Essential Idea:  The continued survival of living organisms including humans depends on sustainable communities.

• Outline answer to each objective statement for topic 4.1 (coming soon)
• Quizlet study set for this topic

At SHS, Topic 4.1 is taught in the following class unit(s):​​​​

• Concepts of Biology (unit 1)
• Speciation (unit 21)
• Communities and Ecosystems (unit 24)
• Energy Flow through Ecosystem (unit 25)
• Nutrient Cycles (unit 26)

Statements & Objectives:

4.1.U1  Species are groups of organisms that can potentially interbreed to produce fertile offspring.​

• Describe limitations of the biological species concept.
• Define species according to the biological species concept.

4.1.U2  Members of a species may be reproductively isolated in separate populations.

• Define population.
• Outline how reproductive isolation can lead to speciation.

4.1.U3  Species have either an autotrophic or heterotrophic method of nutrition (a few species have both methods).

• Define autotroph and heterotroph.

4.1.U4  Consumers are heterotrophs that feed on living organisms by ingestion.

• Describe the feeding behaviors of consumers.
• List three example consumer organisms.​

4.1.U5  Detrivores are heterotrophs that obtain organic nutrients from detritus by internal digestion.

• Describe the feeding behaviors of detritivores.
• List two example detritivore organisms.

4.1.U6  Saprotrophs are heterotrophs that obtain organic nutrients from dead organisms by external digestion.​

• Describe the feeding behaviors of saprotrophs.
• List two example saprotroph organisms.

4.1.U7  A community is formed by populations of different species living together and interacting with each other.​

• Define species, population and community.
• Give an example of a community of organisms.

4.1.U8  A community forms an ecosystem by its interactions with the abiotic environment.

• Define abiotic and ecosystem.

4.1.U9  Autotrophs obtain inorganic nutrients from the abiotic environment.

• Define nutrient.
• List the common nutrients needed by organisms.
• Outline how nutrients enter living systems.

4.1.U10  The supply of inorganic nutrients is maintained by nutrient recycling.

• State that chemical elements can be recycled but energy can not.
• Outline the generalized flow of nutrients between the abiotic and biotic components of an ecosystem. ​

4.1.U11 Ecosystems have the potential to be sustainable over long periods of time.

• Define sustainability.​
• Give an example of an unsustainable practice.
• Outline three requirements of a sustainable ecosystem.

4.1.S1  Classifying species as autotrophs, consumers, detrivores or saprotrophs from a knowledge of their mode of nutrition.

• Use a dichotomous key to identify the mode of nutrition of an organism.​

4.1.S2  Testing for association between two species using the chi-squared test with data obtained from quadrat sampling.​

• Outline why sampling must be random.
• Explain methods of random sampling, including the use of a quadrat.
• State the null and alternative hypothesis of the chi-square test of association.
• Use a contingency table to complete a chi-square test of association.

4.1.S3  Recognizing and interpreting statistical significance.

• Calculate a chi-square statistic based on observed and expected values.  
• State the null and alternative hypothesis of statistical tests.
• Determine if the null hypothesis is supported or rejected given a critical value and a calculated statistic.
• State the minimum acceptable significance level (p value) in published research.
• Explain the meaning of a “statistically significant” result, including the probability of chance having a role in the result.

4.1.S4  Setting up sealed mecocosms to try to establish sustainability. (Practical 5)

• Define mesocosm.
• List three example mesocosms.
• Outline requirements of setting up a mesocosm.

4.1.NOS  Looking for patterns, trends and discrepancies- plants and algae are mostly autotrophic but some are not.

• State the trend found in the nutritional patterns of plants and algae.
• Describe the discrepancy in the nutritional pattern of parasitic plants and algae.

In the News:

• The life that springs from dead leaves in streams (2020-08-06)
• Scientists put forward plan to create universal species list (2020-07-07)
• Unprecedented drought in an artificial ecosystem may reveal how rainforests will cope with climate change (2019-10-16)
• Early arrival of spring disrupts the mutualism between plants and pollinators (2019-07-12)
• Mixing it up in the web of life (2019-01-31)
• The Vanishing Night: Light Pollution Threatens Ecosystems (2018-10-01)
• The strange, messy history of self sustaining habitats (2016-02-23)
• ​Study in Fiji finds that removing sea cucumbers spells trouble for shallow coastal waters (2018-06-05)
• Earth BioGenome Project aims to sequence genomes of 1.5 million species (2018-04-23)
• Recovery of West Coast marine mammals boosts consumption of chinook salmon (2017-11-20)
• Parasitic plants rely on unusual method to spread their seeds (2017-11-14)
• ​The Interdependence Of Humanity And Earth (2017-11-08)
• Imagining a world without species (2017-09-20)
• What Swims Like a Duck and Quacks Like a Duck Could Be a Hybrid of Two Duck Species (2017-09-11)
• DNA Discovery Reveals Surprising Dolphin Origins (2014-01-11)
• What Do You Get When You Cross a Wolf With a Coyote? (2014-02-28)
• Is the Dingo Special Enough to Save? (2014-03-28)
• Two crows kept separate by their looks (2014-06-20)
• Where did these hybrid fish come from? (2014-07-25)
• 'Weird' Fern Shows The Power Of Interspecies Sex (2015-02-24)
• Chimps and bonobos had flings—and swapped genes—in the past (2016-10-27)
• ​​Microbes can draw the line between species (2013-07-18)
• 'Killer sperm' prevents mating between worm species (2014-07-29)
• Baffling Genetic Barrier Prevents Similar Animals from Interbreeding (2014-08-21)
• ​​Tropical paradise inspires virtual ecology lab (2015-01-14)
• Man's Thriving Garden, Sealed in a Bottle, Hasn't Been Watered in Decades (2016-04-07)
• To Simulate Climate Change, Scientists Build Miniature Worlds (2017-05-11)
• Greening the food pyramid (2014-07-18)
• The Body’s Ecosystem (2014-08-01)
• Life Found 800 Meters Down in Antarctic Subglacial Lake (2014-08-20)
• Hopeful lessons from the battle to save rainforests (TED talk, 2014-10)
• Do gut bacteria rule our minds? In an ecosystem within us, microbes evolved to sway food choices (2014-08-15)
• Scientists and cheesemakers gather for (microbial) culture (2014-08-27)
• There's A Big Leak In America's Water Tower (2014-08-27)
• An ant, a plant, and a bear, oh my (2015-01-05)
• Pythons wipe out rabbits—and probably much more—in Everglades (2015-03-18)
• No Food Fights for Large African Herbivores (2015-06-01)
• The incredible ecosystem of Earth’s hottest spot (2016-1215)
• ​Should We Return The Nutrients In Our Pee Back To The Farm? (2014-07-31)