What is the term used to describe all of the different populations that live together in an area
Show In the Species, Communities and Ecosystem unit we will look at how almost the entire surface of the Earth is home to organisms of one kind or another. The will see that there are as many as 10 million different species on Earth and understand where and how they live and interact is a branch of biology. We will also look at how humans are not the most numerous species on Earth, but humankind is having a disproportionate effect on the world's ecosystems as damage is caused by pollution, rainforest destruction and global warming. This unit will last 3 class lesons Essential idea:
Nature of science:
Understanding 4.1.U1 Species are groups of organisms that can potentially interbreed to produce fertile offspring.
When two members of the same species mate and produce an offspring it is called interbreeding. Their offsprings it is often fertile. When two different species breed together it is called cross-breeding. This type of breeding happen once in awhile, but the offspring is not fertile, which does not let this to reproduce, because it is infertile. Interbreeding: When 2 members of same species mate
image from Northern Rangelands Trust1000 × 707Search by image 4.1.U2 Members of a species may be reproductively isolated in separate populations.
A population is a group of organisms of the same species that are living in the same area at the same time Members of a species may be reproductively isolated in separate populations Organisms that live in different regions (i.e. different populations) are reproductively isolated and unlikely to interbreed, however are classified as the same species if interbreeding is functionally possible
4.1.U3 Species have either an autotrophic or heterotrophic method of nutrition (a few species have both methods).
Living organisms obtain chemical energy in one of two ways:
4.1.U4 Consumers are heterotrophs that feed on living organisms by ingestion.
Heterotrophs obtain organic molecules from other organisms via different feeding mechanisms and different food sources. Consequently, heterotrophs can be differentially classified according to their feeding pattern
4.1.U5 Detritivores are heterotrophs that obtain organic nutrients from detritus by internal digestion.
4.1.U6 Saprotrophs are heterotrophs that obtain organic nutrients from dead organisms by external digestion.
Saprotrophs secrete digestive enzymes into dead organic matter and digest it externally – absorb products of digestion. Also known as decomposers – they break down carbon compounds in dead organic matter and release elements such as nitrogen into ecosystem so they can be used again by other organisms secrete digestive enzymes into dead organic matter → digest externally → absorb products of digestion
image from website.nbm-mnb.ca 4.1.U7 A community is formed by populations of different species living together and interacting with each other.
Sometimes interaction between two species is of benefit to one species and harms the other (eg parasite and host). Sometimes interaction benefits both species (eg hummingbird and flower – hummingbird feeds on nectar and pollinates it) One species can never live in isolation A group of populations living together and interacting with each other – community
image from digital.wwnorton.com 4.1.U8 A community forms an ecosystem by its interactions with the abiotic environment.
A community is composed of all organisms living in an area. Community of organisms in an area and their nonliving environment – ecosystem is a highly complex interacting system) The system has both abiotic and biotic factors. The organisms depend on the non-living surroundings of air, water, soil, rock. –> abiotic environment. Many interactions take place between organisms and the abiotic environment
4.1.U9 Autotrophs obtain inorganic nutrients from the abiotic environment.
Autotrophs synthesise organic molecules from simple inorganic substances
image from wikipedia 4.1.U10 The supply of inorganic nutrients is maintained by nutrient cycling.
Nutrients refer to the material required by an organism, and include elements such as carbon, nitrogen and phosphorus. The supply of inorganic nutrients on Earth is finite – new elements cannot simply be created and so are in limited supply
4.1.U11 Ecosystems have the potential to be sustainable over long periods of time.
Ecosystems describe the interaction between biotic components (i.e. communities) and abiotic components (i.e. habitat). They are largely self-contained and have the capacity to be self-sustaining over long periods of time There are three main components required for sustainability in an ecosystem:
Skill 4.1.S1 Classifying species as autotrophs, consumers, detritivores or saprotrophs from a knowledge of their mode of nutrition.
Species can be classified according to their mode of nutrition
4.1.S2 Setting up sealed mesocosms to try to establish sustainability. (Practical 5)
Mesocosms: small experimental areas set up as ecological experiments
Making a Self-Sustaining Terrarium 1. Building a verdant foundation
2. Selecting the right plants
3. Maintaining appropriate conditions
This is an interactive map of mesocosm facilities across the world. Click the flags to find out who is doing mesocosm research in each place. 4.1.S3 Testing for association between two species using the chi-squared test with data obtained by quadrat sampling.
(information from BioNinja) If two species are typically found within the same habitat, they show a positive association
If two species tend not to occur within the same habitat, they show a negative association
If two species do not interact, there will be no association between them and their distribution will be independent of one another Quadrat Sampling
Quadrat sampling is not an effective method for counting motile organisms – it is used for counting plants and sessile animals
4.1.4S Recognizing and interpreting statistical significance.
(information from BioNinja)
image from BioNinja Step 1: Identify hypotheses
Step 2: Construct a table of frequencies
image from BioNinja Step 3: Apply the chi-squared formula These
calculations can be broken down for each part of the distribution pattern to make the final summation easier
image from BioNinja Based on these results the statistical value calculated by the chi-squared test is as follows:
Step
4: Determine the degree of freedom (df)
The degree of freedom is calculated from the table of frequencies according to the following formula:
Step 5: Identify the p value
image from BioNinja When df = 1, a value of greater than 3.841 is required for results to be considered statistically significant (p < 0.05)
As the results are statistically significant, the null hypothesis is rejected and the alternate hypothesis accepted:
Key Terms
Classroom Material PowerPoint and Notes on Topic 4.1 by Chris Payne Correct use of terminology is a key skill in Biology. It is essential to use key terms correctly when communicating your understanding, particularly in assessments. Use the quizlet flashcards or other tools such as learn, scatter, space race, speller and test to help you master the vocabulary. Good review video by Mr. Leonard
In The News International-mindedness:
Videos: How many species are there on Earth? In biology, this is one of a fundamental question that we still don’t have a very good answer for. Imagine if chemists didn’t know all the elements of the periodic table, or if physicists didn’t know all of the particles of the standard model. Knowing how many different species there are is information we need to know in order to protect the environment, but it’s a lot harder than you think!
Here’s a neat time-lapse of flesh-eating beetles at London’s Natural History Museum doing some recycling of their own:
For more on how saprotrophs such as fungi can be harnessed to solve pollutant problems, check out Paul Stamet’s talk: 6 ways mushrooms can save the world.
Here’s a nice time lapse showing the breakdown of food by bacteria, fungi and other organisms (nutrients being recyled):
A review of Chi Square with Mr. Andersen. Paul Andersen shows you how to calculate the ch-squared value to test your null hypothesis. He explains the importance of the critical value and defines the degrees of freedom. He also leaves you with a problem related to the animal behavior lab.
What is it called when different populations live together?• A community is formed by populations of different species living together and interacting with each other. • A community forms an ecosystem by its interaction with the abiotic environment. Species: A group of organisms that can potentially interbreed to produce fertile, viable offspring.
What is the term used to describe all of the living and nonliving things that interact in an area?An ecosystem consists of all the living things and nonliving things interacting in the same area.
What is it called when different species live in the same area?September 2020) In ecology, a community is a group or association of populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community, or life assemblage.
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