The answer that best fits the blank provided above is C3a and C5a. Mast cells release this so called histamines once they are exposed to C3a and C5a which are fragments of complement proteins. These are also called as <span>Anaphylatoxins along with C4a. Hope this helps.</span>
In metaphase I of meiosis I, the pairs of homologous chromosomes, also known as bivalents or tetrads, line up in a random order along the metaphase plate. The random orientation is another way for cells to introduce genetic variation.
D. Carnivores that eat other animals
A biotic factor is a living organism that shapes its environment.
Answer: Photosynthesis
Explanation: Photosynthesis removes CO2 from the atmosphere and replaces it with O2. Respiration takes O2 from the atmosphere and replaces it with CO2.