Answer:
Ptolemy included epicycles in his orbits.
Explanation:
Ptolomy's model of the solar system was geocentric, where the sun, moon, planets, and stars all orbit the earth in perfectly circular orbits. The problem with perfectly circular orbit around the Earth is that they do not explain the occasional backward motion, or retrograde motion, of the planets.
The Greeks insisted that the motion of the planets be perfectly circular. Ptolemy modeled the planets making small circles around a point that orbited the Earth. These smaller circles were called epicycles, and they allowed the planets to move backward relative to the background stars.
Answer:
DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine.
Proper environmental sanitation and the use of insecticides will prevent the spread of dengue fever virus.
<h3>What is a disease vector?</h3>
A disease vector is an organism which transmits pathogens to other organism.
Aedes aegypti mosquito is the vector for dengue fever. It transmits mosquito through its bite, thus introducing the virus into the blood.
The use of insecticides and the proper sanitation will help prevent the transmission of diseases.
At home, use of insecticide-treated nets will help prevent the spread of dengue fever.
Therefore, proper environmental sanitation and the use of insecticides will prevent the spread of dengue fever virus.
Learn more about disease vectors at: brainly.com/question/1086343
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