The Food Chain is the sequence of transference of matter and energy … from one living being to another … through food. Green plants are the main source of food … …
The Food Chain is the sequence of transference of matter and energy … from one living being to another … through food. Green plants are the main source of food … and are thus called producer organisms They absorb inorganic compounds present in the atmosphere and soil and transform them into organic compounds in a process known as photosynthesis Herbivorous animals feed on plants … they are the primary consumers! The carnivorous animals feed on the herbivores … they are secondary consumers Organisms that make the decomposition such as fungi and bacteria feed on dead animals and dead plants, decomposing this organic matter and transforming them again into inorganic compounds that feed the plants.
Oops! Excuse me! Oh, hello friends! Have you ever wondered where does the food go, once it enters your body? Sorry! Well, worry no more, cause I’ll tell you all about …
Oops! Excuse me! Oh, hello friends! Have you ever wondered where
does the food go, once it enters your body? Sorry! Well, worry no more, cause I’ll tell you all
about the human digestive system! Oops! Haha! Come on, what
are you waiting for? Zoom in! Digestion is a simple process. Where large insoluble food
particles are broken down.. ..into smaller water soluble molecules. So that, they can be absorbed by blood and
give energy to different parts of our body. The process of digestion has a few stages. And I’ll take you through all of them. Come! Chewing is the first stage
of the digestive system. When you chew your food, the food
particles break down.. ..into little pieces that
are easier to swallow. The saliva which contains a lot of enzymes,
mixes with those food particles.. ..and helps break down those
food particles even more. Once you have completely chewed your food.. ..the tongue helps to push the food
particles down your throat. This process is called swallowing. The food travels through a long pipe
called esophagus.. ..also known as the food pipe. When the food particles,
have travelled through the food pipe.. ..their next destination is the stomach. Where those particles hang out for
approximately four hours. The stomach releases a lot of acids
and enzymes.. ..which further break down
the food particles. So that these particles can be
absorbed by our body. An enzyme called Pepsin
present in the stomach.. ..helps break down the protiens. Oh, and a lot of bacteria are killed
by our super hero, the stomach. So that we don’t fall sick! Destination next!
The small intestine! Once, the food particles reach
the small intestine.. ..a lot of juices from liver and pancreas
help break down those particles. The liver secretes bile,
which helps break down fats. And the pancreas releases other enzymes
to help digest all kinds of food particles. Now that the food particles are
broken down.. ..the small intestine absorbs them and
transfers them to our body through blood. The particles that are not absorbed by the
small intestine, reach the large intestine. Now the large intestine absorbs water
and other particles.. ..and sends the waste material
out of your body! Trivia Time! Did you know that our large intestine
produces.. ..antibodies that helps us boost
our immunity? When your face becomes red
due to blushing.. ..the lining of your stomach
becomes red too! So eat healthy, digest healthy and
live healthy! Tune in next time for more fun facts! This is me Zooming Out!
[INTRO MUSIC] Have you ever had to take out the garbage? Kind of gross, right? But someone’s got to do it. And we’re not the only things that make waste; trees …
[INTRO MUSIC] Have you ever had to take out the garbage? Kind of gross, right? But someone’s got to do it. And we’re not the only things that make waste; trees
drop their leaves and animals drop, well, other stuff. So what happens to all that
waste that’s created in nature? It turns out that waste – as gross as it may seem – is actually a good source of energy
for lots of different living things, like bacteria, some fungi, insects, and worms. These organisms, called
decomposers, break down waste and the remains of dead plants
and animals to get energy. Which is a bonus for the rest of us
because, thanks to decomposers, there’s a lot less waste than dead stuff lying around. Now, if you’ve been paying
attention so far in our little talks here, you’ll remember that all living
things need energy to survive. And energy flows through a system of living things,
moving from plant, to animal, to other animals, in a what-eats-what model called a food chain. We use food chains to see how energy
flows between living things in an ecosystem. So decomposers are living things too, and since
they need energy to live just like anybody else, they need a spot in the food chain. But where do decomposers fit
in an ecosystem’s food chain? Let’s take a look at a simple little ecosystem
to see where they might find a home. Plants like this apple tree are able to
grab the energy that comes from the Sun. They use this energy to take water, nutrients, and a
little bit of gas from the air, to create chemical energy. The tree stashes some of that energy in
its fruit, which happens to be… delicious. If an apple from that tree falls to the
ground and gets nibbled on by a mouse, some of the energy from the apple is
going to be transferred to the mouse, and if the mouse is unfortunate enough to be spotted
by an owl, it’s going to end up as an owl brunch, and the energy from that
mouse will be transferred to the owl. Apple—mouse—owl.
