Question

Which is the last pair of appendages in lobsters, prawn, etc that provide swift backward motion and help protect developing young ones.
(a) Uropods
(b) Pleopods
(c) Telson
(d) Parapods

Answer 1

Hint: Biramous appendages which are also called tail fans present in the telson region of the last segment of the abdomen that helps in escape and protection.

Complete answer:
Lobsters and prawns belong to the phylum Arthropoda and class crustacea. There are five pairs of appendages seen in crustaceans. Uropods are the pair of appendages present on the last segment of the body i.e, abdomen near telson which helps in protection and escape.

Additional Information: - The phylum Arthropoda is divided into three subphyla: trilobite, Chelicerata, mandibulata
- The subphylum Chelicerata is classified into two classes: Xiphosura, Arachnida
- The subphylum mandibulata is classified into four classes: Crustacea, Chilopoda, Diplopoda, and Insecta. Insecta is the largest class of arthropods and Arthropods is the largest phylum
- Lobsters, prawns, and crabs come under the class crustacea. Their body is divided into head body and neck.
- They contain five segments and each segment contains a pair of biramous appendages. Antennae are the pair of appendages present in all the crustaceans
- The first pair of appendages are called protopod which is divided into exopod and endopod
- Pereopods are paired appendages present in the thorax which helping in walking and clinging
- Pleopod are paired appendages present in the abdomen region helps in respiration, swimming, holding offspring
- Uropods are the last pair of appendages present in the last abdominal segment called tesla which helps in the escape and protection of young ones. Uropods are also called tail fan
So, the correct answer is ‘uropods’

Note: The presence of a pair of antennae in the cephalic region is a unique feature of crustaceans which is the only appendage that is present in all crustaceans.
All the appendages present in the thoracic and abdomen regions are biramous.