The 1918 h1n1 influenza pandemic was the most severe pandemic in recent history. h1n1 spread through north america, europe, and asia in three waves during 1918-1919. in the u. s., it was first identified in military personnel in spring 1918. it is estimated that about 500 million people or one-third of the world’s population became infected with this virus. the number of deaths was estimated to be 50-100 million worldwide and 675,000 in the united states. mortality was high in people younger than 5 years old, 20-40 years old, and 65 years and older. the 1918 spread of h1n1 is considered a pandemic. what accounted for the spread of this virus to pandemic proportions? all but one would be a reason. a) public and private sanitation was not as advanced as it is today. b) although vaccinated, the h1n1 was resistant to the drug being used. c) antibiotics had not been developed yet to treat secondary symptoms. d) the flu spread rapidly throughout close living conditions, like in the military and in heavily populated cities.?

Photosynthesis converts solar energy into what type of energy?

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.

What is the average speed of a car that traveled 300.0 miles in 5.5 hours