In Drosophila, the genes b, c, and sp are linked and in the order given, the distances being b-c = 30 m. u. and c-sp = 20 m. u. These intervals exhibit 90% interference. How many double crossovers would be recovered in a three-point cross involving b, c, and sp out of 1000 progeny?

Salmonella typhimurium is a food-borne bacterial pathogen that can cause severe gastrointestinal disease. salmonella is often phagocytosed by macrophages that normally destroy bacterial pathogens, but this bacterium is somehow able to prevent the complete maturation of phagolysosomes. salmonella is able to tolerate the low ph of phagolysosomes, and in fact responds to the drop in ph by secreting toxins that interfere with other cellular responses. which of the following differences would you expect to contribute to the survival of a bacterium within an salmonella-containing phagosome, compared to a healthy phagolysosome? decreased activity of acid hydrolases increased activity of acid hydrolases decreased import of h+ ions increased import of h+ ions my guess is decreased activity of acid hydrolases but i'm not sure.

Which statement about the immune system is false? a. lymphocytes reduce inflammation, b. b cells remember specific pathogens. c. most white blood cells kill bacteria d. white blood cells are made in lymph nodes.

How does deforestation affect the water cycle? a. it increases the amount of runoff b.it increases the amount of percolation c. it increases the amount of transpiration d. it increases the amount of precipitationa it increases the amount of runoff