HW 1-3

Question 1

During the 4-billion-year history of life on earth, all organisms were microbial during the first:
1)500 million years
2)1 billion years
3)2 billion years
4)3 billion years
5)3.75 billion years

Answer 1

3 billion years

Question 2

A Winogradsky column provides a favorable growing environment for which of the following types of microorganisms?
1)Photosynthetic aerobes
2)Nitrogen fixing chemolithotrophs
3)Anaerobic microbes that require limited or no light
4)Chemolithoautotrophs
5)All of the above

Answer 2

All of the above

Question 3

Koch

Answer 3

Development of pure culture techniques

Question 4

Pasteur

Answer 4

Disproving Spontaneous Generation

Question 5

Lister

Answer 5

Promoted disinfection of medical environments

Question 6

van Leeuwenhoek

Answer 6

Producing a microscope to allow observation of bacteria

Question 7

The organisms that produces most of the oxygen in the atmosphere of the early earth are called ____

Answer 7

Cyanobacteria

Question 8

What compound is most commonly used to solidify the growth medium in Petri dishes?

Answer 8

Agar

Question 9

Explain two important reasons why the Cow Pox virus was able to work as an effective vaccine for Small Pox.

Answer 9

One reason was that the cow pox virus, even though it was a mild disease, was very similar to the small pox virus. Another reason was the immune response to cowpox gave protection against smallpox.

Question 10

The appearance of Gram-negative bacteria after decolorization with the decolorizing agent (alcohol) in the Gram stain is:
1)Purple
2)Red/orange
3)Colorless
4)Brown

Answer 10

Colorless

Question 11

Fluorescence

Answer 11

Allows localization of specific cell proteins

Question 12

Phase-contrast

Answer 12

Allows visualization of live cells

Question 13

Transmission electron

Answer 13

Requires staining with heavy metals

Question 14

Dark field

Answer 14

Only light diffracted by th especimen is visualized

Question 15

The total magnification of an image by a microscope is the product of the strength of the _____ and the _____

Answer 15

Objective lens and the Ocular lens

Question 16

Two types of eukaryotic cell organelles that arose via endosymbiosis are:

Answer 16

Mitochondria and Chloroplasts

Question 17

Photoautotrophs obtain their energy from _____ and their carbon source from _____

Answer 17

light, carbon dioxide

Question 18

Describe three reasons that Woese chose rRNA as a molecule on which to base a molecular approach to phylogeny.

Answer 18

rRNA is an ancient molecule that all cells have. rRNA has changed very slowly over evolutionary time. rRNA is easily sequenced.

Question 19

NAD+ can serve as a carrier of____
1)electrons
2)protons
3)electrons and protons
4)electrons and neutrons
5)iron and sulfer

Answer 19

electrons and protons

Question 20

Prosthetic group

Answer 20

A chemical reactive structure covalently attached to an enzyme

Question 21

Cytochrome

Answer 21

A protein that accepts and donates electrons

Question 22

Coenzyme

Answer 22

A chemical reactive structure that transiently associates with an enzyme

Question 23

Anabolism

Answer 23

The assembly of new cellular building blocks

Question 24

When ___ -trophs carry out respiration, they transfer ___ from inorganic compounds to terminal electron acceptors.

Answer 24

chemolitho, electrons

Question 25

During aerobic respiration, ___ is the terminal electron acceptor, and theis acceptor is converted to the product: ___

Answer 25

oxygen, water

Question 26

In Oxidative phosphorylation, energy from the ____ is used by the enzyme ____ to produce ATP.

Answer 26

proton gradient, ATP synthase

Question 27

Describe how fermentation and anaerobic respiration achieve one goal in common for the cell. Then describe why anaerobic respiration might be more beneficial for the cell.

Answer 27

Both fermentation and anaerobic respiration result in recycling/oxidation of reduced coenzymes. Anaerobic respiration produces energy (a proton-motive force and/or ATP) while fermentation does not.