Lecture 9: Microbial Population Ecology

Question 1

Biological Species Concept

Answer 1

members of a population that interbreed and produce fertile offspring that is based on sexual reproduction

• DOES NOT APPLY TO MICROBES (asexual production)

Question 2

Ecological Species Concept

Answer 2

set of individuals that are identical in terms of ecology

Question 3

What is the most common OTU definition used to describe microbial species?

Answer 3

97% 16S rRNA sequence identity

Question 4

Genetics Species Concept

Answer 4

genetic isolation
70% DNA-DNA hybridization of genomes
97% 16S rRNA similarity

Question 5

Horizontal Gene Transfer

Answer 5

• makes hard to categorize species
• can replace existing gene copies
• can introduce whole new functions

Question 6

Core genome

Answer 6

gene set of an organism that is commonly shared by vast majority of speciesA

Question 7

Accessory Genome

Answer 7

mobile elements of genome that is shared with one or more strains

Question 8

Niche

Answer 8

the role an organism plays in a community

Question 8

TRUE OR FALSE: modern eukaryote genomes are chimeric

Answer 8

TRUE

Question 9

Species niche

Answer 9

encompasses both the physical and environmental conditions it requires ( like temperature or terrain) and the interactions it has with other species ( like predation or competition)E

Question 10

Ecological Niche Concept

Answer 10

the range of conditions under which an organism can survive and reproduce ( abiotic vs biotic factors)

Question 11

Fundamental Niche

Answer 11

full range of conditions that an organism could use

Question 12

Realized Niche

Answer 12

the portion of the fundamental niche actually occupied by that species

Question 13

Niche overlap

Answer 13

indicates intensity of competition for resources

Question 14

Which of the following determine the “size” of a populations niche?

Answer 14

A. tolerance for abiotic conditions
B. competition
C. overlap in resource utilization
D. Both A and B
E. All of the above

Question 15

Competition

Answer 15

interaction between populations in which growth rates decrease for both

Question 16

What is an example of an indirect exploitation?

Answer 16

Resource availability for Carbon

Question 17

What is an example of interference?

Answer 17

direct physical exclusion for space

Question 18

Competitive Exclusion

Answer 18

if there is significant niche overlap and limited resources, one population will drive the other to extinction

Question 19

When does coexistance of two species occur?

Answer 19

Interspecific competition is weaker than intraspecific competition

Question 20

In what ways does niche partitioning decrease competition?

Answer 20

1. Microenvironments
2. Variability
   
   • spatial heterogeneity
   • diurnal
   • seasonality
3. Multiplicity of resources
4. Other biological interactions