chapter 20 Flashcards
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Describe the difference between primary and secondary succession. Include an example of when each may happen, as well as what types of organisms you would expect to populate the area first.
Primary succession - First organisms to settle in a new area with no soil. Usually lichen, bacteria and/or mosses.
AND
Secondary succession - Organisms resettling an area after a major disturbance (fire, flood, etc.). Soil is still intact, so plants can be the first organisms there.
What is a pioneer species? What type of succession would we find them in?
The first species in a new area. We find them in primary succession, as they are able to turn the rock/uninhabitable soil into fertile soil for growth.
What is the Level of Organization in order. Smallest to biggest
- Cell
- Tissue
- Organ
- Organ System
5.Organism
6.Population
7.Community
8.Ecosystem
9.Biome
10.Biosphere
How is it possible that prey might actually need predators in an ecosystem? Describe an example of this being the case.
The predator-prey cycle is important to prey because without the predators, it becomes possible for the prey to overgraze. This would eliminate the prey’s food source and cause them to die out. The predators eat the prey and keep them from overgrazing.
Type of symbiotic relationship
- Mutualism
2.Commensalism - Parasitism
What is the competitive exclusion principle? Give an example using two plants in the same community.
Two organisms with the same niche will have competition for resources in a shared ecosystem, and usually one will win out over the other. If there was one plant that was taller than the other, it would have an advantage in gaining access to sunlight compared to the other plant. Over time, this plant could be expected to exclude the other plant from this resource, causing it to die out.
Why is biodiversity important to an ecosystem? What could happen when we lose biodiversity?
Biodiversity is the safety net that keeps an ecosystem from falling apart during disturbances. Without biodiversity, a disturbance that affects one population is much more likely to have significant effects on the other populations in that community. Biodiversity increases the ecosystem’s resistance AND resilience to disturbances.
Defense mechanisms and give an example of each:
- Physical
The physical appearances that something may have to stay alive
EX. Camouflage, mimicry - Mechanical
The weapons or defenses that an organism may have on its body
Stingers, thorns, shells, fists - Chemical
The chemical substances that an organism may use to defend itself
Toxins, poisons, foul smells
4.Behavioral
The actions that an organism takes to keep itself alive
Playing dead, hiding, running away
The pesticide Round-Up is commonly used in gardens across the United States to kill weeds. However, some chemicals in Round-Up do not naturally dissipate over time, and stay within any living organisms that ingest it. These chemicals can cause birth defects and mutations that can decrease the likelihood for survival. Describe how this may affect the food web of a local ecosystem. Include which organisms would be most affected, and explain why.
Primary consumers that eat the plants affected by Round-Up will gain a small amount of these toxins. Secondary consumers will then get more, and tertiary consumers will get more than that. The animals in the highest levels of the food web will be the most impacted, and will have the greatest frequency of negative effects, since the toxin biomagnifies as it moves through each trophic level.
What is eutrophication? Describe how the process happens, including why it is such a problem in modern agriculture.
Nitrogen and phosphorus are artificially sprayed onto crops. These chemicals are then washed off by precipitation, and are carried into local waterways. Once in a body of water, they will cause the algae there to grow rapidly. Once the algae die, they are broken down by bacteria, which use oxygen to break them down. The high amount of death means a high amount of oxygen is used, creating a hypoxic environment that kills all of the life in that area. This is a major problem in modern agriculture, as artificial fertilizers are extremely common and are sprayed heavily in many areas.
What are the six most common elements found in living things? What two do we usually find together? What is the acronym we used to remember them all?
CHNOPS - Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur
We usually find hydrogen and oxygen together as H2O, or water
Describe how the water cycle is important to other biogeochemical cycles.
Water carries many of the other elements to different areas. It can erode rocks and carry their carbon, and can pull nitrogen and phosphorus from fertilizers into local waterways.
A producer has a total net primary production of 1000 kilojoules (kJ) of energy. It is then eaten by a primary consumer, which is eaten by a secondary consumer. How much energy would a tertiary consumer gain from eating that secondary consumer, assuming no other food was consumed?
1 kJ of energy. 1000->100->10->1
Give two examples of abiotic factors that affect biotic factors in an ecosystem and explain how.
Sunlight impacts how many plants are able to survive in an area. Soil depth would affect how large of plants are able to grow in an area, with things like large trees not being able to survive in areas with shallow soil.
Explain the difference between a food chain and a food web. Why is one better than the other?
Food chains only show one line of things eating other things in that ecosystem. A food web shows the entire picture of every feeding relationship within that ecosystem. A food web is better because it gives us a full visualization of the ecosystem’s trophic levels.
