Question

1.) Which bacteria grew in the widest range of temperatures?

a.) P.fluorescens

b.) B. gloibporus

c.) B. stearothermophilus

d.) E. oli

2.) Which of the following bacteria gre best at the lowest osmotic pressure?

a.) S.ruber

b.) E. coli

c.) S. aureus

d.) V. costicola

3.) Which statement explains what aerobes use oxygen to do?

a.) to insulate themselves in anaerobic enviroments

b.) to prevent free radicals from reacting with DNA and other vital molecules

c.) to provide the alcohol group added to organic compounds in fermentation

d.) to oxidize organic compounds for the release of energy and/or as a terminal electron acceptor

Answer 1

1. Option C is correct.

Different species of bacteria are able to grow on different range of temperature, depends upon the body organization and family they belongs.

B. steriothermophilus are gram positive, rod shaped bacteria and they are able to grow on wide range of temperature from 25-70 degree Celsius. They are present in various habitates such as: soil, water, hotwater spring and can cause food spoilage.

P. Fluorescence are rod shaped gram negative bacteria. They grow on temperature range from 25-30 degree celsius.

B. gloibporus are round shaped, gram positive and spore forming bacteria and they grow on temperature range from 25-33 degree celsius.

E. coli are mesophilic bacteria( they grow on mid range of temperature) and they grow on temperature range from 25-40 degree celsius.

2. option c is correct

Osmotic pressure is a pressure generated by solute concentration present in solvent.

Lowest osmotic pressure is the minimum concentration of solute present in solution which prevents flow of solvent from outside via a semipermeable membrane.

S. aureus have capacity to grow on wide range of osmotic concentration while all other bacteria can grow on normal osmotic condition.

S. aureus have different kind of adaptation mechanism which provides them suitable condition to grow.

3.

Option d is correct.

In aerobs complex food material broken down into simple compounds and produces energy. Energy is produced in the chemical form ATP.

First of all complex sugar molecule like glucose broken down into pyruvate and then these molecules forms acetic acid which undergo Electron transport system. In the electron transport system a movement of electron occurs which leads to pumping of proton and generates ATP from ADP.

Aerobic organisms use oxygen as last electron acceptor in electron transport system. When oxygen is not present ETS can not proceeded and not able to generate ATP.