1. In the 1950s when Watson and Crick were working on their model of DNA, many scientists did not think that DNA carried the genetic code. What was the other type of molecule that some scientists thought might carry genetic information? *

Proteins

Explanation:

Since proteins were made up of 20 different types of amino acids and DNA was only four A,G,C and T many scientists thought that these were most likely to be carrying information. In addition to amino acids being in so many varieties they were also of different charges and shapes as well. It was believed that the amount of information that can be held in these 20 amino acids are much greater than that that can be held in just four bases.

primary succession begins with a bare rock and ends with a forest secondary succession begins after a natural disaster where there is a temporary setback after a forest fire or local destruction, but the surrounding area can fill in

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.