lab quiz 1 Flashcards
phytophages
leaf eating insects
frugivores
fruit eating insects
Monarch butterfly
feeds on milkweed. Produces milky sap which acts as skin irritant. Monarch butterflies consume this plant and then are poisonous to birds that eat them
Simple random sampling
pooling all groups together and choosing number… for leaf experiment could have ended up with 15 leaves from tolmie and 5 leaves from uvic
Stratified random sampling
dividing into groups first… then randomly selecting from those groups
3 ecological issues concerning the effects of herbivory
1) Herbivores at controlled levels vs outbreak levels
2) effects of herbivores on primary productivity
3) what factors control herbivores? ex. plant chemistry, food quality, defense chemicals etc.
pseudoreplication
- treating samples that are not independent as independent samples… decreases validity
- measuring leaves on trees, want to have an estimate population at each position… 2 leaves from the same trees and averaging isn’t good
What does the confidence interval mean if it does not include 0
means there is a difference
What does it mean if the p-value is less than the alpha value
-there is evidence to reject Ho and lend support for Ha
what does an alpha value of 0.05 mean
means that the p-value would have a 5% chance of error
Pros of stratified random sampling?
-controls for other variables
Cons of stratified random sampling
- when researchers can’t classify every member of a population into a subgroup
- overlapping: when subjects fall into multiple subgroups
Pros simple random samling
-easy and accurate
cons simple random samplihgn
- pools all the numbers… samples that are way out of the normal range will deviate the results a lot…
- doesn’t control for variables so much
what are gary oaks named after?
Nicholas Gary
Where trees are Gary oaks found around
1) arbutus
2) Douglas Fir