Question

As a group, acoelomates are characterized by:
A. A body cavity called haemocoel
B. Deuterostome developments
C. A coelom that is not completely lined with mesoderm
D. A solid body without a cavity surrounding internal organ

Answer 1

Hint: There is a huge variation in structure of different organisms. An acoelomate is a creature that doesn't have body depression. Dissimilar to coelomates (eucoelomates), creatures with a genuine body cavity, acoelomates come up short on a liquid filled pit between the body divider and stomach related lot.

Complete step by step answer:
The characteristic features of acoelomates are listed as follows:
Acoelomates don't have a body pit or coelom. Coelom is the liquid-filled pit between the stomach and the body divider that additionally encompasses the other inward organs.
Not having a body hole, acoelomates have basic structures and need exceptionally created organ frameworks. For instance, acoelomates lack a cardiovascular framework and respiratory framework and depend on dispersion over their level, slight bodies for gas trade.
Acoelomates regularly have a basic stomach related lot, sensory system, and excretory framework.
The organisms belonging to phylum Platyhelminthes do not have coelom or body cavity.
Some organisms have a false coelom which is not continuous, that is termed as pseudocoelom.
Acoelomate examples include Planaria, Flukes, etc.
Among the given options, the correct alternative is 'A solid body without a cavity surrounding the internal organ, option (D).

Note:
-A genuine body holes structure just in multicellular creatures. Inside this gathering, the eumetazoa, an acoelomate is the most simple type of creature which has 3 genuine tissues. These tissues are the endoderm, mesoderm, and ectoderm, in a specific order from inside to out.
-In an acoelomate, these tissues contract consecutively, with no space in between.
-The organs are structured inside it, and are encircled by the mesoderm.