Question

The pronephros a. is located most caudally and degenerates in higher mammals b. is derived from the nephrotome and contains nephrostomes and glomus c. fuses with the cloaca d. & c e. a, b, & c The optic vesicie gives rise the _____ which becomes a two layered structure that gives rise to the _____ the site where sensory receptors are located a. optic cup, retina b. optic stalk retina c. optic cup lens d. optic stalk choroid e none of these In the formation of skeletal muscles spindle shaped _____ migrate to the region of the location of a muscle and fuse to form _____ which form premuscle masses. a mesenchyme myoblast b. myoblasts myotubes c. myoblasts Sarcomere d. myofibers myoblasts e. myofibers nature muscles Cranial and cervical muscles are derived from a. somitoneres b. ventrolateral mesoderm c. dorsal mesoderm d. splanchnopleure The embryonic skeleton is formed mainly by _____ structure a cartilaginous b osteogenous c fibrous d. a & b e. a, b & c Neurons are derived from specialized cells called a neurites b. neuroglia c. neuroblasts d. neuroepithelium e. astrocytes

Answer 1

7. the Pronephros is locatedmost caudally and degenerates in higher mammals and fuses with cloaca that is both a & c.

8. The optical vesicle gives rise to optic cup,which becomes a 2 layered structure that gives rise to the retina the site where sensary receptars are initiated.

9.In the formation of skeletal muscles, the spindle shaped myoblasts migrate to the regions of of the location of a muscle and fuse to form myotube which form promuscle masses.

10. Cranial and cervical muscles are derived from somitomeres

11. The embryonic skeleton is mainly formed by Cartilagenous and Osteogenous that both a & b.

12. Neurons are derived from specialliazed cells astrcytes

13. Of the three different layers making up interior of central nervous system in the early embryo the mantle layer becomes neural tube. This question was not clear answered according to subject knowledge.