The answer is; A
This model hypothesizes how life started during the early conditions of the earth which were hot and filled with greenhouse gases in its atmosphere about 4 billion years ago. It is explained by the theory of spontaneous generation where organic molecules were created from inorganic molecules spurred from energy from lightning. These organic molecules filled the water bodies and chemically arranged themselves, over time, into primordial life.
The property of all ionic compounds that makes chalk particularly useful for writing on a chalkboard is : Hardness and Brittleness
Those properties make chalk leaves residues on the board every time friction happen between the chalk and the board
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Answer:
All of the above.
Explanation:
Reflex arc may be defined as the neural pathway that control the function of the reflex system of the body. Two main types of reflex arc are somatic reflex arc and autonomic reflex arc.
The afferent neuron carries signal from the receptors to the integrating center via the interneuron. The efferent neuron carries signal from the integrating center to the effector organ via the inter neuron.
Thus, the correct answer is option (e).
Cellular respiration and photosynthesis are important parts of the carbon cycle. The carbon cycle is the pathways through which carbon is recycled in the biosphere. While cellular respiration releases carbon dioxide into the environment, photosynthesis pulls carbon dioxide out of the atmosphere. The exchange of carbon dioxide and oxygen during photosynthesis (Figure below) and cellular respiration worldwide helps to keep atmospheric oxygen and carbon dioxide at stable levels.
