Penn Foster Biology Exam 1 Review | Cells, Atoms & Water Properties|Complete with A+ Graded Answers

Penn Foster Biology Exam 1 Review | Cells, Atoms & Water Properties|Complete with A+ Graded Answers _______ are the smallest units of life. Cells Which one of the following lists shows the correct order of biological organization? Population, community, ecosystem, biosphere A modification that makes organisms more suited to their environment is called a/an adaptation. The life-domain whose members live in very harsh environments, such as salt lakes and hot springs, is called Archaea. During a scientific experiment, the control group is identical to the experimental group in all areas except the variable being tested. The subatomic particle that carries a positive electrical charge is the proton. When an atom has two or more outer electron shells, the outer shell will be most stable if it contains eight electrons. This concept is called the octet rule. When two oxygen atoms join together, a _______ is formed. molecule The type of bond in which atoms share electrons to produce a completed outer shell is a/an _______ bond. covalent The polarity of water molecules causes them to be attracted to one another in what's called a _______ bond. hydrogen As the number of hydrogen ions in a solution increases, the pH of the solution decreases. During winter only the upper surface of a lake freezes, which allows for life to persist below the surface. Which of water's unique properties is responsible? Lower density as ice The most a