Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?

#Question id: 1986

#Section 2: General Biology

The following events occur when a mammalian immune system first encounters a pathogen. Which shows the correct sequence in which they occur?

I.   Pathogen is destroyed.

II.  Lymphocytes secrete antibodies.

III. Antigenic determinants from pathogen bind to antigen receptors on lymphocytes.

 IV.  Lymphocytes specific to antigenic determinants from pathogen become numerous.

V.   Only memory cells remain.

#Question id: 4147

#Section 3: Genetics, Cellular and Molecular Biology

Which one of the following antibiotics does not function by interfering with the translational process?

#Question id: 3532

#Section 3: Genetics, Cellular and Molecular Biology

In a plant species, flower color purple is dominant over white. One such purple-flowered plant upon selfing produced 35 viable plants, of which 9 were white flowered and the rest were purple flowered. What fraction of these purple-flowered progeny is expected to be pure purple-flowered line?

#Question id: 14566

#Section 2: General Biology

concentration 8.0 x 10⁷ cells/ml?

#Question id: 1893

#Section 2: General Biology

The injection of tuberculin into the skin of a sensitized individual elicits: