One of the many changes are the seasons, ex Winter, Spring, Summer, Fall
Commensalism is an interaction in which one individual benefits while the other is neither helped nor harmed. Example: Orchids (example of epiphytes)
<span>Mitosis is a part of the cell cycle in which chromosomes in a cell nucleus are separated into two identical sets of chromosomes, and each set ends up in its own nucleus.</span>
The correct answer is: c. An operon is a region of DNA that codes for a series of functionally related genes under the control of the same promoter.
Operons contain cluster of genes that are transcribed together into mRNA or are not expressed at all. Formed mRNA undergos splicing to create monocistronic mRNAs so that can be translated separately. Operons are more often found in prokaryotic cells but it can appear in eukaryotic cells and in viruses.
1.
The first prokaryotic cells (the less complex in its organization and with no organelles involved in membranes) evolved about 3.5 billion years ago. Therefore, the correct answer is D. 3.5 billion.
2.
Then, some prokaryotic cells evolved to use the sunlight to produce energy and release O2 into the atmosphere about 2.8 billion years ago. Therefore, the correct answer is C. 2.8 billion.
3.
After that, the prokaryotic cells evolved to cells with organelles bounded by membranes, and then the eukaryotic cells evolved about 2.5 billion years ago. Therefore, the correct answer is B. 2.1 billion.
4.
A long time after that, aproximately 650 million years, the first life composed of an organism with multiple cells evolved. Therefore, the correct answer is A. 650 million.
