Exam 4

Question 1

Disturbance

Answer 1

Any chance event that changes the amount of biomass in a community (productivity)
ex. fire, hurricane, flood, pH changes, heat wave, volcano, etc.

Question 2

Succession

Answer 2

How an environment rebounds after a disturbance (usually multiple stages that value different things)

Question 3

Early succession characteristics

Answer 3

-lots of sunlight (lets many plants grow)
-harsh abiotic conditions (no trees or plants holding in water or controlling temp yet)
-small seed size (quick dispersal and they get to produce many at once - there’s a greater likelihood of a plant surviving when there’s a bajillion of them)
-fast growth rate (won’t live long so need to pass genes on as soon as possible)
-quick lifespan (gets through many generations)
*many fitness tradeoffs

Question 4

Late successional characteristics

Answer 4

-not much sunlight (shaded by trees)
-benign abiotic conditions (shade from trees controls temp, plant roots hold in water)
-big seed size (concentrates on growing a healthy offspring that will grow old and big)
-slow growth rate (focuses on growing a big and healthy individual)
-long lifespan (will generate more offspring that will also live long)

Question 5

Sexual selection

Answer 5

Very variable
Basically: alleles lead to increased fitness (success in mating) increase in frequency

Question 6

Haber-Bosch

Answer 6

Fixing nitrogen method that helps make 50% of all world’s food (but also used as a biological weapon)

Question 7

Dead zones

Answer 7

Too many nutrients fueling the plant life in an area so animal life suffers (no oxygen left)

Question 8

NPP

Answer 8

Sunlight energy actually used for growth (turned into biomass instead of just maintenance)
-much NPP is unavailable for consumption so only about 10% goes up trophic levels (ie wood); efficiency also goes down as higher predators have to expend more energy to catch prey

Question 9

Ectotherms are more efficient consumers because…

Answer 9

they don’t need to use as much energy for temperature regulation

Question 10

Reationships

Answer 10

Commensalism + -
Mutualism + +
Competition - -
Parasitism + -
Consumption + -

Question 11

Induced defenses

Answer 11

Prey get them in response to predator presence (shell thickness in mussels, bee stinger)

Question 12

Standing defenses

Answer 12

Prey always have them (spines on hedgehogs)

Question 13

Parasitism and Virulence

Answer 13

Parasites evolve to be virulent when transmission is high (ebola is very virulent as the parasite can invade many new prey by coming out of the host) and not virulent when transmission is low (choose to incubate in host)

Parasites can also manipulate hosts by changing their brain chemistry (mice are drawn to cats when infected with a parasite that reproduces in cats)

Question 14

Threats to Biodiversity

Answer 14

Climate change (changing habitats and ranges)
Invasive species (small realized niche)
Habitat fragmentation (gene flow, increased effect of genetic drift, in breeding depression)

Question 15

Conservation

Answer 15

Wildlife corridors
Reduced population growth
Biodiversity increase (conservation of endangered species with small geographic ranges (biodiversity hotspots), population recovery)
Community science (have everyday people do some research and data collection for research studies)
Make informed decisions with the consequences they’ll have on the entrainment in mind)

Question 16

P value wording

Answer 16

”% chance of finding this data set if the null hypothesis is true”

Question 17

P value for T test

Answer 17

”% chance of finding a difference between means if the null is true (no difference in populations)”

Question 18

P Value for Linear Regression

Answer 18

”% chance of finding this great of a slope if the null is true”

Question 19

R-squared for Linear Regression

Answer 19

”% of variation in y is explainable by variation in x”

Question 20

Chi-Squared

Answer 20

“finding a relationship vs not finding a relationship between variables”