That’s a simple enough food chain, right? Everyone has their place in it – the system works! But decomposers can live and work in
more than one spot in this food chain. They can show up anytime there’s waste to break down, like the leftover apple that the mouse
didn’t eat, or the owl’s droppings. Decomposers break those things down into
smaller parts, like nutrients and other chemicals. These chemicals go into the ground, and are taken up
by plants so they can use them to make more energy, and the process starts all over again. Not to get all ‘Lion King’ on you, but I’m thinking
that this really closes up the circle of life, right? And since we’re talking about circles and cycles,
let’s recycle some of these ideas one last time. Decomposers breakdown waste in an ecosystem into
nutrients, and plants use those nutrients to make energy, and that energy goes up the food chain all over again. And like I mentioned before, decomposers
don’t just put energy back into the food chain, they also keep waste from piling up in an ecosystem. So while we might kind of forget that
insects or worms or fungi are there, remember that we need them to clean up waste. Losing the decomposers in a food
chain would COMPLETELY mess up the nice balance that all living things have going on. Which… okay, yes, I guess means
that I’ll finally clean up my desk. Until next time! [OUTRO MUSIC]
Hi, I am Jared, welcome to Fun Science Demos here on location on the sunny, sandy beaches of Delaware. Take a look, what do you see? It looks like we are …
Hi, I am Jared, welcome to Fun Science
Demos here on location on the sunny, sandy beaches of Delaware.
Take a look, what do you see? It looks like we are
being invaded by horseshoe crabs. Not really. The big idea today is that horseshoe
crabs lay eggs. But that is only part of a bigger story. If
you take a look behind me you will see lots from seagulls and shorebirds. What do you think they are doing? They are
eating. They are looking for food. What are they eating? Horseshoe crab
eggs. So these Red Knots other shorebirds eat
these horseshoe crab eggs. What do they look like? Well, the
horseshoe crabs come up onto the beach where they dig into
the sand and the female horseshoe crabs lay their eggs. What kind of eggs? Take a look. We are
going to zoom in so you can see what horseshoe crab eggs look like. These tiny green eggs are horseshoe crab eggs. Green eggs and sand, all clumped together. These eggs will be buried under the sand
about 10 centimeters, and they are only a few millimeters big.
Some of these horseshoe crab eggs will come to the surface were shorebirds will eat them, and some of the eggs will get washed into the bay where other animals will eat them. And some of the eggs will even turn into
adult horseshoe crabs who will come to the beach and lay more eggs. It kind of seems like everything is
connected, huh? Well, scientists call all of that connectedness the food web. There is a very special
type of bird that makes a long, long trip and that bird needs those horseshoe crab
eggs for the energy to make that trip. What kind of bird is it? The Red Knot. Wonder why they call it the Red Knot? Take a close look. It is red. So what kind of trip does that
Red Knot make? Take a look at this. The Red Knot
starts out in the southern tip of South America, and it flies all the way up to the
Arctic. The Red Knot starts in the southern tip of South America and flies for about 2,000
miles where it makes its first stop. And then it flies 7,000 more
miles until it comes right here in Delaware so it can eat all the
horseshoe crab eggs that are all over this beach. It gets enough
energy to make its final flight up to the
Arctic, 10,000 miles! If you want to learn more about
horseshoe crabs, their green eggs in the sand and shore
birds in the food web, check out our links in the video
description or check out this book, Horseshoe Crabs and Shorebirds: The Story of a Food Web by Victoria Crenson. Science is so cool. So are green eggs and
sand. Thanks for watching.
Hi. It’s Mr. Andersen and welcome to biology essentials video number 47. This is on ecosystems. And we happen to live next to one of the most famous ecosystems on the …
Hi. It’s Mr. Andersen and welcome
to biology essentials video number 47. This is on ecosystems. And we happen to live next
to one of the most famous ecosystems on the plant. That’s the greater Yellowstone ecosystem.
