Which one of the options correctly represents organisms from the subphyla Chelicerata, Myriapoda, and Hexapoda, in this specific sequence?
Horseshoe crabs, centipedes, springtails
Organisms in Chelicerata, Myriapoda, and Hexapoda
The question asks to identify the option that correctly lists organisms from three specific subphyla of the phylum Arthropoda: Chelicerata, Myriapoda, and Hexapoda, in that exact order.
Let's understand each subphylum:
- Chelicerata: This subphylum includes arthropods characterized by having chelicerae (appendages near the mouth). They typically have two main body segments: a cephalothorax (prosoma) and an abdomen (opisthosoma). Most Chelicerata have eight legs. Examples include spiders, scorpions, mites, ticks, and horseshoe crabs.
- Myriapoda: This subphylum consists of arthropods with elongated bodies divided into many segments, each bearing one or two pairs of legs. They typically have a single pair of antennae and simple eyes. Examples include centipedes and millipedes.
- Hexapoda: This is the largest subphylum of arthropods, primarily comprising insects. Hexapods are characterized by having three distinct body segments: head, thorax, and abdomen. The thorax usually bears three pairs of legs (hence "Hexapoda," meaning six legs). Examples include insects (like beetles, flies, butterflies) and other related groups like springtails.
Now, let's examine each option provided and see if the organisms match the sequence: Chelicerata, Myriapoda, Hexapoda.
- Option 1: Arachnids, horseshoe crabs, centipedes
- Arachnids belong to Chelicerata.
- Horseshoe crabs belong to Chelicerata.
- Centipedes belong to Myriapoda.
- The sequence is Chelicerata, Chelicerata, Myriapoda, which is incorrect.
- Option 2: Horseshoe crabs, centipedes, springtails
- Horseshoe crabs belong to Chelicerata.
- Centipedes belong to Myriapoda.
- Springtails (Collembola) belong to Hexapoda.
- The sequence is Chelicerata, Myriapoda, Hexapoda, which is the correct order.
- Option 3: Lobsters, millipedes, silverfish
- Lobsters belong to Crustacea (another subphylum of Arthropoda).
- Millipedes belong to Myriapoda.
- Silverfish belong to Hexapoda (specifically Class Insecta).
- The sequence is Crustacea, Myriapoda, Hexapoda, which is incorrect.
- Option 4: Arachnids, insects, crabs
- Arachnids belong to Chelicerata.
- Insects belong to Hexapoda.
- Crabs belong to Crustacea.
- The sequence is Chelicerata, Hexapoda, Crustacea, which is incorrect.
Based on the classification of the organisms into their respective subphyla, Option 2 correctly follows the specified order of Chelicerata, Myriapoda, and Hexapoda.
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.
