#AP Environmental Science: Reproductive Strategies - The Night Before

Hey there, future AP Environmental Science superstar! Let's get you prepped and confident for tomorrow. We're diving into reproductive strategies, a key area that pops up everywhere on the exam. Think of this as your ultimate cheat sheet – concise, clear, and designed to make those connections click. Let's do this!

#Reproductive Strategies: r-selected vs. K-selected

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Species adopt different reproductive strategies based on their environment. It's all about maximizing survival and passing on genes. We'll be looking at two ends of a spectrum: r-selected and K-selected species. Think of it like a sliding scale, not a strict either/or. 💡

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• r-selected: High rate of reproduction. Think 'rabbits' - lots of babies, not much parental care. They are the 'quantity over quality' species.
• K-selected: Live near the Karrying capacity of their environment. Think 'koalas' - few babies, lots of care. They are the 'quality over quantity' species.

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When analyzing a species, ask these questions:

• What's their average size?
• How much parental care do they invest?
• How many offspring do they produce?
• How competitive is their environment?
• What role do they play in ecological succession?
• Are they invasive or affected by invasive species?

#R-Selected Species: Live Fast, Die Young

#Characteristics

• Size: Generally small. 🐁
• Parental Care: Little to none. 💔
• Offspring: Many! They have a high biotic potential. 📈
• Lifespan: Short. ⏳
• Reproduction: Often reproduce only once in their lifetime. 🔄
• Competition: Low competition for resources. 💪
• Survivorship Curve: Type III (most die young). 📉
• Ecological Role: Pioneer species (first to colonize).
• Invasive Species: Often are the invasive species. 🌍

#Image Courtesy of Pixabay

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#K-Selected Species: Quality over Quantity

#Characteristics

• Size: Generally larger. 🐘
• Parental Care: Lots of care! ❤️
• Offspring: Few. 👶
• Lifespan: Longer. ⌛
• Reproduction: Reproduce multiple times in their lifetime. 🔁
• Competition: High competition for resources. ⚔️
• Survivorship Curve: Type I or II (most survive to adulthood). 📊
• Ecological Role: Late-stage successors.
• Invasive Species: Often affected by invasive species. 😥

#Image Courtesy of Pixabay

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#Comparing R and K Selected Species

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• Population Growth: r-selected species often show exponential growth, while K-selected species tend to stabilize near the carrying capacity.
• Survivorship Curves: Directly linked to r/K strategies. Type III for r-selected, Type I/II for K-selected.
• Ecological Succession: r-selected species are pioneers, K-selected species are late-successional.
• Invasive Species: Understanding r/K helps predict which species are likely to become invasive.

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• Thinking it's black and white: Remember, it's a spectrum. Some species fall in the middle.
• Forgetting the 'why': Don't just memorize the traits. Understand why each strategy evolved.
• Mixing up survivorship curves: Type III is for r-selected, Type I/II for K-selected.

#Final Exam Focus

#Top Priority Topics

• Distinguish between r and K selected species: Know their characteristics and how they relate to environmental conditions.
• Survivorship curves: Be able to identify and interpret them in the context of r/K selection.
• Ecological Succession: Understand the role of r and K species in different stages of succession.
• Invasive Species: Recognize how reproductive strategies contribute to invasiveness.

#Common Question Types

• Multiple Choice: Expect questions that ask you to classify species as r or K-selected, interpret survivorship curves, or predict the impact of environmental changes.
• Free Response: FRQs often ask you to analyze a scenario involving population growth, competition, and/or invasive species, requiring you to apply your understanding of r/K strategies.

#Last-Minute Tips

• Time Management: Don't spend too long on any single question. If you're stuck, move on and come back later.
• Read Carefully: Pay close attention to the wording of each question. AP exams are tricky!
• Stay Calm: You've got this! Take deep breaths and trust your preparation.

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Practice Question

Practice Questions

#Multiple Choice Questions

1. Which of the following is a characteristic of a K-selected species? (A) Short lifespan (B) High reproductive rate (C) Extensive parental care (D) Early sexual maturity

2. A species that exhibits a Type III survivorship curve is most likely: (A) A large mammal with a long lifespan (B) An insect with a high reproductive rate (C) A bird with moderate parental care (D) A plant with slow growth and late maturity

3. Which of the following is NOT a typical trait of r-selected species? (A) Small body size (B) High biotic potential (C) Long lifespan (D) Low parental investment

#Free Response Question

A remote island ecosystem is home to a population of native birds that are K-selected. A new species of fast-reproducing rodents (r-selected) is accidentally introduced to the island.

(a) Describe THREE characteristics of the native birds that classify them as K-selected species. (3 points) (b) Explain TWO reasons why the introduced rodent species is likely to become invasive. (2 points) (c) Predict ONE possible long-term effect of the rodent invasion on the native bird population. (1 point) (d) Suggest ONE management strategy that could be used to control the rodent population and explain why it would be effective. (2 points)

#FRQ Scoring Breakdown

(a) Describe THREE characteristics of the native birds that classify them as K-selected species. (3 points) * One point for each of the following (max 3): * Large body size * Long lifespan * Low reproductive rate * Extensive parental care * Late sexual maturity

(b) Explain TWO reasons why the introduced rodent species is likely to become invasive. (2 points) * One point for each of the following (max 2): * High reproductive rate (or many offspring) * Short generation time * Ability to adapt to new environments * Lack of natural predators in the new environment

(c) Predict ONE possible long-term effect of the rodent invasion on the native bird population. (1 point) * One point for any of the following: * Decline in bird population due to competition for resources * Decline in bird population due to predation * Extinction of bird population

(d) Suggest ONE management strategy that could be used to control the rodent population and explain why it would be effective. (2 points) * One point for a valid management strategy and one point for the explanation (max 2): * Strategy: Introducing a natural predator of the rodents. * Explanation: Predators can help control the rodent population through predation. * Strategy: Using traps or poison. * Explanation: Traps or poison can directly reduce the rodent population. * Strategy: Introducing a disease that targets the rodents. * Explanation: Diseases can spread and reduce the rodent population.

Alright, you've got this! Go ace that exam!