<u>Answer</u>:       D. calcium chloride 
<em>Calcium chloride molecules can be ruled out as the mystery molecule</em>
<u>Explanation:</u>
<em>Artificial membranes are also called as the synthetic membranes.</em> It is created synthetically for the <em>special separation purpose in the laboratory. </em>
It is used to separate large molecules like <em>solid particles and big biological molecules like protein, DNA. </em>
They are produced from organic materials. <em>Calcium chloride contains the chloride ion and calcium ion,</em> as the chloride ion easily passes the artificial membrane so we can term <em>calcium chloride as the mystery membrane that passes the artificial membrane easily.</em>
  
        
             
        
        
        
Carbon cycle refers to an array of procedures by which the compounds of carbon are interconverted in the environment, comprising the inclusion of carbon dioxide into living tissue by the process of photosynthesis and then getting back into the atmosphere via respiration, the burning of fossil fuels, and the decomposition of dead organisms.  
The following are the steps that illustrate how the carbon cycle functions:  
1. Carbon enters the atmosphere as carbon dioxide from combustion and respiration.  
2. The absorption of carbon dioxide takes place by the producers to manufacture glucose in photosynthesis.  
3. The animals feed on the plant passing the carbon components through the food chain. The majority of the consumed carbon is exhaled in the form of CO2, which was produced at the time of aerobic respiration. The plants and animals die eventually.  
4. The dead plants and animals get dissociated by the dead organisms and return the carbon present in their bodies back to the atmosphere as CO2 by the process of respiration. In certain occasions, the dead plant and animals get converted into fossil fuel, which is available in future for combustion.  
 
        
             
        
        
        
So we can look back and see how much we have accomplished in the year with the models
        
             
        
        
        
Answer:
This question lacks options, options are:
A) cerebral cortex.
B) basal nuclei.
C) sensory pathways.
D) motor pathways.
E) All of the answers are correct.
The correct answer is E.
Explanation:
The cerebral cortex processes and filters its information before passing the most relevant aspects to other regions of the brain. Some of these brain regions, in turn, send information back to the cortex. These loops, known as 'feedback systems', are considered essential for the functioning of cortical networks and their adaptation to new sensory information. Neural circuits must first assess the importance of incoming sensory information and then refine how it is processed in the future. Positive feedback, triggered with the purpose of amplifying the response to the initial stimulus, can be compared to a chain reaction or a vicious circle. Few are the functions regulated by this mechanism; rather it is triggered in pathological situations. It is the system by means of which the organism very rarely regulates any of the bodily functions under normal conditions, making the initial stimulus to be maintained and even increased. This type of mechanism is predominantly present in pathological situations: Its constitutive elements are: stimulus, receptor, afferent pathway, integrating center, efferent pathway, effector and response. The response does not have the ability to satisfy the initial stimulus.
 
        
             
        
        
        
Answer:
Circulatory system
Explanation:
From the right atrium through the tricuspid valve to the right ventricle through the pulmonary sigmoid valve to the pulmonary trunk to the right and left lungs to the capillary beds of the pulmonary veins to the left atrium to the left ventricle of the heart through the mitral valve, to the aorta through the aortic semilunar valve, to the whole body, to the systemic arteries, to the capillaries of the body tissues, to the systemic veins, to the superior cava vein and inferior cava vein, which enter the right atrium of the heart.