What is in the topmost layer of soil called the o horizon?

Coquina, a type of limestone, forms from shell fragments that settle on the ocean floor. what type of rock is coquina?

Svetlana and her mother are very similar. both have blonde hair, a love of scrapbooking, blue eyes, and a thin nose. which statement  most likely  describes svetlana’s traits? svetlana inherited her love of scrapbooking from her mother, but her blue eyes come from her environment. svetlana inherited her blue eyes from her mother, but her love of scrapbooking comes from her environment. svetlana inherited her thin nose from her mother, but her blonde hair comes from her environment. svetlana inherited her blonde hair from her mother, but her thin nose comes from her environment.

Genetic disorders can result when sister chromatids fail to seperate properly. during what phase is this problem most likely to occur?