Question

94. The structure that confers structural strength on bacterial cells is known as the

a. cytoplasmic membrane

b. cell wall

c. ribosome

d. cytoplasm

95. Archaea and Bacteria are unified as prokaryotes in lacking ______________

a. membranes

b. nuclei

c. membrane-enclosed organelles

d. nuclei and membrane-enclosed organelles

96. When a bacterial culture contains only one type of organism, it is called a ______________.

a. mixed culture

b. liquid culture

c. environmental culture

d. pure culture

97. Prokaryotes and eukaryotes

a. have the same kinds of metabolic pathways, but little else in common

b. have nothing in common

c. have many things in common because they share a common ancestor

d. are identical to each other

98. Which of the following statements is true?

a. peptidoglycan is comprised of cross-linked fatty acids

b. the cell walls of most bacteria are composed of peptidoglycan

c. Gram-negative bacteria have a relatively thick layer of peptidoglycan

d. peptidoglycan is found mainly in the cell walls of fungi, algae and plants

e. answers (a) and (b) are both correct

99. The cell membrane of bacteria

a. is semi-permeable.

b. is usually a lipid bilayer

c. prevents cell lysis due to high intracellular osmotic pressure

d. answers (a) and (b) are correct

e. answers (a) and (c) are correct

100. A bacterial species has a generation time of 15 minutes and is growing exponentially. If there are 2 cells initially how many cells are there after 90 minutes?

a. 256

b. 128

c. 64

d. 32

e. none of the above

101. Most bacterial cells reproduce by

a. the budding of daughter cells from a mother cell

b. forming spores that later germinate

c. binary fission

d. production of gametes and sexual reproduction  

102. Which of these are routinely used to obtain a pure culture of bacteria?

a. swan necked flasks

b. agar streak plates

c. dilution plates

d. microscopes

103. The cells of all species of Bacteria and Archaea are very small, and:

a. must be stained before they can be seen using light microscopy

b. can only be seen using electron microscopy

c. can only be seen if they are first Gram stained

d. none of the above

104. Prokaryotes evolved early on in the history of the Earth:

a. so their physiology has little in common with Eukaryotes

b. so many aspects of their physiology also occur in Eukaryotes, which evolved much later in in the history of the Earth

c. and Eukaryotes evolved independently at a much later time in the history of the Earth

d. at about the same time that Eukaryotes first appeared on Earth

Answer 1

94) b cell wall provides structural strength to the bacteria.

95) d- nuclei and membrane bound organelles are absent in both of these.

96) d) pure culture.

97) c- they have many things in common because they share a common ancestors.

98) b- cell wall of most bacteria is composed of peptidoglycan

99) d- both a and b are correct. It is semipermeable and usually a lipid bilayer.

100) b-128

Formula used is

2^ (no. Of times the cell divides) x initial number of bacteria

In 90 minutes the cells will divide 6 times

So 2^6 x 2 = 64 x2 = 128

101) c- they reproduce by binary fision

102) b- agar streak plates are mostly used to obtain a pure culture of bacteria