AP Bio - Populations test

Definitions

1. Population – A group of individuals of the same species living in a specific area at the same time.

2. Population Density – The number of individuals per unit area or volume.

3. Immigration – The movement of individuals into a population from another location.

4. Emigration – The movement of individuals out of a population to another location.

5. Exponential Growth – A rapid increase in population size when resources are unlimited, shown as a J-shaped curve on a graph.

6. Carrying Capacity – The maximum number of individuals in a population that an environment can support over time.

7. Limiting Factors – Environmental conditions that restrict population growth, such as food, space, or predation.

Questions

1. Competition among species – Occurs when different species compete for the same limited resources (e.g., food, space, light).

2. Example of a parasite – A tick on a dog.
   Definition – An organism that lives on or in a host, harming it while benefiting itself.

3. Taxis vs. Kinesis:

   • Taxis: Directed movement toward or away from a stimulus (e.g., moth flying toward light).

   • Kinesis: Random movement in response to stimulus intensity (e.g., pill bugs moving more in dry areas).

4. Innate vs. Learned behaviors:

   • Innate: Inborn and automatic (e.g., spider spinning a web).

   • Learned: Acquired through experience (e.g., dog learning to sit on command).

5. Two types of limiting factors:

   • Density-dependent: Affected by population size (e.g., disease, competition).

   • Density-independent: Affects all populations regardless of size (e.g., natural disasters).

6. Logistic vs. Exponential growth:

   • Exponential: Rapid, unrestricted growth (J-curve).

   • Logistic: Growth slows as population reaches carrying capacity (S-curve).

   • Examples:

     • Exponential: Bacteria in ideal conditions.

     • Logistic: Deer population in a forest over time.

7. Carrying Capacity Definition: The largest population size an environment can sustain long-term.
   If exceeded: Resources become limited, leading to die-offs or population decline.

8. Environmental factors influencing carrying capacity:

   • Availability of food, water, shelter, space, and presence of predators or diseases.

9. Is surpassing carrying capacity negative?
   Yes, it can lead to overuse of resources, starvation, and population crashes, impacting the ecosystem.

10. Keystone Species: A species with a major impact on its ecosystem’s structure.
    Example: Sea otters control sea urchin populations and protect kelp forests.

11. Animal Groupings Pros and Cons:

• Advantages: Protection from predators, cooperative hunting, warmth.

• Disadvantages: Disease spread, increased competition for resources.

12. Intraspecific vs. Interspecific competition:

• Intraspecific: Within the same species.

• Interspecific: Between different species.

13. Population Sampling Methods:

• Random: Unbiased but may miss patterns.

• Plot (quadrant): Good for stationary organisms, limited to small areas.

• Catch-and-release (mark-recapture): Works for mobile animals, can be inaccurate if animals avoid recapture.

14. Invasive Species vs. GMOs:

• Invasive Species: Non-native, outcompetes natives (e.g., zebra mussels).

• GMO: Genetically modified for specific traits; may disrupt ecosystems (e.g., GMO salmon).

15. Real-world Symbiosis Examples:

• Mutualism: Bees and flowers – both benefit.

• Commensalism: Barnacles on whales – barnacles benefit, whales unaffected.

• Parasitism: Tapeworm in humans – tapeworm benefits, human harmed.

16. Predator/Prey Dynamics:
    As prey increases, predators increase. As predators overhunt, prey decline, followed by predator decline. (e.g., wolves and deer.)

17. Biomass in Ecosystems:
    The total mass of living organisms in a given area; indicates available energy at each trophic level.

18. Human Population Growth:
    Exponential, due to advanced medicine, agriculture, and technology allowing higher survival and reproduction rates.