Lecture 9: Prokaryotes Pt 1

Question 1

What are the 3 monophyletic groups on the tree of life known as? What are they?

Answer 1

The three domains
1. Bacteria
2. Archaea
3. Eukaryotes

Question 2

What two domains are considered as prokaryotes?
Are these monophyletic Groups?

Answer 2

Prokaryotes and Archaea
No, they are not monophyletic groups

Question 3

What are the 6 things that make prokaryotes so diverse and interesting?

Answer 3

1. They represent 2/3 domains of life
2. Most prokaryotes are single celled organisms (although some are simple multi-celled organisms)
   3.They are the most abundant organisms on Earth
3. Prokaryotes are centrally important to all kinds of biological functions
4. Prokaryotes contribute to human illness and human health
5. Learning Cool things such as prokaryotes in your gut can lead to your mood and mental state

Question 4

How, who, and when was archaea discovered?

Answer 4

Around 1960-1970, Carl Woese began making molecular phylogenies to decipher the tree of Life and found there are differences between bacteria and archaea

Question 5

How is it possible humans contain more prokaryotes than eukaryotes?

Answer 5

Prokaryotes resides in our mouth (700), intestines(1000), skin, etc.
Prokaryotes weigh 3 pounds total in your body

Question 6

What diseases are examples of bacterial pathogens?

Answer 6

Strept throat, dirrahea, black plague, gonorrhea

Question 7

What are the 5 ways to catalog prokaryote diversity?

Answer 7

1. Enrichment culture
2. DNA sequence
3. Shape (to distinguish prokaryotes)
4. The Gram Stain (composition of cell wall and membrane)
5. Modes of Nutrition

Question 8

How must a bacteria be studied? How is this done?

Answer 8

Bacteria must be cultured or grown in the lab. The Classic approach is to try to use growing conditions to coax the bacteria to grow. (only a small amount of bacteria is grown in lab)

Question 9

How has DNA sequencing resulted in the explosion of our knowledge of prokaryotes?

Answer 9

One isolates Dna from an environmental sample (soil, water, gut, nose, etc) and then sequences the sample of the entire DNA or rDNA sequence.
Because each prokaryotic species has a DNA sequence that reflects phylogenic history one can determine the amount and relative amount of each species.

Question 10

What are the different shapes of prokaryotes?

Answer 10

Spherical-coccus
Rod shaped-bacilli
helical
Treponema pallidium- corkscrew shape

Question 11

How does the corkscrew shape of Treponema Palladium cause syphillis?

Answer 11

The bacterium screws it’s way into slight breaks in the skin and multiplies prolifically