Restriction enzymes: weld together fragments of dna attach to dna molecules at specific sites and cut both strands of dna at that place only cut rna molecules at specific sites and cut both strands of dna at that place are chemical machines that make parts of the cell membrane.

Elements and compounds are pure substances that cannot be broken down physically into a simpler substance. a physical change doesn’t break the bonds between atoms of a substance or form new ones. compounds can be broken down by a chemical change. a chemical change breaks chemical bonds and/or forms new ones between atoms of a substance. what simple substance would a compound break into? the basic elements that make it up! for example, if you passed a very strong electric current through water you’d break the chemical bonds in water and be left with oxygen and hydrogen. which of the following is an example of a chemical change? a separating water into different glasses b breaking frozen ice cubes with a hammer c running an electric current through water d boiling water to evaporate it on a stove

Which of the following are the functions of the skeletal system? blood cell production in soft marrow tissues and mineral reserves largest organ of the body for defense and support vitamin d production and pumping blood through vessels voluntary movement and contractile movement

Identify the terms using the following picture. principle of dominance item 1 can be described as the . item 2 can be described as the . the "p" represents from one parent.