Coal contains sulfur and other elements, like dangerous metals (mercury, leads, and arsenic) that get into the air when coal is burned. Burning coal releases particulates and cause an increase in air pollution, it also emits the amount of CO2 (carbon dioxide) in the atmosphere
Firstly the question is incomplete as an option is not there.
Why do the number of organisms in a group change from the first step to the last step of a dichotomous key?
a. The number of organisms decreases because the number of common characteristics of the organisms in a group increases.
b. The number of organisms increases because the number of common characteristics of the organisms in a group increases.
c. The number of organisms is cut in half because the number of common characteristics of the organisms in a group decreases by half in the last step.
d. The number of organisms stays the same because the number of common characteristics of the organisms in a group decreases by half in the last step.
The correct answer is B. The number of organisms increases because the number of common characteristics of the organisms in a group increases.
The most common key for the identification of organisms is a dichotomous key, the number of organisms in a group change from the first step to the last step of a dichotomous key as the no. of organisms increases and forms several groups of species and genus.
<h3>What is the use of the dichotomous key?</h3>
The use of dichotomous keys are :
- contrasting characters
- dividing organisms
- eliminating .
Hence concluded that the dichotomous key has a number of organisms increases because the number of common characteristics of the organisms in a group increases.
To learn more about dichotomous keys refer to the link :
brainly.com/question/1281957
