7) A) secondary oocyte; vesicular follicle B) secondary oocyte; secondary follicle C) ovum(egg); vesicular follicle D) primary oocyte; secondary follicle Answer: A 8) Development of the oocyte and follicular growth occur in the ________ of the ovary. 8) This is the end of the preview.
Evolution of the atmosphere. Scientists believe that the Earth was formed about 4.5 billion years ago. Its early atmosphere was probably formed from the gases given out by volcanoes. It is believed that there was intense volcanic activity for the first billion years of the Earth's existence.The early atmosphere was probably mostly carbon dioxide, with little or no oxygen.There were small quantities of water vapour, ammonia and methane. As the Earth cooled down, most of the water vapour condensed and formed the oceans.ts early atmosphere was probably formed from the gases given out by volcanoes. It is believed that there was intense volcanic activity for the first billion years of the Earth's existence. The early atmosphere was probably mostly carbon dioxide, with little or no oxygen.
Describe the major events in the history of life during the Precambrian. The early atmosphere formed as gases - including water vapor, carbon dioxide, and nitrogen - were released from inside Earth. Describe the formation and composition of Earth's atmosphere early in the Precambrian. A shield is a large part of Precambrian rock that forms the core of a continent.