The first colorimeter is precise, but it is not accurate. It seems to have a zero error of -5.
We can conclude its precision because the readings are closely grouped, but its lack of accuracy is due to its variation from the actual value. Moreover, the variation is consistently of 5 points lower than the actual value, so its zero error may be -5.
The second colorimeter may be referred to as being accurate.
<span>Lay the frog on its back, spread out its limbs, and pin them to the tray. Use forceps to lift the skin between the hind legs and make a small incision with a scalpel. Continue the cut up the center of the frog's body with scissors, being careful to cut through the skin only. Use forceps to hold the skin away from the muscle while you cut, if necessary. Make horizontal incisions just above the legs and just below the arms, then fold the resulting flaps back and pin them. (You may need to use a scalpel to help separate the skin from the muscle underneath as you fold it back.)Repeat the incisions as before, this time cutting through the muscle layer to a point just below the arms. Lift the muscle with the forceps to prevent cutting the organs underneath.When you reach the area just below the arms, turn your scissors and make horizontal cuts through the hard sternum. Repeat the horizontal cuts just above the arms, and then remove the bony strips entirely. Pin the remaining muscle flaps back, just as with the skin.<span>Look into the body cavity. The yellow finger-like projections on the sides are the fat bodies. It may be necessary to remove some of these in order to see the organs clearly. Likewise, a female specimen may have well-developed eggs filling the body cavity and obscuring the organs. Remove them as necessary.</span></span>
Snakes can live up to 9 years. They slither up to 18 mph. Snakes are reptiles that are elongated, limbless, and carnivorous. Another interesting thing about snakes is that they don’t have eyelids. The last fact is that snakes can open there mouths up to 150 degrees so they can swallow there prey.
Answer: By studying the fossil record we can tell how long life has existed on Earth, and how different plants and animals are related to each other. Often we can work out how and where they lived, and use this information to find out about ancient environments. Fossils can tell us a lot about the past.
