The different types of cellular signals are: Intracrine signals (this signal is produced by the target cell that stays within the target cell), Autocrine signals (this signal is produced by the target cell, are secreted, and this can affect the target cell itself via receptors). Cells can comunicate with one another through direct cell membrane contact or the cell can release signal molecules into the blood stream.
Hope this helps!! (if it doesn't I'm sorry!)
<span>Messages would not be sent to the inside of the cell.</span>
<span>Presence of oxygen means that the organisms are not anaerobic so the answer is D. algae. Eukaryotic and prokaryotic cells can be anaerobic meaning that they live in circumstances where there's no oxygen. Algae were the first that required oxygen to thrive. Cyanobacteria are like other bacteria parts of the prokaryotic cell type.</span>
The right answer is A.
During the cell cycle, the amount of DNA in the nucleus varies: it doubles during interphase, allowing the daughter cells to receive an amount equal to that initially present in the mother cell. During mitosis, the daughter cells thus receive the same number of chromosomes, which is equal to that of the mother cell. Mitosis is a consistent mode of reproduction. The number of chromosomes, which is characteristic of the species (46 in the human species, 23 pairs), is therefore kept constant during successive cell cycles.