A timeline of important discoveries about DNA is shown below. These discoveries have
contributed to our current knowledge about DNA.
1669
DNA is discovered.
1919
Base, sugar, and phosphate
structure is identified.
1944
1950
DNA identified as basis
of heredity.
Rules of nucleotide base
pairing established.
X-ray diffraction captures
DNA images
DNA structure is determined
1951
1953
Which statement best summarizes the development of knowledge of DNA over time?
Ideas about DNA have remained unchanged over time.
Scientists gained more knowledge about DNA as new evidence became available.
Changes in ideas about DNA are based on opinion.
Past knowledge of DNA was discarded as each new discovery was made.

(science)study the following ocean currents map. an ocean currents map is shown. on the map the locations for san diego, california and savannah, georgia are marked. there is a looping current from the north past san diego and a looping current from the south near savannah which statement is most likely correct about the average temperatures in san diego, california as compared to savannah, georgia? it is higher in savannah because of the cool ocean currents from the south. it is higher in savannah because of the warm ocean currents from the north. it is lower in san diego because of the warm ocean currents from the south. it is lower in san diego because of the cool ocean currents from the north.

As part of an industrial process, air as an ideal gas at 10 bar, 400k expands at steady state through a valve to a pressure of 4 bar. the mass flow rate of air is 0.5 kg/s. the air then passes through a heat exchanger where it is cooled to a temperature of 295k with negligible change in pressure. the valve can be modeled as a throttling process, and kinetic and potential energy effects can be neglected. (a) for a control volume enclosing the valve and heat exchanger and enough of the local surroundings that the heat transfer occurs at the ambient temperature of 295 k, determine the rate of entropy production, in kw/k. (b) if the expansion valve were replaced by an adiabatic turbine operating isentropically, what would be the entropy production? compare the results of parts (a) and (b) and discuss.

How are series and parallel circuits simililar? both have multiple paths for electrons to travel. both require resistors in their circuits. both require a switch to complete the circuit. both have at least one path for electrons to travel.