Topic 9- Bacteria and archaea

Question 1

Prokaryotes

Answer 1

Pro (before in Greek) and karyon (nucleau in Greek)
-The group of prokaryotes is considered a paraphyletic group
-group of taxa that includes a common ancestor and some of its descendants

Question 2

Archea are not…

Answer 2

Bacteria

Question 3

Prokaryotes- Plasma membrane

Answer 3

constitues a selective barrier with the environment

Question 4

Prokaryotes- Cytoplasm

Answer 4

Content of the cell within the plasma membrane and is only made of the cytosol

Question 5

Prokaryotes- cytosol

Answer 5

internal fluid containing organic molecules, proteins, metabolic waste, etc

Question 6

Prokaryotes- Fimbriae

Answer 6

short appendages helping bacteria adhere to the substrate or to toher cells

Question 7

Prokaryotes- Capsule

Answer 7

dense layer of polysaccharide or protein surrounding the cell wall
- protects the cell and allows the bacteria to adhere to substrate or cells

Question 8

Prokaryote- Flagellum

Answer 8

Long cellular appendage specialized for locomotion

Question 9

Gram classification

Answer 9

Bacteria can be classed according to the structure of their cell wall into Gram (+) and Gram (-).
-Gram negative bacteria tend to be more resistant to antibiotic (the outer membrane blocks water soluble antibiotics)

Question 10

Nutritional requirements- Microbiome

Answer 10

community of microorganisms that live on and in the human body

Question 11

Nutritional requirements- Commensalism

Answer 11

symbiotic relationship in which one organism benefits but the other is niether helped nor harms

Question 12

Role of prokaryotes in the biosphere- Food webs depend on primary producers for two things:

Answer 12

1. Absorbing energy from outside the ecosystem (sunlight)
2. Assimiltaing minerals into biomass, which is passed on to subsequent trophic levels.

Question 13

Prokaryotes plan a very important role in ecosystems by increasing…

Answer 13

the availibity of nutrients for plants

Question 14

Asexual reproduction- Reproduction by binary fission

Answer 14

Doubling in size and simple division in half

Question 15

Asexual reproduction- The phases

Answer 15

1. Lag phase: synthesis of components required for growth
2. Log phase: rapid growth through cell divisions by a factor of 2n
3. Stationary phase: the population stops to grow (lack of nutrients, oxygen, metabolic waste accumulation, etc), activation of stress response
4. Death phase: exponential loss of viability due to lack of nutrients, oxygen or prolonged exposure to waste

Question 16

Resistant to antibiotics-Antibiotic

Answer 16

molecule that kills or inhibits the growth of bacteria.
-Bacteria can evolve resistance to antibiotics through genetic variation, heritability and selection

Question 17

Conjugation

Answer 17

Strains of bacteria from the same species can donate DNA through conjugation

Question 18

Transduction

Answer 18

Bacteria can also exchange DNA through a virus called bacteriophage ( a virus that infects bateria)

Question 19

Transformation

Answer 19

Bacteria can liberate their DNA (ex. after the cell death) which can be taken up by another bacteria directly from the extracellular environment