Tuesday, September 18, 2012

Food Chain and Food Web


View Some Examples of Food Chain & Food Web:

Watch the videos about Food Chain:


food chain is a linear sequence of links in a food web starting from a trophic species that eats no other species in the web and ends at a trophic species that is eaten by no other species in the web. A food chain differs from a food web, because the complex polyphagous network of feeding relations are aggregated into trophic species and the chain only follows linear monophagous pathways. A common metric used to quantify food web trophic structure is food chain length. In its simplest form, the length of a chain is the number of links between a trophic consumer and the base of the web and the mean chain length of an entire web is the arithmetic average of the lengths of all chains in a food web.
Food chains were first introduced in a book published in 1927 by Charles Elton, which also introduced the food web concept.

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Watch the video about the Parasitism:

Parasitism is a non-mutual relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host (e.g. Taenia solium). These are now calledmacroparasites (typically protozoa and helminths). Parasite now also refers to microparasites, which are typically smaller, such as viruses and bacteria, and can be directly transmitted between hosts of the same species . Examples of parasites include the plants mistletoe and cuscuta, and organisms such as leeches.
Unlike predators, parasites are generally much smaller than their host; both are special cases of consumer-resource interactions.Parasites show a high degree of specialization, and reproduce at a faster rate than their hosts. Classic examples of parasitism include interactions between vertebratehosts and diverse animals such as tapewormsflukes, the Plasmodium species, and fleas.
Parasitism is differentiated from the parasitoid relationship by the fact that parasitoids generally kill their hosts.[citation needed] Parasitoidism occurs in a similar variety of organisms to that in which parasitism occurs.
Parasites reduce host biological fitness by general or specialized pathology, such as parasitic castration and impairment of secondary sex characteristics, to the modification of host behaviour. Parasites increase their fitness by exploiting hosts for resources necessary for their survival, e.g. food, water, heat, habitat, and transmission.
Although parasitism applies unambiguously to many cases, it is part of a continuum of types of interactions between species, rather than an exclusive category. Particular interactions between species may satisfy some but not all parts of the definition. In many cases, it is difficult to demonstrate that the host is harmed. In others, there may be no apparent specialization on the part of the parasite, or the interaction between the organisms may be short-lived.


Watch the video about the  Commensalism:

In ecologycommensalism is a class of relationship between two organisms where one organism benefits without affecting the other. It compares withmutualism, in which both organisms benefit, and parasitism, when one benefits while the other is harmed.
Commensalism derives from the English word commensal, meaning "sharing of food" in human social interaction, which in turn derives from the Latincum mensa, meaning "sharing a table". Originally, the term was used to describe the use of waste food by second animals, like the carcass eaters that follow hunting animals, but wait until they have finished their meal.


Watch the video about the Mutualism:

Mutualism is the way two organisms of different species biologically interact in a relationship in which each individual derives a fitness benefit (i.e., increased or improved reproductive output). Similar interactions within a species are known as co-operation. Mutualism can be contrasted withinterspecific competition, in which each species experiences reduced fitness, and exploitation, or parasitism, in which one species benefits at theexpense of the other. Mutualism is a type of symbiosis. Symbiosis is a broad category, defined to include relationships that are mutualistic, parasitic, orcommensal. Mutualism is only one type.
A well known example of mutualism is the relationship between ungulates (such as Bovines) and bacteria within their intestines. The ungulates benefit from the cellulase produced by the bacteria, which facilitates digestion; the bacteria benefit from having a stable supply of nutrients in the hostenvironment.
Mutualism plays a key part in ecology. For example, mutualistic interactions are vital for terrestrial ecosystem function as more than 48% of land plants rely on mycorrhizal relationships with fungi to provide them with inorganic compounds and trace elements. In addition, mutualism is thought to have driven the evolution of much of the biological diversity we see, such as flower forms (important for pollination mutualisms) and co-evolution between groups of species. However mutualism has historically received less attention than other interactions such as predation and parasitism.
Measuring the exact fitness benefit to the individuals in a mutualistic relationship is not always straightforward, particularly when the individuals can receive benefits from a variety of species, for example most plant-pollinator mutualisms. It is therefore common to categorise mutualisms according to the closeness of the association, using terms such as obligate and facultative. Defining "closeness," however, is also problematic. It can refer to mutual dependency (the species cannot live without one another) or the biological intimacy of the relationship in relation to physical closeness (e.g., one species living within the tissues of the other species).


