Biology and Ecology: Key Concepts in Scientific Methods, Biogeography, and Ecosystem Dynamics

Which of the following is best to answer what, where, who and when questions?

Observations

Which of the following is a synthesis of the best available to science to create predictive models?

Theory

This is when you manipulate or change an independent variable in an experiment

Treatment

Scientists test a hypothesis by

comparing the results of the treatment to the control

If a scientist wanted to determine the effect of Phosphate nutrients on the biodiversity of algae-eating insect larvae in a stream, then what could she use as the dependent-variable?

the species richness of insects

*Anna's Hummingbird are often seen flying up and down in high loops above the sage scrub at BFS. State a hypothesis that explains the function of this behavior. Explain how you can do an experiment to test your hypothesis? What would be the control and treatment? What data would you record?

Hypothesis: If Anna's hummingbirds are flying in loops, then it is for protection because the hummingbirds feel threatened by a predator.

My control would be to study their habits without interfering at all. My treatment would be to make a predator, and study the birds habits/how often they loop.

What is the main difference in the chemical composition of the Earth's crust compared to the whole planet?

Less iron in crust

What is the most important force that causes the movement of crustal plates?

convection of the mantle

What do the red arrows on this map inditcate?

direction of plate movement at boundaries

Which type of rock forms when a prior kind of rock melts and then cools?

Metamorphic

Which of the following is NOT an important factor in soil formation?

Presence of groundwater

Which of the following is NOT an important function of soil in ecosystems?

salinification of salts

The organic part of soil (humus) does all of the following except:

makes soil vulnerable to drought, and disease

All of the following are potentially renewable resources except:

crude oil

The primary cause of land degradation worldwide is:

erosion from croplands

*Explain how crop rotation, no till, and cover crops work to improve soil

Crop rotation: balances the soil, increases nutrients

Cover crops: protects farm land from weeds, reduces soil erosion, returns nutrients to soil

No till: reduces soil erosion

Where does most of the energy go in ecosystems?

heat and waste

What process causes the regeneration of nutrients?

biogeochemical cycles

Which of the following can be a density-dependent factor that affects population size?

food shortages

According to the logistic growth equation

population growth is zero when N equals K

What would you predict when resources are limited, and two species have the same realized niche?

competitive exclusion

*Explain the N-cycle. What keeps it in balance? What environmental problem is caused if human create an imbalance in the cycle?

• The nitrogen cycle is fundamental for human and animal life. We absorb the nutrient from nitrogen in a variety of ways (one example is food), then it can exit our bodies and the cycle restarts.

• It stays in balanced by bacteria which are keystone species that fix N and complete the cycle

• It becomes unbalanced when people use, for example, excess fertilizer.

• When the N cycle is imbalanced by N pollution it causes eutrophication

Which types of islands tend to have the highest rates of endemism

Microcontinents

Most Biodiversity Hot Spots occur:

in tropical forests and dry shrublands

The concept that all species are related to each other in varying degrees comes from the theory of:

modification from common descent

Which of the following is an example of natural selection?

Birds with longer tails reproduce more

What is the best explanation of why certain biomes exist only at certain latitudes with a specific range of normal temperatures and precipitation?

Law of tolerance of the dominant giant species

*Explain how plate tectonics and evolution produce biogeographic regions and endemic species. Why are the fauna & flora of the southern continents so different from northern continents

*Pangaea split north and south creating different evolutionary trajectories

At the start of the earths creation, all of the continents were together and through plates tectonics shifting the continents drifted further and further away. The continents each had different temperatures, terrain, etc. which made some species have to adapt for survival. Some species thrived in one environment and went extinct in another.

In a similar way to species, fauna and fora experienced something similar. The southern continents are a place perfect for some fauna and flora to thrive while for some it was not a good environment.

In addition, due to isolation from the other continents have a big impact on why the fauna and flora are so different across the varying continents.