Albert Schatz Alexander Fleming
Alice Catherine Evans
Annie Chang
Antonie Van Leeuwenhoek
Carl Woese
Carlo Urbani
Carlos Juan Finlay
Carmen Sanchez
Charles Henry Nicolle
Claire Fraser
Dmitri Ivanowski
Edward Jenner
Elizabeth Bugie
Ferdinand J. Cohn
Fredrick Sanger
George Hirst
Giralamo Fracostoro
Gregory C. B. van Neil
Hans Christian J. Gram
Harold Amos
Hattie Alexander
Howard Ricketts
Ignaz Semmelweis
Ilya Ilich Metchnikoff
Jennifer Doudna
John Snow
John Tyndall
Joseph Lister
Julius Richard Petri
Kary Mullis
Kiyoshi Shiga
Louis Pasteur
Margret Pittman
Martha Chase
Martinus Beijerinck
Max Theiler
Paul Ehrlich
Rebecca Craighill Lancefield
Robert Gallo
Ronald Ross
Ruth Ella Moore
Salvador Luria
Selman Waksman
Sergei Winogradsky
Shibasaburo Kitasato
Stanley Cohen
Thomas Brock
Walter Reed
Wendell Stanley
William Augustus Hinton
Ernest Everett Just
in chronological order?

In the context of the neural impulse, which of the following is true about the depolarization of neuron membranes?

Considering the yellow and green pea color phenotypes studied by gregor mendel: a. what is the biochemical function of the protein that is specified by the gene responsible for the pea color phenotype? (1 point) b. a null allele of a gene is an allele that does not specify (or encode) any of the biochemical function that the gene normally provides (in other words, either no protein at all or only non-functional protein is produced from it). of the two alleles, y and y, which is more likely to be a null allele? (1 point) c. in terms of the underlying biochemistry, why is the y allele dominant to the y allele? (2 points) d. why are peas that are yy homozygotes green? (1 point) e. the amount of protein produced from a gene is roughly proportional to the number of functional copies of the gene carried by a cell or individual. what do the phenotypes of yy homozygotes, yy heterozygotes, and yy homozygotes tell us about the amount of sgr enzyme needed to produce a yellow color? explain your reasoning. (2 points)

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.