Mid-year Review

Ecology​

​Scientific Method ( steps)

1. Make observations ( formulate a question)

2. Form a hypothesis ( testable explanation)

3. Experiment

4. analyze data

5. Refine hypothesis or redefine if necessary and retest.

   Key to all experiments: must have large sample size, at least 3 experiment trials.

   Variables:

   1. independent variable ( only 1 tested a time) :is the factor the investigator changes.

   1. Dependent variable: factor affected by independent variable ( what is measured, observed or recorded)

   2. Controlled variables: Factors that are kept constant

   3. Control group: group not being tested on, used as a comparison.

   4. experimental group: group that IS being tested, included the Independent variable.

Independent variable: the factor being manipulated (what am I changing)

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Dependent variable: the factor being measured ​

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Ch. 1 - Scientific Method, What is Biology, Origin of Life

Experiment Variables

The bottom of a food web, or ecological pyramid will always have 100% energy available and it will pass approx. 10% of energy to the next level. Most energy lost as HEAT

This is known as 10%rule

​Ch. 3-7 - Ecology

Energy in an Ecosystem

• Autotrophs = organisms that are able to automatically make their own food (energy), also known as producers, they perform photosynthesis or chemosynthesis (ex: plants,

  bacteria)

• Heterotrophs = organisms that must consume other organisms to gain energy, also known as consumers (ex: animals)

​Ch. 3-7 - Ecology

Autotroph vs. Heterotroph

​Ch. 3-7 - Ecology

Food Chains

​Remember that the arrows point to where the energy is going NOT who is eating who.

Carrying capacity - The maximum amount of organisms that can an ecosystem can hold given the resources it has​

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Limiting factors - decrease carrying capacity ​

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​Ch. 3-7 - Ecology

Carrying Capacity & Limiting Factors

• Limiting factor any factor that will limit the size of a population.​

• Density -dependent limiting factors: Number of organisms in the environment influences the population size.

  • Examples: Competition, Disease, Water/food resources

• Density Independent limiting factors: Number of organisms in the environment DO NOT influence the population size.

  • Examples: Natural disasters ( forest fires, floods, etc.

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​Ch. 3-7 - Ecology

Limiting Factors

​Growth Curves

​Symbiotic Relationships

​Ch. 3-7 - Ecology

Ecological Succession

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• Succession is a series of progressive changes in the composition of an ecological community over time.

• In primary succession, newly exposed or newly formed rock is colonized by living things for the first time.​

• In secondary succession, an area previously occupied by living things is disturbed—disrupted—then recolonized following the disturbance.

​Ch. 3-7 - Ecology

Ecological Succession

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• Succession is a series of progressive changes in the composition of an ecological community over time.

• In primary succession, newly exposed or newly formed rock is colonized by living things for the first time.​

• In secondary succession, an area previously occupied by living things is disturbed—disrupted—then recolonized following the disturbance.

​Ch. 3-7 - Ecology

Human Impact

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• ​Main cause of global warming = increased green house gasses

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• Main cause of flooding in south FL = sea level rising due to climate change ​

​Green house Effect

Properties of Water

​Target: I can discuss the properties of water, including cohesion, adhesion, ability to moderate temperature, freezing and boiling points, and solvent, and can identify how each contributes to Earth’s suitability as an environment for life.

Water is a polar molecule.

Polarity = a molecule with a slightly negative charge and slightly positive charge.

Water molecules bond with other water molecules through hydrogen bonding

​Polarity

​Cohesion is the attraction of like molecules - water molecule to water molecule

Cohesion of water molecules happens because of hydrogen bonding (polarity)

​​Cohesion

​Adhesion is the attraction of water molecules to different substances - water molecule to another molecule

Adhesion of water molecules happens because of hydrogen bonding (polarity)

Adhesion

Cohesion in the environment

●Cohesion allows for water to
move upward against gravity
in huge plants like the giant
Sequoia Trees.

●Without cohesion, water
would not reach the upper
branches and leaves of trees.

This Photo by Unknown Author is licensed under CC BY

​Water has a high heat capacity = water resists change in temperature

Moderate Temperature/High Heat Capacity