Biomes on earth have exhibited changes throughout history that have been caused by a variety of factors. over the past 50 years, the amount of tropical rainforest acreage found throughout the world has decreased from 14.8 billion acres to 8.6 billion acres due to deforestation. what factor is likely most responsible for the changes observed in the world’s rainforests?

In which of the following ways is the function of the surface of a microsphere similar to the function of an actual cell membrane? a. both make it possible for the conditions in the interior to be different from the conditions outside. b. both provide a barrier that keeps water from flowing across it so the interior remains dry. c. both separate the rna that forms in the interior from any rna that might form in the environment. d. both can actively move molecules into the interior or out into the surrounding environment.

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.

2polnis which of the following is an advantage of an in vitro experiment?me