DNA sequence may be used to identify different species. Assuming that you can use PCR to generate products for sequencing, describe in detail an experiment that will allow you to determine which strain of Salmonella has caused the more recent outbreak.

what does it mean to be alive? all life has some common characteristics such as:

list some characteristics of life you observed by the water bear: list some observations about the water bear and why its apparently so successful in a variety of environments

10.) In complex eukaryotes, what relationships exist between these DNA elements?

a. Centromeres, tandemly repeated DNA and constitutive heterochromatin

b.Interphase chromosomes, mitotic chromosomes, nucleosomes, histones.

c. Supercoiling and chromatin

11.) Which of the following statements is true?

a. Histones are an example of a sequence-specific DNA-binding protein.

b. The majority of human DNA is not known to be useful to our cells.

c. Human females have 23 different chromosomes, whereas human males have 24.

d. Because nucleosomes play a key role in packaging DNA into chromosomes, they bind to the DNA molecule very tightly and, once they are assembled, they cannot be moved.

e. A nucleosome consists of DNA wrapped around eight histone proteins, plus a short segment of linker DNA.

f. Nucleosomes are found only in mitotic chromosomes.

g. Histone proteins have a high proportion of positively charged amino acids, which bind tightly to the negatively charged DNA backbone.

12.) Micrococcal nuclease (MNase) is an enzyme that non-specifically cuts exposed DNA in its phosphodiester backbone. Brief digestion of eukaryotic chromatin with micrococcal nuclease gives DNA fragments ~200 bp long. You repeat the experiment, but incubate the samples for a longer period of time. This longer digestion yields 146 bp fragments. Why? Explain, using a diagram of the packaging of DNA by histone proteins into the basic unit of chromatin.

A pH gradient exists between the internal and external surfaces of the inner mitochondrial membrane of 1.4 pH units, where the external side is more acidic.

a. If the membrane potential is 0.6 V (where the internal side is negative), what is the free energy change on transporting 1 mol of protons across the membrane from outside to inside at 298 K?

b. Under standard state conditions, how many protons must be transported to provide enough free energy for the synthesis of 1 mol of ATP?

What are the main types of glial cells, and what is the main function of each? Glia outnumber neurons in the brain, yet neurons tend to be the focus of studies. Why?

The father of Mr. Spock, first officer of the starship Enterprise, came from the planet Vulcan. Mr. Spock’s mother came from Earth. Pure-bred Vulcans like Mr. Spock’s father have pointed ears (P), no adrenal glands (A), and a right-sided heart (R) and are homozygous for all of these alleles. These Vulcan alleles are dominant over normal earthling alleles. These three genes are autosomal, and they are linked as shown in this map:

P__15 map units_________A_____20 map units________R

If Mr. Spock marries a woman from Earth, what is the likelihood (expressed as a percentage or as a decimal) that their children would:

a) have Vulcan traits for all three of these characteristics?

b) have Vulcan ears, earthling adrenal glands, and earthling heart?

c) have Vulcan ears, earthling adrenal glands, and Vulcan heart?

6.) In the 1952 Hershey-Chase experiment showed that DNA is the genetic material of bacteriophage. Explain where the protein labeled with 35S ended up and where the DNA labeled with 32P ended up after centrifugation in their experiment. a. Draw a diagram of the experiment in support of your explanation. b. Is it possible to do the reverse labeling? (protein labeled with 32P and DNA is labeled with 35S) Why or why not?

7.) For each base-pair set, state if the two pairs are distinguishable using the minor groove, the major groove, or both. a. G:C vs. C:G ________ b. A:T vs. G:C _________

c. A:T vs. T:A _________

8.) Ethidum bromide (EtBr) is a large flat, multiringed cation. Its flat shape allows it to insert itself between the stacked base pairs of double stranded (dsDNA). Because it fluoresces when exposed to UV light and because its fluorescence increases dramatically after intercalation, it is used as a stain to visualize DNA. When ethidium intercalates it causes the DNA to unwind by about 26 degrees, reducing the normal rotation per base pair, decreasing the twist (T) of the DNA.

a. What effect would this change have on the writhe (W) of the plasmid?

b. When EtBr is used to visualize a relaxed covalently closed circular plasmid by gel electrophoresis, what effect would this have on the migration of the plasmid?

