Cyclostomata are fish made of cartilage without a jaw made of bone

The correct answer for the blank is-

without a jaw.

Cyclostomata is a group of jaw-less fishes ( belonging to the super-class agnatha) under the phylum chordata.

It possesses the lampreys and hag-fishes, which are living jawless fishes.  Both these groups possess mouths without jaws. Their epidermal structures are sharp, which act as as teeth, and branchial arches are located internally (unlike jawed fishes, which have externally positioned branchial arches).

Thus, without a jaw is the right answer.

b.

events in order:

1.       vishnu schist

2. zoroaster granite

3. bass limestone

4. hakatar   shale

5. igneous intrusion

6. shinumo quartzite

7. dox sandstone

8. tapeats limestone

9. bright angel shale

10. muav limestone

11. temple butte limestone

12. redwall limestone  

nonconformity

answer: the unkar group shows angular unconformity because the layers are turned at angle.

unconformity

answer: specifically the angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled. an angular unconformity occurs between the cambrian and precambrian rocks. the dox sandstone, shinumo quartzite, hakatar shale, and bass limestone have been filled.

disconformity

answer: the disconformities aremarked irregular lines between the sedimentaryrocks layers.