Answer:
Answered below
Explanation:
In the 1920s, Russian Chemist A.I Oparan and English geneticist Haldane, first conceived and developed independently, the theory of Primordial soup. The primordial soup theory suggests that life began in a pond or ocean as a result of the combination of the right amounts of chemicals from the atmosphere and some form of energy, under the right conditions, which resulted in the production of amino acids, the building blocks of proteins from which life evolved. This is suggested to have happened 3 to 4 billion years ago.
This theory was tested by Chemist Stanley Miller and Physicist Harold Urey, in 1950. They mixed gases thought to be present in the primitive earth and electrically sparked the mixture, which resulted in the formation of amino acids.
The Biosphere, is the layer of the planet Earth were life exists.
Answer:
target cell
Explanation:
Cell communication includes one or more signaling cells and the target cell. Signaling cells produce signals. In the case of chemical signaling, the signaling cells produce chemical signals such as hormones or neurotransmitters or ligands. Target cells are the cells that respond to a specific signal produced by the signaling cell.
To receive and respond towards the signal, the target cells produce receptors where the signaling molecules bind to produce the desired effects in the target cells. For instance, liver and muscle cells are one of the primary target cells for the pancreatic hormone insulin.
Being male because it is proven that males are more intend for self harm and suicide. And having a history of neglect or sexual or physical abuse because the person feels as if they are worthless or they are empty or full of sadness or depression.