Concisely, describe the particular features of Creighton’s and McClintock’s experiment that allowed them to prove Morgan’s hypothesis that coupling and repulsion results from the physical exchange of DNA between homologous chromosomes?

A spontaneous mutation occurs in one of the copies of MT-TK, a gene found in mitochondrial DNA. MT-TK generates a tRNA required to make proteins formitochondrial function.

a. How can this mutation become deleterious?

b. In which parent and in which cells must this spontaneous mutation occur for it to be inherited? (hint: what happens if the mutation occurs in the heart.)

3.) Describe, to the best of your ability the bond chemistry behind the following attributes of DNA:

a. the double-strandedness

b. the antiparallel nature of the two strands.

c. the twist of the ladder into a helix.

4.) Griffith discovered that S. pneumoniae caused pneumonia in mice. In his experiments, mice were injected with different strains of treated and untreated bacteria. For each of the following, indicate whether the mice lived or died and why.

a. Mice injected with heat-killed S (smooth) strain

b. Mice injected with living S (smooth) and heat-killed R (rough) strain

c. Mice injected with heat –killed S and living R

·       In one experiment Lederberg used Gal⁺ and Gal^– strains of E. coli. One half of a plate that contained medium with galactose as the only carbon source was inoculated with phages that came from lysed cells of the Gal⁺ strain. The other half of the plate was left uninoculated. A Gal^- strain was then placed on the entire plate. Numerous colonies appeared on the half of the plate inoculated with the phage, whereas only a few appeared on the half that was not inoculated with phage. Explain what happened using appropriate terminology.

Marine Biology Question- What is an "anthropogenic stressor"?

Marine Biology Question- what are "Nonconsumptive predator effects (or, more generally, non-consumptive effect, NCE)"?

84. ________ was the first to describe microorganisms, while ________ was the first person to see bacteria.

a. Antoni van Leeuwenhoek / Robert Hook

b. Antoni van Leeuwenhoek / Robert Koch

c. Robert Hooke / Antoni van Leeuwenhoek

d. Robert Koch / Antoni van Leeuwenhoek

85. Archaea and Bacteria are unified as prokaryotes in lacking ________ which Eukarya contain, such as golgi.

a. membranes

b. nuclei

c. membrane-enclosed organelles

d. nuclei and membrane-enclosed organelles

86. A bacterial species has a generation time of 20 minutes and is growing exponentially. If there are 10 cells initially how many cells are there after 80 minutes?

a. 30

b. 80

c. 160

d. 200

e. none of the above

87. The growth of almost all bacteria in the environment

a. is limited by cool temperatures

b. is limited by high pH

c. is limited by the availability of one or more nutrients

d. is unlimited because bacteria are metabolically versatile

88. According to Koch’s postulates a microorganism thought to cause a disease in one species of animal.

a. must be seen in samples of blood using a microscope

b. must be isolated in pure culture and then used to cause the same disease in healthy animals

c. must never be found in healthy individuals

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

89. Antoni van Leeuwenhoek developed and used

a. the first compound microscope

b. the first vaccine to prevent an infectious disease

c. a microscope with a single lens

d. pasteurization to prevent the spoilage of food

90. Gram positive bacteria

a. have a thick cell wall, which retains the crystal violet dye when cells are Gram stained

b. contain teichoic acid in their cell walls

c. appear purple when Gram stained

d. all the above e. none of the above

91. The cell envelope of Gram negative bacteria

a. includes a thick cell wall

b. includes both an inner and outer membrane

c. includes a peptidoglycan layer

d. always includes a capsule made of polysaccharides

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

92. 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

93. Regarding early life on Earth,

a. microbial life existed for hundreds of millions of years before plant and animal life

b. microbial life existed long before animals but has been around for about the same amount of time as plants

c. microbial life, plant life, and animal life all appeared at about the same time

d. it is impossible to determine which type of life first appeared.

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