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Question: questions note follow the counting rules of section d of...

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QUESTIONS NOTE: Follow the counting rules of section D of this exercise. 1. One hundred grams of cabbage is blended with a 250 ml water blank. Consecutive dilutions of 1:100 and 1:100 are made. From the last dilution, samples of 1.0 ml and 0.1 ml were plated in duplicate. The plates containing the 0.1 ml sample had colony counts of 60 and 70 respectively. What is the count per gram of the cabbage? 2. One gram of food is blended with a 9 ml water blank. Consecutive dilutions of 1:10 and 1:10are then made. Duplicate one ml portions from the last dilution are then plated. The plates are incubated, and the colony counts are determined to be 32 and 35. What is the count per gram of the food sample? 3. Two grams of food are blended with an 8 ml water blank. Consecutive dilutions of 1:100, 1:100, and 1:10 are then made. From the last dilution duplicate 0.1 ml portions are plated, and after incubation it is determined that the plate count average is 245. What is the count per gram of the food sample? 4. Sanitarians investigating a food poisoning outbreak could get only 4 grams of the suspected food. The sample was blended with 99 ml of water and five 1/10 additional dilutions were made. Duplicate one-tenth ml of each dilution were surface plated on Baird-Parker agar. After incubation the plates from the fifth dilution (dont forget the intial dilution) showed 240 and 242 typical Staphylococcus colonies. Express the result as the number of staphylococci per gram of food.5. Forty-six grams of a food sample were blended with 54 g and 1.0mlportions ofthe final dilution were plates. State the count in bacteria per gram of sample of water. Two successive dilutions of 1:100 tion, 93 and 99 colonies were counted on the duplicate were mad 6. A sample containing 1.6gpepper and 10 grams of water was heat shocked (heated at Roec the number of aerobic sporeforming bacteria. After rapidly cooling the sample, one ml was dilution consisting of 1:100 was made, and agar was added to each plate and, after incubation, an average of l17 colonies was reported. What is theoount per gram of pepper? 80°C for 10 min) to determine er ml of plate f1:100 was made, and 0.1 ml portions were dispensed to two petri dishes. Twenty mlo ml of whey were mixed with 100 ml of water, and three successive 1:10 dilutions were made. Two sets of duplicate pour plates were made containing 0.1 and 1.0 ml of the final dilution. The plates containing 0.1 ml of the sample have 50 and 54 colonies after incubation, while the plates containing 1.0 ml contained 550 colonies on each. What was the total count of whey sample (bacteria per ml)? 8. Thirty-two g of a food sample were blended with 68 g of water. technician prepared only one plate and accidentally added 1.1 ml instead of 1.0 ml to the plate. After incuba colonies were counted. State the count in bacteria per gram of sample. Two successive dilutions of 1:10 were made. The tion, 78 3 How many grams of chese must be added to a 9 ml water blank to give a one-to-two dilution? 10. In your own words describe what makes a representative sample

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