The fossil record is used to divide Earth's history into geologic time periods. The figure below shows the four major subdivisions of geologic time—eons, eras, periods, and epochs. Eons are the longest subdivision and are based on the abundance of certain fossils. Eons are divided into smaller time periods called eras
<span>The correct answer is B. Spores. Spores participate in both sexual and asexual reproduction unlike eggs and sperm which is found only in sexual, and seeds that are found in plant reproduction. There are many different types of spores based on many classifications, so there is also those who participate in sexual reproduction and those who participate in asexual reproduction.</span>
Some natural processes record the variations in time. For example, the sediments found on the rocks acts to be the great proof of the climate that existed in olden times.
Explanation:
Paleoclimatology is the study of climate records from hundreds to millions of years ago. Information for paleoclimate studies come from natural records. One of the most important natural record from which enormous information about the past climate can be known from the tree ring data. Another source include lake and ocean sediments that are found on the rocks and glaciers.
By measuring the width of Sample of tree rings, sediments , corals and ice, the chemical composition, and physical structure of each layer, scientists can also investigate the conditions present when each layer formed. The data of the natural records can be trusted as these prove to be the greatest source of study of ancient civilizations and how they survived in extreme climatic conditions.
