Question

Question 4 "A culture of 10 bacteria of Escherichia coli has a generation time of 30 minutes at 35 degrees Celsius. After Shours at this temperature, how many bacteria would you expect to 10,240 50 "1.000 320 10,000,000,000

Answer 1

ANS.4 (A)

Generation time of 1o Bacteria z 3 0min so in I Hours it reproduce 2 times and in 5 Hours = 582 = 10 times every time bacteria reproduce it get double So, st ! Jigme - Box 2 2 20 2 time - 20x2 = 40 3' time = 40x2 = 80 4th time 80x2 = 160 sth 16042 = 320 6th time - 320x2=640 J time - 640x2=1280 & time - 1280x2 +2560 gth time - 256082=5120 10"time - 5120X2=30240

ANS.5 (A) reducing medium

Media for growth of anaerobic bacteria: Anaerobic bacteria require absence of oxygen to grow, hence they must be placed in a special medium called a reducing medium. These media contain ingredients, such as sodium thioglycolate, that chemicallycombine with dissolved oxygen and deplete the oxygen in the culture medium

These are six Medias use for aerobes culture: (1) Basal media, (2) Enriched media, (3) Selective media, (4) Indicator media, (5) Transport media, and (6) Storage media.

ANS.6 (A)

An indirect way of estimating bacterial numbers is measuring the metabolic activity of the population (for example, acid production or oxygen consumption). For filamentous organisms such as fungi and molds, measuring dry weight is a convenient method of growth measurement.