Answer:
A. Cholecalciferol, or vitamin D3, is necessary for the normal absorption of calcium and phosphate ions. Vitamin D3 is made by cells in the epidermis due to exposure to sunlight. Without enough exposure to sunlight, the body won't produce enough vitamin D3
Explanation:
Hydroxyapetite is the organic mineral in the bone that maintain the mechanical strengthening of the bone, by interacting with collagen fibres. Calcium and Phosphate ions are the two major components of this bone materials. Generally 90%of bone is calcium , while 80% is phosphate. Phosphate stimulate growth of Oesteocytes. And the latter is important for bone mineralization. Together they maintain bone mineralization and maintenance,thereby preventing bone resorption.
Absorption of Ca and P. into the blood stream to reach the bones cells is conducted by Vit D. Dietary supply is not the only route through which Vit D get to the blood stream. Exposure of the skin to UVB rays of the early morning sunlight is another route.
Vitamin D plays major role in absorption of Ca and P in the body.
Vit. D is naturally synthesized in humans when the skin is exposed to early morning sunlight (UVB). It is usually produce in inactive forms,and undergoes hydroxylation( i.e addition of hydroxyl group -OH) in the liver to be biologically active .
Its active forms acts on the epithelial cells of the intestinal wall to facilitate calcium absorption into the blood stream to reach the bone cells .it also stimulate absorption of Phosphate.
Since these two minerals ensures, mechanical strength, prevention of bone resorption, there availability in the bone must be maintained by Vit, D supply from exposure to sunlight.
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Answer: b. it takes time for signals to travel all the way to the brain.
Reflex reaction is the instantaneous reaction of the body to the applied external stimuli. This mechanism is present in the body to make it possible to quickly react to situations without putting much effort into thinking and processing the nature of the stimuli. The reflex arc does not include the brain. This is because the brain has to receive signal from the sensory organs through sensory neurons, process it, and send a signal through the motor neuron to the muscles to generate a response. The whole process is time taking and lowers the reaction time of the organism, which can be dangerous in certain situations.
Answer: Option (D) is the correct answer.
Explanation:
A hypothesis is defined as an educated guess with the help of which an individual might predict what would happen in a certain experiment or situation.
When we evaluate some data with the help of analytical and reasoning approach then it is known as analyzing data.
Stating the problem means defining the problem so that others can also get to known the problem.
Therefore, we can conclude that when Jeremy is conducting an experiment and has just made an educated guess as to what will happen in the experiment then making a hypothesis is the step of the given scientific method.
Answer:
Electromagnetic waves have many different wavelengths and frequencies that span a range known as the electromagnetic spectrum. Light of different wavelengths produces different perceptions of color. The longest wavelengths produce the perception of red, while the shortest ones produce the perception of violet.
It can helps us to keep the human body healthy and continue to discover how to keep it healthy, and what keeps it healthy. The study of biology can lead to discovering how to prevent diseases. In the environment, if something is off, then people can use biology to see what is wrong and how to fix it.