Watch the videos that are example Of  Food Web:

food web (or food cycle) depicts feeding connections (what eats what) in an ecological community and hence is also referred to as aconsumer-resource system. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs. To maintain their bodies, grow, develop, and to reproduce, autotrophs produce organic matter from inorganic substances, including both minerals and gases such as carbon dioxide. These chemical reactions require energy, which mainly comes from the sun and largely by photosynthesis, although a very small amount comes from hydrothermal vents and hot springs. A gradient exists between trophic levels running from complete autotrophs that obtain their sole source of carbon from the atmosphere, to mixotrophs (such as carnivorous plants) that are autotrophic organisms that partially obtain organic matter from sources other than the atmosphere, and complete heterotrophsthat must feed to obtain organic matter. The linkages in a food web illustrate the feeding pathways, such as where heterotrophs obtain organic matter by feeding on autotrophs and other heterotrophs. The food web is a simplified illustration of the various methods of feeding that links an ecosystem into a unified system of exchange. There are different kinds of feeding relations that can be roughly divided into herbivory,carnivoryscavenging and parasitism. Some of the organic matter eaten by heterotrophs, such as sugars, provides energy. Autotrophs and heterotrophs come in all sizes, from microscopic to many tonnes - from cyanobacteria to giant redwoods, and from viruses and bdellovibrio toblue whales.
Charles Elton pioneered the concept of food cycles, food chains, and food size in his classical 1927 book "Animal Ecology"; Elton's 'food cycle' was replaced by 'food web' in a subsequent ecological text. Elton organized species into functional groups, which was the basis forRaymond Lindeman's classic and landmark paper in 1942 on trophic dynamics. Lindeman emphasized the important role of decomposerorganisms in a trophic system of classification. The notion of a food web has a historical foothold in the writings of Charles Darwin and his terminology, including an "entangled bank", "web of life", "web of complex relations", and in reference to the decomposition actions of earthworms he talked about "the continued movement of the particles of earth". Even earlier, in 1768 John Bruckner described nature as "one continued web of life".
Food webs are limited representations of real ecosystems as they necessarily aggregate many species into trophic species, which are functional groups of species that have the same predators and prey in a food web. Ecologists use these simplifications in quantitative (or mathematical) models of trophic or consumer-resource systems dynamics. Using these models they can measure and test for generalized patterns in the structure of real food web networks. Ecologists have identified non-random properties in the topographic structure of food webs. Published examples that are used in meta analysis are of variable quality with omissions. However, the number of empirical studies on community webs is on the rise and the mathematical treatment of food webs usingnetwork theory had identified patterns that are common to all. Scaling laws, for example, predict a relationship between the topology of food web predator-prey linkages and levels of species richness.

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View a presentation about the relationship of Food Chain & Food Web(above):

Group Texting Activity:
-Describe distinct characteristics of mushrooms, yeast, and molds that make them different from plants. How do these characteristics help them in their function in the food chain?

-Predict what will happen if some organisms or consumers become extinct.

Answer the survey about the lesson topic:

Rubrics: Tools for Making Learning Goals and Evaluation
Criteria Explicit for Both Teachers and Learners:

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Answer the following question below:


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Rapid Population Growth


See the pictures below - this is the result of the Overpopulation Growth:

Population growth is the change in a population over time, and can be quantified as the change in the number of individuals of any species in a population using "per unit time" for measurement. In biology, the term population growth is likely to refer to any known organism, but this article deals mostly with the application of the term to human populations in demography.
In demography, population growth is used informally for the more specific term population growth rate (see below), and is often used to refer specifically to the growth of the human population of the world.
Simple models of population growth include the Malthusian Growth Model and the logistic model.
Population growth 1800-2011: from 1 billion to 7 billion estimated in 31.10.2011. During the year 2011, according toestimates:
United Nations Population Fund
estimate 31.10.2011
  • 135 million people were born
  • 57 million people died
  • 78 million people increased the world population.

 Watch the video below to know the effect of the over population:

Let's see the two presentation that specify about the Rapid Population Growth below:
Population Growth
Population Growth2

Let's answer the Poll below:
Which you can participate?

