A.

Correct answer is option 'D'. Can you explain this answer?

Answer

Nematodes, or roundworms, are indeed classified as pseudocoelomates because they possess a body cavity, known as a pseudocoel, which is not completely lined by tissue derived from mesoderm.

Answer

Their shape comes from the fact that they, unlike earthworms, have no coelom (otherwise known as a fluid-filled body cavity). Therefore, Platyhelminthes are acoelomates ('a' meaning 'without').

Answer

Coelom and the Odd One Out

Coelom is a fluid-filled body cavity that is found in many animal phyla. It is derived from the mesoderm and is lined with a layer of mesodermal cells called mesothelium. The coelom plays an important role in the development and function of various organs and systems in animals.

In this question, we are asked to choose the odd one out based on coelom. Let us examine each option in detail:

a) Arthropods: Arthropods are a diverse group of animals that include insects, spiders, crustaceans, and others. They have a coelom that is reduced or absent in some groups, but is present in others. In general, arthropods have an open circulatory system, in which hemolymph (a fluid similar to blood) circulates freely throughout the body cavity.

b) Molluscs: Molluscs are another diverse group of animals that include snails, clams, squid, and others. They have a well-developed coelom that surrounds the heart and other organs. Molluscs have a closed circulatory system, in which blood circulates through vessels.

c) Annelids: Annelids are a group of segmented worms that includes earthworms, leeches, and others. They have a well-developed coelom that surrounds the digestive, circulatory, and reproductive organs. Annelids have a closed circulatory system, in which blood circulates through vessels.

d) Platyhelminthes: Platyhelminthes, or flatworms, are a group of animals that includes planarians, tapeworms, and others. They have a simple body plan with no body cavity or coelom. Instead, they have a solid body with a flattened shape that allows for gas exchange and nutrient uptake through diffusion.

Based on this information, we can conclude that the odd one out based on coelom is option d) Platyhelminthes, as they lack a coelom altogether. The other options all have a well-developed coelom that plays an important role in their anatomy and physiology.

Answer

Animalspossessing coelom are called coelomates, e.g.,annelids, molluscs, arthropods, echinoderms, hemichordates and chordates

Answer

arthropods

are coelomates with a true

coelom

,

molluscs

have developed a true

coelom

,

annelids

have a fluid-filled cavity between the outer body wall and the gut, and this is referred to as a

coelom

Platyhelminthes

are a phylum of worms that are flat in shape,

they are acoelomates

Answer

Rt under I in red 2D the r6 other 53 detect you interested in Tryon striking fine

Answer

Platyhelminthes is acoelomate I.e coelom is absent ......

Answer

Platyhelminthes

Answer

Platyhelminthes are acoelomates... while rest are coelomates..

Answer

Platyhelminthes because platyhelminthes is acoelomate and all are coelom

Answer

Platyhelminthes is pseudocoelomates animals

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