Respiratory system helps in breathing and it leads to exhalation of the gas carbon dioxide which is not required by the body. The integumentary system is the first line of defense and protects the body from invadig microbes, dust, and other harmful substances. The digestive system protects the body by enabling digestio of food and providing energy to sustain, further the toxic waste materials are also released during the process.
Two key characteristics of a good scientific investigation are hypothesis and observation of whatever organism your studying.
<span>Complete the sentence below by selecting the correct words from the drop-down menus.
There are three requirements for natural selection. The requirements are </span><span>✔ variationsimilarity</span><span>, <span>underpopulation✔ overpopulation</span><span>, and <span>✔ adaptationextinction</span><span>.</span></span></span>
