Ecology Lab Exam

Ecology

The study of how organisms interact with, and are affected by their environment.

Abiotic Factors

Non-living elements of an environment, such as temperature, salinity, pH, nutrients

Biotic Factors

Living elements of an environment, such as animals, trees, bugs, bacteria, etc.

Abiotic affecting biotic

Temperature affects different animals behaviors

Purpose of lab 1 in ecology section

To understand how abiotic and biotic variables affect a community’s structure and distribution

Biotic to biotic

Seal mating leads to an increase in competition for space

Abiotic to abiotic

High sun exposure leads to less soil moisture,

Biotic to abiotic

Animals peeing in a lake leads to more nitrogen in that lake

Abundance

The number of organisms

Diversity

The number of different species

How does sunlight intensity differ between each side of the mountain slope in the northern hemisphere? How can this affect abundance and diversity of organism between each side of the slope?

The south facing slope would get harsh direct sunlight for all of the day. More diversity on the north facing slope, possibly higher abundance of a single organism that is adapted well to high sunlight

Scientific process

observe, question, hypothesis, test, analyze data

What did we measure in this lab

Soil temp, Air temp, Soil pH, Soil moisture, light intensity

Mean

The averageD

standard deviation

dispersion of data points around the mean

Standard error of mean

How far sample mean differs from the actual population mean

What tools did we use

thermometer, soil moisture probe

What were your hypothesis for each abiotic factos

Why is it important to run statistical analysis on data

To see if the data is actually significant or not, prevents from human judgement error.

Discrete data

A count (chi square test)

Continuous data

Measured (T-test, one-way ANOVA, Correlation, regression)

Null hypothesis

is always assumed to be true, assumes there is no change. Accepted when the data is not significant

Alternative hypothesis

The factor that is being tested for, accepted when data is proved to be significant

one-tailed experiment

Directional experiment, in the hypothesis it states which direction is thought to be different

two-tailed experiemtn

non-directional experiment, the hypothesis simply states there will be a difference but there is no guess on which way

T-test

used when there is 2 groups of independent samples of continuous data

Chi square test

used when the data is discrete

one-way ANOVA

More then 2 groups of independent samples of continuous data

Correlation

To understand if two quantitative variables are negatively, positively, or not correlated

Regression

1 independent variable and 1 dependent variable see if they are related

R-square value

tells you how close the data is to the trendline, the closer the number is to 1, the closer your data points are. the number is in-between 0 and 1

p-value

p>0.05 then the data is not significant, and the null is failed to be rejected

Metabolism

The chemical processes that occuring in a living organism and are essential for the regulation of life.

Aerobic Respiration

Uses oxygen to break down glucose to create atp and co2

Anaerobic respiration

Breaks down glucose into ATP without oxygen. Produces lots of end products. Less effective than aerobic.

Catabolism

The process of breaking down large organic molecules for energy (releases energy)

Anabolism

Using smaller things to make larger organic molecules (requires energy)

Nucleic Acid

Macromolecule formed from nucleotides

Carbohydrates

Macromolecule formed from monosaccharide

Lipid

Macromolecule, formed from glycerol and fatty acids

Protein

Macromolecule, formed from amino acids

Photosynthesis

6CO2 + 12H2O → C6H12O6 + 6O2 + 6 H2O (must be in the presence of chlorophyll and light)

Light dependent reaction

Energy from light splits water and produces oxygen

Light independent reaction

Energy from first reaction is used to reduce co2 into glucose R

Redox

Allows for carbon fixation, turning inorganic carbon into organic carbon

Cellular respiration

C6H12O6 + 6O2 → 6 CO2 + 6H2O + ATP

Oxidation reaction

conversion of organic molecule into an inorganic molecule. Glucose → Carbon dioxide

RQ quotient

The ratio in which co2 expires vs the amount of O2 consumed. Between 0.7-1 depending on the macromolecule being consumed

Methods and results of the metabolism experiment

More photosynthesis happens in the presence of light, and more cellular respiration happens in dark.

transpiration

The process of water absorbed from the roots, and traveling through the stem, and then evaporates off the leaves, through the stomata.

turgor pressure

The pressure on plant cells due to osmotic pressure. Allows the plant to stand upright

How does water enter and exit the plant?

Evaporates off the leaves, through the stomata

photometer

measures the rate at which a plant draws up water. (can be used to estimate transpiration, since when transpiration occurs the plant will draw up water)

Explain the photometer set up and procedures for measuring each abiotic factor

A tube with water placed in a u-shape. With graduations on one side, and a plant stem firmly placed in the other side.

How is transpiration affected by each abiotic factor tested?

Humidity = - transpiration, Heat = + transpiration, Closed Stomata = - transpiration

How is transpiration affected by surface area?

the greater the surface area, the greater the transpiration

N prey

Density of prey (# of prey encountered per unit of time )

E prey

Caloric value of each prey item

C searching

Cost of searching for each prey item

H

Handling time (wrangling, killing prey)

Population

individuals of the same species that live together and interact with eachother

population growth

birth and immigration

Density independent

Abiotic factors such as natural disasters

Density dependent

biotic factors such as disease outbreak, competition for food space and mate, carrying capacity

Population A: discrete population with overlapping generations

^N/^T= lamda N0 (but everyone lives and noone dies, the growth is exponential)

population B: Discrete population with non-overlapping generations

^N/^T= lamda N0 (the adults that reproduced in that cycle die off)

basic rules of sustainable fishing

Fishing a little bit of everything so the population relations stay relatively the same

population decline

deaths and emigration

discrete reproduction

Animals that reproduce only at a certain time during a year, examples bears, seals, dear

Continuous reproduction

The season has no affect on population growth and the animals can give birth whenever. Rats

Non-overlapping generations

The parents are not around when offspring reaches sexual maturity O

Overlapping generation

The parents are around when offspring reaches sexual maturity and can sometimes reproduce along with them.

generation time

the time of birth, till when the individual reaches sexual maturity

Age class structure

Relative proportions of pre and post reproductive individuals and reproducing individuals.