The terms expressing some of the developmental events or specific body structures are given in column X and the names of animals that are associated with them in column Y: Column X Column Y A Torsion (i) Star fish B Metagenesis (ii) Obelia C Apolysis (iii) Taenia D Pedicellaria (iv) Apple snail The correct match of the terms in column X with the name of animals in column Y is:
Matching Animal Terms and Structures
This question asks us to match specific biological terms related to developmental events or body structures with the animals in which they occur or are found. Let's look at each term and identify its associated animal.
- Torsion: This is a unique developmental process primarily found in Gastropods (a class of molluscs). During larval development, the visceral mass rotates 180 degrees relative to the head and foot. This results in the anus and mantle cavity being positioned anteriorly, near the head. The Apple snail is a well-known Gastropod. Therefore, Torsion is associated with the Apple snail.
- Metagenesis: This term describes the alternation of generations seen in the life cycle of certain animals, particularly some Cnidarians. It involves alternating between a sessile polyp stage and a free-swimming medusa stage. Obelia is a colonial hydrozoan (a type of Cnidarian) that exhibits this pattern of alternation between polyp and medusa forms. So, Metagenesis is associated with Obelia.
- Apolysis: In the context of shedding or casting off, Apolysis refers to the separation of the cuticle from the epidermis prior to molting. While primarily associated with arthropods, a similar process of shedding segments (proglottids) occurs in some flatworms (Platyhelminthes), like tapeworms, as part of strobilation. Taenia is a genus of tapeworm. Therefore, Apolysis can be associated with Taenia in this context of segment shedding.
- Pedicellaria: These are small, pincer-like or jaw-like structures found on the surface of echinoderms, especially sea stars (starfish) and sea urchins. They have various functions, including defense, cleaning the body surface, and sometimes capturing small prey. The Star fish is an echinoderm and possesses pedicellariae. Hence, Pedicellaria is associated with Star fish.
Summary of Matches
Based on the analysis above, we can form the following matches:
- Torsion (A) is associated with Apple snail (iv).
- Metagenesis (B) is associated with Obelia (ii).
- Apolysis (C) is associated with Taenia (iii).
- Pedicellaria (D) is associated with Star fish (i).
This gives us the combination A - iv, B - ii, C - iii, D - i.
Verifying the Option
Let's construct a table to clearly see the matching pairs:
| Column X (Terms) | Column Y (Animals) | Match |
|---|---|---|
| A. Torsion | (iv) Apple snail | A - iv |
| B. Metagenesis | (ii) Obelia | B - ii |
| C. Apolysis | (iii) Taenia | C - iii |
| D. Pedicellaria | (i) Star fish | D - i |
The matching pairs are A - iv, B - ii, C - iii, D - i. We need to find the option that correctly represents this combination.
Important Questions from Diversity of Life Forms
The following table shows common millets (Column X) and their scientific names (Column Y):
Column X
Column Y
A.
Ragi (Finger millet)
i.
Eleusine coracana
B.
Jowar (Great millet)
ii.
Paspalum scrobiculatum
C.
Kodo millet
iii.
Pennisetum typhoides/ glaucum
D.
Bajra (Pearl millet)
iv.
Sorghum bicolor
Which one of the following options represents the correct match between Column X and Column Y?
Which one of the following fossils is no longer considered to be a true vascular plant based on the structure of the secondary thickening of the conducting elements?
Select the correct former name for The International Code of Nomenclature (ICN) which was changed as part of the Melbourne code.
Based on the reported estimates of biodiversity in India, select the correct option that represents the decreasing order of total number of species reported in these taxa.
Select the rare or endangered species which also have exceptionally low genetic variability, as documented by multi-locus molecular methods.
