During the early stages of meiosis, two chromosomes in a homologous pair may exchange segments, producing genetic variation in sex cells. this process of exchange is called a) transcription. b) crossing over. c) nondisjunction. d) genetic shuffling.

The correct answer is option B, that is, crossing over.  

Crossing over or chromosomal crossover refers to the interchange of genetic substance between the two homologous chromosomes non-sister chromatids, which leads to the formation of recombinant chromosomes at the time of sexual reproduction.  

It takes place in the pachytene stage of prophase I of meiosis at the time of a procedure known as synapsis.  

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.