A Petri dish (alternatively known as a Petri plate or cell-culture dish) is a shallow transparent lidded dish that biologists use to culture cells, such as bacteria, fungi or small mosses. The container is named after its inventor, German bacteriologist Julius Richard Petri. It is the most common type of culture plate.
There were A adults, Sm male students, and Sf female students.
<span> </span>
<span>Sm = 1 + 7A </span>
<span>Sf = Sm/2 </span>
<span>A + Sm + Sf = 82 </span>
<span>A + (1 + 7A) + (1 + 7A)/2 = 82 </span>
<span>2A + 2 + 14A + 1 + 7A = 164 </span>
<span>23A + 3 = 164 </span>
<span>23A = 141 </span>
<span>A = 7 </span>
<span>The number of male students is 50. </span>
<span>The number of female students is 25.</span>
DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). <span>DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule. Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix. The structure of the double helix is somewhat like a ladder, with the base pairs forming the ladder’s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.</span>
C.All living things are made of the same elements
Human influence ecosystem by chopping down forests,and cars burning off greenhouse gases.Humans can effect the ecosystem in a negative way ,by pollution, waste dumping, over hunting of animals,over fishing,industrial gases,energy use and not using
