Which molecule is needed for photosynthesis to occur? glucose

oxygen

carbon dioxide

nitrogen

Legumes, a type of plant, require rhizobia, a type of soil bacteria, to survive since these organisms fix nitrogen during photosynthesis. rhizobia use the legumes for food. what would most likely happen to the legume population if rhizobia suddenly became extinct?

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.

Recently, crops of vegetables such as lettuce and green onions have been contaminated, while they are still on the farm, with bacteria that cause food poisoning. how will science influence the way the government responds to prevent an increase in food-borne diseases? because science has shown that lettuce and green onions are not nutritionally valuable, the government may pass laws that ban the sale of lettuce and green onions. because science has shown that there is no way to prevent bacterial contamination, the government may pass laws that punish businesses that buy lettuce and green onions. because science has shown that the washing of hands prevent the spread of infectious diseases among people, the government may pass laws that require hand washing by everyone who handles food. because science has shown there are ways to find the source of the contamination, the government may pass laws that require farm practices that reduce the contamination of lettuce and green onions.