Which of the following statements is/are completely correct? Select one:
a. Crystal violet is considered a differential stain.
b. Sporulation occurs when there are plenty of nutrients and water available.
c. In a Gram stain, ethanol is used as the mordant.
d. Bacillus species are capable of undergoing sporulation.
e. Endospores are considered reproductive structure. f. Two of the above statements are correct.
Which of the following statements is/are completely correct? Select one:
a. Crystal violet is considered a differential stain.
b. Sporulation occurs when there are plenty of nutrients and water available.
c. In a Gram stain, ethanol is used as the mordant.
d. Bacillus species are capable of undergoing sporulation.
e. Endospores are considered reproductive structure. f. Two of the above statements are correct.
Related textbook solutions
Related questions
1.This week, you will be conducting Gram stains of bacteria.Which of the following statements are true? (Mark all thatapply)
Gram-negative bacteria do not stain purple because they do nottake-up crystal violet or iodine | ||
The peptidoglycan in the walls of Gram-positive bacteria bindsto the crystal violet stain more easily than walls of Gram-negativebacteria do | ||
Gram-positive bacteria have cell walls with a thickerpeptidoglycan layer than walls of Gram-negative bacteria | ||
Gram-negative bacteria do not stain purple, because their cellwall structure allows purple-colored iodine-dye complexes to washout of the cells more easily than the cell wall structure ofGram-positive bacteria does | ||
Gram-negative bacteria have an outer membrane (outside thepeptidoglycan layer in their wall) that Gram-positive bacterialack |
2.
What evidence is used to inform our understanding ofrelationships among species? (mark all that apply)
Biochemical similarities between existing species | ||
Fossils | ||
Morphological similarities between existing species (presence ofhair, backbones, etc.) | ||
DNA sequences and molecular clocks |
3.
For each of the groups of organisms below, indicate whether theybelong in (A.) Archaea, (B.) Bacteria, or (C.) Eukarya
|
4.
Select all true statements about the relative diversity ofdifferent groups of organisms from among the followingstatements:
There are more species of plants on Earth than species ofmolluscs | ||
There are more plant species on Earth than mammal species | ||
There are more species of plants on Earth than species offungi | ||
There are more species of fungi on Earth than mammal species | ||
There are more species of plants on Earth than species ofarthropods | ||
There are more flatworm species on Earth than mammal species |
I need help on this microbiology question:
Contrary to our favorite science fiction books and movies, the chances of us finding another planet with a civilization comparable to, or even more advanced than our own, seems highly unlikely. But, through your work as a microbiologist at NASA, you have been able to help change our views as to what forms of life we should be looking for on planets in our solar system and around neighboring stars. Instead of radio signals or errant transmissions, we have begun looking for planets that have environments similar to those capable of sustaining life as we know it here on Earth. To determine what we could find out there, you have begun studying different unique and atypical environments found here on Earth. Although the harsh conditions of hot springs or undersea sulfur vents seem incompatible with most forms of life, organisms known collectively as "extremophiles" have still managed to survive and adapt to these extreme conditions. You believe extremophiles may help you gain insight into the potential metabolic requirements, processes, and challenges of extraterrestrial life. Thus far in your search, you have identified some prokaryotic cells that have evolved to survive in the extreme conditions of sulfur vents on the sea floor. These vents are found at great depths, where the crushing pressure and lack of light and oxygen are prohibitive to many forms of life. Bacteria that are not considered extremophiles reside in most ecological niches on this planet. There are some common criteria for the environment that would sustain these bacteria. Availability of water, pH that lies between 5 and 9, temperatures that will remain steady and below boiling; these are some of the characteristics that bacteria will require in their environment if they are to succeed. But in the environment of the ocean floor vents, not only is the pH of the water very low, but also the water temperature is unusually high due to the geologic activity that fuels the vents. Organisms that are adapted to such harsh conditions have necessarily evolved enzymes able to function beyond average optima, as well as a chemosynthetic metabolism capable of using vent organic and inorganic compounds as energy sources.
Part A - Comparable Earth Environments to Be Found on Another Planet
You identify the prokaryotic cells you've found as a species of bacteria. These bacteria appear to be living off of nutrients and sulfur compounds released from the vents on the sea floor. Over time, the bacteria must have evolved extreme metabolic and enzymatic capabilities to allow them to tolerate and even benefit from the extreme depths, the lack of oxygen, the low pH of the surrounding waters, high temperatures due to volcanic releases, and the unique nutrient source of the vents.
Choose the characteristics and their impact on enzyme activity that are not correct from the following statements. (more than one may be chosen)
| Archaea are able to tolerate highly acidic pH environments and have proteins that will not denature in the low-pH environments that the bacteria are found in. |
| Archaea are able to colonize water that is at or above the boiling temperature due to high levels of disulfide bridges that maintain the three-dimensional structure of the enzyme. |
| Archaea are only able to survive exceedingly well at high temperatures due to the amount of activation energy required by their enzymes. |
| Archaea are able to grow in extremely shady or low-light conditions that allow for optimal enzyme activity. |
