Lab midterm biol 215

what are null and alternate hypothesis

null: no effect

alternate: effect

what are 3 types of data?

qualitative:

categorical

quantitative:

continuous

discrete

Define standard deviation and variance:

standard deviation: how much the points are spread out or vary from avegrage

variance: how much data point scatter around centre or mean

what is the T sample test:

how likely it is that the observed pattern is due to random chance

works with large samples

categorical qualitative independent variables with 2 possible values and a numerical dependent variable

to determine a statistically significant difference between the means of the groups

whats the p value? say everything about it

it shows th eprob. that our results are due to random chance

always a decimal ratio (0-1)

never 0 or 1

if p value < 0.05 its a significant result. less than 5% that the pattern we r observing is due to random chance. we will reject the null and accept the alternate

define these: Herbivory, herbivores, phytiphages, frugivores

herbivory: interaction where plant is consumed by some consumer organism

herbivores: primary consumers

phytophages: leaf eating insects, mainly specialists

frugivores: fruits

what r physiological feeding adaptations animals got and 2 examples:

to avoid dying because of herbivores they grew thorns

they r pysiological responses like chewing

monarch butterfly: they eat poisoneous milk to be poisonous to birds

how do we calculate the percentage of leaf removed by herbivory:

area removed by herbivory / total area of leaf x 100%

what is stratified random sample:

its a probabiliy sampling method, divides population into smaller groups according to a shared characteristic and then randomly choose a participant

higher preision, lower error, more complex than simple random smapling

hwy is the mean value useful (2)

1. best representation of population as a whole

2. mean can be used for comparing populations or samples

define natural selection

variation of survival and reproduction that is associated ito a particular trait

whats the formula for shell aperture index?

Ia = [pi (L+(W/4)) to the 2]/H

deinfe a bar graph, histogram and interval plot:

bar graph: size-frequency distribution, symmetrical graph bar is in the middle

histogram: how often different values occur in data set

interval plot: complete chart

define CI, CI 95%, Standard error bars, interval bars:

CI: range of plausible values for the true population average

CI 95%: 95 percent confident that true population falls inside this range

Standard error bars: bars that show precision of sample mean, how uch avg. would change i you did the expeiment again

Interval bars: actual I shaped lines drawn in graphs, can be of 95 CI, SEM or St.dev

accuracy and precision?

accuracy: how close u r to the right answer

precision: how close ur measurements r to each other

• this one has CL

  • large, not precise

  • small, more precise

if interval overlap, they are _____________

if interval dont overlap, __________

overlap: not signifcant

not overlap: significant

define these:

life history trait: A life history trait is a structural, behavioral, or physiological feature of an organism that directly affects its survival, development, and reproduction. These traits shape the organism's life cycle strategy and determine how it allocates limited energy.

abundance: The total number of individuals of a specific species present within a defined study area.:

density: The number of individuals per unit area or volume (e.g., 50 spiders per square meter).

quadrat and transect: stimating population size using tools like quadrats or transects to count individuals in small, defined areas and then extrapolating that data across the larger region.

for lab 3, what was the research qustion, hypothesis, null and alternate hypothesis:

from lab 3, whats Rsquare?

from lab 3: according to the research paper 1, what were they tlaking about?

speies foraging higher in the vegetation: had winged prey. Species at lower vegetation had jumping, larger prey.

web radius, spider size and web height explained the variation the most.

Spider webs were located by having sampling areas with walking transects.

When web with a spider was found, the vegetation height and height of web hub were measured

quantitative sampling with quadrats: pros is that it gives adequate estimates of spider densities, cons is that it underestimates abundances of orthopterans.

from lab 3, acording to research paper 2:

resource availability is the most important factor influencing spider evolution because when food is scarce, the metaboli rate of spiders can withstand longer period of time without food.

When spide denstities increase, spiders eat more to build up more fat

constraints imposed of orb web architecture: 1) constraints by egineering specifications for tensile structure. 2) by macromolecular structure of silk proteins. 3) aerial nets restrict environments

four characteristic that limit site availability to spiders that spin aerial nets: size, changes, diversification of web characteristics and reproductive mode in aracnoid spiders.

2 attributes that r the most important physiological factors infkuencing aracnoid evolution: ability of spiders to withstand food deprivation and to respond rapidly when food is availablke

what r line and point transects:

talk more about transects

used for recording observations along a predefined route

can be used for exmaining species-habitat relationships

line: recording data occurs continually.

point: recording data at regular intervals along the route

talk about quadrats:

used to know the types of plants and animals in a habitat, how many there r, so we collect samples of a represnetative population

samples r taken using a standard sampling unit

quadrats r the small replicated areas where we count, most used size is 1m square

to sample our population of interest we must decide on: 1) number of qudrats to sample 2) what size quadrat to use 3) placement of the quadrats

whats the advantages and disadvantages of increasing the quadrat number?

whats the advantage and disadvantage of increaaisng the quedrat size?

Increasing the number of quadrats (sample size) in an ecology study significantly improves the accuracy of your data, but it requires a much larger investment of time and effort.

Increasing the size of each quadrat alters how effectively you sample an ecosystem. While larger quadrats are essential for capturing larger or sparse organisms, they drastically increase sampling time and make counting individual organisms much harder

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