The gases that surround the earth make up the

cryosphere
hydrosphere
biosphere
atmosphere

Mike was adopted, and his biological family history is unknown. although he is healthy, he would like some understanding of his genetic makeup, including potential health risks and genes that he could pass on to his children. mike has heard about commercial laboratories that can compare segments of your dna to those of people with common hereditary diseases in order to give you some idea of how susceptible you are to the diseases. the results of these types of tests are highly inconclusive. if mike's dna showed that he shares similarities in a segment of dna with people who have a given disease, his chances of developing that disease or passing it on to his children may be slightly elevated, but they are not 100 percent. these tests can cost more than $2,500 and are not covered by many insurance companies. do you think that mike should undergo the genetic tests? explain your answer. what are the potential pros and cons of having such tests done? describe how the availability of these genetic tests might affect the frequency of genetic diseases in individuals and populations.

Is snow a type of precipitation? explain why or why not.

Rease is an enzyme used by plants to break down urea (a nitrogen-containing compound) into carbon dioxide and ammonia. urease urea > > > carbon dioxide and ammonia ammonia is broken down by plants into a nitrogen source plants need to grow. thus, plants could not use urea as a nitrogen source unless it was first converted to ammonia. in soybean plants there are two different kinds of urease, one produced in the seeds and the other produced in the leaves of the plant. three types of soybean plants were used in a set of experiments: normal soybeans and two mutant strains, one lacking the urease in the seeds only (strain 1) and one lacking urease in the leaves only (strain 2). experiment 1 separate areas in a field were planted with normal, strain 1, and strain 2 soybeans. all types of soybeans appeared to grow, flower, and produce seeds equally well. there were no externally detectable differences among the strains. experiment 2 small pieces of plant leaves of equal weight were obtained from each type of soybean plant and separately placed on media in culture dishes. tissue growing in this way will become an unorganized clump of cells referred to as callus. to provide a controlled nitrogen source, half the tissue samples of each type were placed on media containing urea, and the other half of the samples were placed on media containing ammonia. after 30 days, the weight gain for each of the callus samples was determined. results are shown in the table below.