23. the first invertebrates to develop a true nervous system are a.coelenterates b.arthropods c.annelids d.sponges 28. the sequence of ear ossicles starting from the eardrum is a.incus, stapes, malleus b.malleus, stapes, incus c.malleus, incus, stapes d.stapes, incus, malleus 29. which of the following is not a viral disease of man? a.small pox b.influenza c.whooping cough d.rabies 30. gametophytic generation is dominant in a.gymnosperms b.pteridophytes c.angiosperms d.bryophytes
Correct option is B) The middle ear consists of three bones or ossicles: Malleus (hammer)Incus (anvil)Stapes (stir-up) These bones are attached to each other in a chain-like manner. Malleus is attached to tympanic membrane whereas stapes is attached to oval window of cochlea. Hence, the sequence of ear ossicles from outside to inside is: malleus, incus and stapes. So, the correct answer is 'Malleus, incus and stapes'.
