Food web provides a better model of an ecosystem and model of many different consumers
        
             
        
        
        
Answer:
More than 7000 chemicals are present in tobacco smoke. 
Explanation: 
In these 7000 chemicals, 250 are harmful to the human body such as carbonmonoxide, ammonia and hydrogen cyanide etc. There are some chemicals that are found in tobacco smoke which causes cancer disease in human. About 69 chemicals out of 250 are present in tobacco smoke that causes cancer disease. So its consumption is dangerous for health. 
 
        
                    
             
        
        
        
The right answer is C
This process is called anaerobic respiration. It doesn't need dioxygen to occur (it can happen with or without O2).
Anaerobic respiration is a mechanism in which electrons pass through a chain of transporters whose final acceptor is a mineral substance other than oxygen, unlike aerobic respiration where the final acceptor is dioxygen. The final acceptor may be the nitrate ion (as in the case of Pseudomonas), carbon dioxyde or the sulfate ion.
Some bacteria (Pseudomonas) are able, anaerobically, to reduce nitrates to nitrites and then, depending on the case, to dinitrogen (with the enzyme Nitrate reductase A).
NO3- ==> NO2- ==> N2.
 
        
             
        
        
        
Answer: 21.5
Explanation: BMI is the value that is calculated for attaining the toatal fat in a body. 
Given units are,
Weight of individual=150 lbs(pounds)
Height of individual=70 inches 
BMI index formula in terms of pounds and inches is:-
BMI = (Weight in Pounds / (Height in inches) x (Height in inches)) x 703
BMI=(150 lbs/(70 inches)×(70 inches))×703
<u>BMI=21.5</u>
 
        
             
        
        
        
A reduction in volcanic activity and earthquakes. Which results in causing warmer surface temperatures because particles released by volcanoes have a cooling effect.