Question

The structures furcula, urostyle, endostyle are present respectively in
A. Pave, Rhacophorus, Branchiostegal
B. Causeries, Guggenheims, Amphioxus
C. Apteryx, Rana, Ascidia
D. Pave, Proteus, Prosoma

Answer 1

Hint: The furcula or wishbone is a forked bone found in birds and some other species of dinosaurs, and is formed by the fusion of the two clavicles. Rhacophorus is a genus of frogs in the shrub frog family (Rhacophoridae) which together with the related Halide makes up the true tree frogs. These frogs have long toes with strong webbing between them, enabling the animals to slow their fall to a glide, a form of arboreal locomotion. The endostyle is an anatomical feature found in all chordates. It is an organ that assists chordates in filter-feeding.

Complete answer: The furcula works as a strut between a bird's shoulders and articulates to each of the bird's scapulae. In conjunction with the coracoid and the scapula, it forms a unique structure called the trios seal canal, which houses a strong tendon that connects the supracoracoideus muscles to the humerus. This system is responsible for lifting the wings during the recovery stroke.
-A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura. The characteristics of anuran adults include 9 or fewer presacral vertebrae, the presence of a urostyle formed of fused vertebrae, no tail, a long and forward-sloping ilium, shorter forelimbs than hind limbs, radius and ulna fused, tibia and fibula fused, elongated ankle bones, absence of a prefrontal bone, presence of a hyoid plate, a lower jaw without teeth consisting of three pairs of bones, an unsupported tongue, lymph spaces underneath the skin, and a muscle, the protractor lentils, attached to the lens of the eye.
-Endostyle is found in adult urochordates and cephalochordates; as well as in the larvae of the vertebrate lampreys but has been transformed through evolutionary time into the thyroid in all other vertebrates. Since the endostyle is found in all three branches of chordates, it is presumed to have arisen in the common ancestor of these taxa, along with a shift to internal feeding for extracting suspended food from the water.
Hence, the correct option is (A)-Pave, Rhacophorus, Branchiostegal

Note: An adult frog has a stout body, protruding eyes, anteriorly-attached tongue, limbs folded underneath, and no tail. Frogs have glandular skin, with secretions ranging from distasteful to toxic. Frogs typically lay their eggs in water. The eggs hatch into aquatic larvae called tadpoles that have tails and internal gills. They have highly specialized rasping mouthparts suitable for herbivorous, omnivorous, or planktivorous diets. The life cycle is completed when they metamorphose into adults. In Pave, as the thorax is compressed by the flight muscles during the downstroke, the upper ends of the furcula spread apart, expanding by as much as 50% of its resting width, and then contracts.