Match the following group of organisms with their
respective distinctive characteristics and select the correct option :
Organisms
Characteristics
(A)Platyhelminthes
(I)Cylindrical body with no segmentation
(B)Echinoderms
(II)Warm blooded
animals with direct development
(C)Hemichordates
(III)Bilateral symmetry with incomplete
digestive system
(D)Aves
(IV)Radial symmetry with indirect
development
Choose the correct answer from the options given below:
Explanation:
Matchings as per NCERT:
- Platyhelminthes (A) have bilateral symmetry and are unsegmented with an incomplete digestive system (only one opening). => (III)
- Echinoderms (B) show radial symmetry as adults and have indirect development (larval stage). => (IV)
- Hemichordates (C) are worm-like, unsegmented (cylindrical body, no segmentation) organisms. => (I)
- Aves (D) are warm-blooded and show direct development (hatching resembles the adult). => (II)
Thus the correct pairing is A-III, B-IV, C-I, D-II. The other options mismatch these standard NCERT characteristics.
🧠 Did You Know?
Hemichordates and Echinoderms are considered deuterostomes, like chordates, in embryology.
Which of the following statements are true for
the phylum-Chordata?
(A) In Urochordata notochord extends from head to tail and it is present throughout their life.
(B) In Vertebrata notochord is present during the embryonic period only.
(C) Central nervous system is dorsal and hollow.
(D) Chordata is divided into 3 subphyla : Hemichordata, Tunicata and Cephalochordata.
Consider following features:
(A) Organ system level of organisation
(B) Bilateral symmetry
(C) True coelomates with segmentation of body
Select the correct option of animal groups which
possess all the above characteristics.
Explanation:
The correct option is 2: Annelida, Arthropoda and Chordata. All three groups show organ system level of organisation and bilateral symmetry. They are true coelomates and exhibit body segmentation (Annelida and Arthropoda are clearly segmented;Chordata shows segmentation in its body plan, such as somites in many groups). Thus they possess all the features listed: organ-system level, bilateral symmetry, and true coelomate with segmentation.
🧠 Did You Know?
While Mollusca are bilaterally symmetrical and coelomate with organ systems, they are not typically described as having true body segmentation like Annelids or Arthropods in the NCERT context.
💡 NCERT Memory Line:
Organ system level, bilateral symmetry, and true coelom with segmentation are characteristic of Annelida and Arthropoda; Chordata also shows segmentation in its body plan.
