Question 1

Platyhelminthes are commonly called ______ and their excretion is carried out by ______:

Accepted Answer

Flatworms; flame cells. Flatworms are dorsoventrally flattened; osmoregulation/excretion is by protonephridia (flame cells).

Question 2

Aschelminthes (e.g. Ascaris) are commonly called:

Accepted Answer

Roundworms. Aschelminthes have a circular cross-section — the roundworms.

Question 3

Platyhelminthes are ______ while Aschelminthes are ______ with respect to the body cavity:

Accepted Answer

Acoelomate; pseudocoelomate. Flatworms lack a body cavity (acoelomate); roundworms have a pseudocoelom (not lined fully by mesoderm).

Question 4

A parasitic flatworm example and a parasitic roundworm example are, respectively:

Accepted Answer

Taenia (tapeworm); Wuchereria (filaria worm). Taenia and Fasciola are flatworms; Ascaris, Wuchereria and Ancylostoma (hookworm) are roundworms.

Question 5

Sexual dimorphism (males and females distinct) is a notable feature of:

Accepted Answer

Aschelminthes (roundworms). In roundworms, sexes are separate and often show clear dimorphism (e.g. male Ascaris smaller with a curved tail).

Question 6

Which set of features is correct for Platyhelminthes?

Accepted Answer

Triploblastic, acoelomate, bilaterally symmetrical, organ-level. Flatworms are the first triploblastic, bilaterally symmetrical, acoelomate animals at the organ level of organisation.

Question 7

With respect to symmetry and germ layers, flatworms (Platyhelminthes) are:

Accepted Answer

Bilaterally symmetrical and triploblastic. Platyhelminthes are the first bilaterally symmetrical and triploblastic animals, though they remain acoelomate (no body cavity).

Question 8

A tapeworm (Taenia) absorbs digested nutrients from its host mainly through its:

Accepted Answer

General body surface. Tapeworms have no digestive system; they absorb the host's pre-digested food directly across the general body surface (tegument).

Question 9

A feature that distinguishes Aschelminthes (roundworms) from Platyhelminthes is that Aschelminthes possess a:

Accepted Answer

Complete digestive tract with both mouth and anus. Aschelminthes have a complete alimentary canal with a distinct mouth and anus, whereas the flatworm gut, when present, is incomplete with only a single opening.

Question 10

Assertion (A): Platyhelminthes are described as acoelomate animals. Reason (R): The space between the body wall and gut is packed with mesodermal parenchyma, leaving no true cavity. Choose the correct option.

Accepted Answer

Both A and R are true and R is the correct explanation of A. Flatworms lack a body cavity because the region between gut and body wall is filled with parenchyma, making them acoelomate; both statements are true and R explains A.

Question 11

Which of the following statements about Aschelminthes is correct?

Accepted Answer

They are pseudocoelomate, have a complete gut and often show sexual dimorphism. Roundworms possess a false coelom (pseudocoelom), a complete alimentary canal, and are usually dioecious with distinct males and females (sexual dimorphism).

Question 12

Match the parasite with its common name — (i) Taenia, (ii) Fasciola, (iii) Wuchereria, (iv) Ancylostoma:

Accepted Answer

i-tapeworm, ii-liver fluke, iii-filaria worm, iv-hookworm. Taenia is the tapeworm, Fasciola the liver fluke (both Platyhelminthes), while Wuchereria (filaria worm) and Ancylostoma (hookworm) are Aschelminthes.

Question 13

An animal has a dorso-ventrally flattened body, is an endoparasite in humans, and lacks any body cavity. To which phylum does it belong?

Accepted Answer

Platyhelminthes. A flattened (flatworm) body, endoparasitic habit and the acoelomate condition are diagnostic of Platyhelminthes.

Question 14

A worm has a body that is circular in cross-section, a complete gut and a false body cavity (pseudocoelom). Which phylum does it belong to?

Accepted Answer

Aschelminthes. A round (circular in cross-section) body, complete alimentary canal and a pseudocoelom identify Aschelminthes (roundworms).

Question 15

Taenia and Fasciola are usually cited as examples of which phylum?

Accepted Answer

Platyhelminthes. Taenia (tapeworm) and Fasciola (liver fluke) are parasitic flatworms of phylum Platyhelminthes.

Question 16

Ascaris, Wuchereria and Ancylostoma are all examples of which phylum?

Accepted Answer

Aschelminthes. Ascaris (roundworm), Wuchereria (filaria worm) and Ancylostoma (hookworm) are all aschelminthes (roundworms).

Question 17

Which flatworm is well known for its very high capacity to regenerate?

Accepted Answer

Planaria. Among platyhelminthes, Planaria possesses a high regeneration capacity.

Question 18

The liver fluke, an example of Platyhelminthes, is the common name of which genus?

Accepted Answer

Fasciola. Fasciola is the liver fluke, while Taenia is the tapeworm.

Question 19

Ancylostoma is commonly known as the:

Accepted Answer

Hookworm. Ancylostoma is the hookworm, a parasitic roundworm belonging to Aschelminthes.

Question 20

The genus Wuchereria is commonly called the:

Accepted Answer

Filaria worm. Wuchereria is the filaria worm; the plain roundworm is Ascaris.

Platyhelminthes & Aschelminthes — NEET Biology MCQs with Solutions

Questions with solutions