Group Texting Activity:
- Go to your municipality or barangay hall and ask if the local government has encountered any problem regarding land(space), water, and food supply in your area. Ask what steps are being done to address those problems. In case no problems have been encountered, ask about their future plans to maintain thier balance.

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Answer the following questions below:

Let's play the game below and have fun:

Make a timeline on Overpopulation:



View some capture images that came from forest that suffer from tropical deforestation:

Deforestationclearance or clearing is the removal of a forest or stand of trees where the land is thereafter converted to a non-forest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use.
About half of the world's original forests had been destroyed by 2011, the majority during the previous 50 years. Since 1990 half of the world's rain forests have been destroyed. More than half of the animal and plant species in the world live in tropical forests.
The term deforestation is often misused to describe any activity where all trees in an area are removed. However in temperate climates, the removal of all trees in an area—in conformance with sustainable forestry practices—is correctly described as regeneration harvest. In temperate msic climates, natural regeneration of forest stands often will not occur in the absence of disturbance, whether natural or anthropogenic. Furthermore, biodiversity after regeneration harvest often mimics that found after natural disturbance, including biodiversity loss after naturally occurring rainforest destruction.
Deforestation occurs for many reasons: trees are cut down to be used or sold as fuel (sometimes in the form of charcoal) or timber, while cleared land is used as pasture for livestock, plantations of commodities, and settlements. The removal of trees without sufficient reforestation has resulted in damage to habitatbiodiversity loss and aridity. It has adverse impacts on biosequestration of atmospheric carbon dioxide. Deforestation has also been used in war to deprive an enemy of cover for its forces and also vital resources. A modern example of this was the use of Agent Orangeby the United States military in Vietnam during the Vietnam War. Deforested regions typically incur significant adverse soil erosion and frequently degrade into wasteland.
Disregard or ignorance of intrinsic value, lack of ascribed value, lax forest management and deficient environmental laws are some of the factors that allow deforestation to occur on a large scale. In many countries, deforestation, both naturally occurring and human induced, is an ongoing issue. Deforestation causes extinction, changes to climatic conditions, desertification, and displacement of populations as observed by current conditions and in the past through the fossil record.
Among countries with a per capita GDP of at least US$4,600, net deforestation rates have ceased to increase.

Watch the videos below to and help our mother Earth:

Watch Juan for his adventure..

Let Us Review!
Answer the questions below:
Deforestation test

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Report Rubrics

Group Texting Activity:
- Research on the newest discoveries in drug preparation. Find out if the forest is an important source of medicine/drugs. Try to explain why.

View a presentation that regards with deforestation(below):

Play & win against the illegal loggers! preserve and defend our forest:

Answer the survey below that's deal with the deforestation:
Poll for our mother Earth

The Oxygen And Carbon Cycles


View some pictures that illustrate the Oxygen & Carbon Cycle:

The Carbon Cycle

plants pull carbon from the air and animals eat the plantsCarbon (C) is the basis of life on Earth. Scientists consider 99.9% of all organisms on the planet to be carbon based life. Those organisms need carbon to survive. Whether the carbon is in the form of a sugar or carbon dioxide gas, we all need it. Unlike energy, carbon is continuously cycled and reused. The Earth only has a fixed amount of carbon. The carbon cycle is the ultimate form of recycling

Start With Plants

Plants are a good starting point when looking at the carbon cycle on Earth. Plants have a process called photosynthesis that enables them to take carbon dioxide out of the atmosphere and combine it with water. Using the energy of the Sun, plants make sugars and oxygen molecules. All of the non-photosynthetic creatures on the planet use the oxygen. Every creature on the planet uses the sugars and starches created by plants. 

Then Animals Eat The Plants

Animals are the non-photosynthetic creatures of the planet. They are not able to create their own food. Instead, they eat plants or other animals. The sugars and starches they eat are broken down by a process of metabolism. The results are energy for the creature, water, and carbon dioxide molecules. The carbon dioxide then returns to the atmosphere where the plants use it again. 

Watch the videos below that help you to know about the functions of Oxygen & Carbon Cycle:
Video related to the oxygen & carbon cycle

View the presentation of this lesson topic:
The Carbon and Oxygen Cycle

Project: Make an illustration of a carbon-oxygen cycle:
science project checklist

Group Texting Activity:
- What does greenhouse effect mean? how does this affect our environment?

Let's Play an exciting game related to this topic:

Let Us Review!
answer the following question below:
Oxygen & Carbon Test