So we live right here in Bozeman, which is about 60 miles north as the crow flies from
Yellowstone National Park. And so when we’re talking about ecosystems we should figure
out where in ecology, what level we’re at. So remember BBECPO is Biosphere, Biome, Ecosystem,
Community, Population, Organism. And so basically what is an ecosystem? An ecosystem is going
to be all of the biotic and abiotic characteristics in an area. And so Yellowstone Park was founded
in 1872. And it was mostly founded to protect these geothermal features. And so what is
most famous would probably be Old Faithful which is about right here. But Yellowstone
is situated on this giant Yellowstone caldera which is kind of like that. And so when they
established Yellowstone Park they established it just to protect the geothermal features.
So the hot springs, the boiling mud and all of that. But what they ended up doing, luckily,
is preserving one of the most pristine ecosystems on our planet. And so Yellowstone Park, if
I look over on this map, if I were to trace it, it’s about right here. So this is right
on the corner of Wyoming and it goes into Montana and Idaho over here. But if you look
at around here there’s all these national forests. And so we eventually have this giant
ecosystem which is kind of in this brownish area. They didn’t really start talking about
it as an ecosystem until the 1970s when they were studying grizzly bears. And they found
that grizzly bears were in trouble. But this was kind of where they ranged. So this was
their range but you can see over here that we’re not sure what an actual ecosystem is.
How big it is. How big we should make that. What’s interesting is that this is all a national
park. And these are national forests around it. But once we move out into here we’re moving
into private land. And so there’s an interesting kind of conflict that comes up when we move
from national lands to land that’s actually owned by people. The wildlife isn’t, but the
land surely is. And so it’s a hard thing to maintain. But even with all of that, greater
Yellowstone ecosystem is the most pristine ecosystem in the northern latitudes. Especially
in North America that we have. So it’s pretty cool. It’s nice to live right next door. So
basically in this podcast I’m going to talk about ecosystems and how they’re effected
by their environment. Remember they get energy from the sun. But the matter has to be recycled.
And so the combination of energy coming in and then the matter, especially carbon being
recycled, we come to a new term here. That’s called primary productivity. So depending
on where you are on the planet you have either a high level or a low level of primary productivity.
Basically what that is is the producers in an area. It’s how much biomass they’re laying
down. As a result of that we have these very complex reactions. And so those are called
food chains. Basically a feeding chain. And if we get more complex that’s called a food
web. But remember every organisms that’s living in an ecosystem is adapted to that environment.
And those specific constraints. Now some times there will be impacts on a ecosystem. And
so those impacts can be biotic or abiotic. Remember they could be living or nonliving.
But basically what that does is create competition. And so all populations are limited by the
amount of availability of these resources that they have. And so eventually all populations
will undergo logistic growth. Now if we let things run naturally, they tend to fit a regular
balance. Or find an equilibrium. But lots of times humans will make changes. And those
changes can have very quick impacts on an ecosystem. And sometimes can lead to extinctions.
And so let’s get started. Let’s first start by defining what primary productivity is.
Primary productivity, as I mentioned just a second ago, is how much livable mass is
being layed down by the producers in their area. Remember the producers are going to
be those things that do photosynthesis. And so they’re using energy. And then they’re
weaving matter together to make life. And so if we look on our planet we find here in
the ocean, we’re going to have, this is measuring the amount of chlorophyll A. We’re going to
have a higher primary productivity here and here then we are right at the equator. And
that has to do with the currents in the ocean. So we need nutrients. And we also need availability
of light. Obviously in the Sahara were not going to have a lot of primary productivity,
but we’re going to have more as we move up into this area. The coniferous forests. For
sure in the rain forests. And so what do we measure primary productivity in? Well it’s
grams of carbon per meter squared per year. In other words if we were to go out in this
prairie and mark one meter. So let’s say one meter area like that, in one year, it’s the
amount of carbon that would be added. Now how’s that carbon being added? We’re taking
in carbon dioxide from the atmosphere. We’re using light from the sun. And then we’re making
it into livable material. And so it’s easy to measure in an area like this. Just put
a quadrant down and measure that. Sometimes it’s hard if you’re in a, this would be a
terrestrial area or ecosystem. This would be an aquatic area. So when you’re in water,
lots of times it’s harder to measure the matter that’s being created. So sometimes well measure
the gases that are being produced. So we can look at the oxygen that’s being produced in
an aquatic environment. So right here we’re going to have higher levels of oxygen being
created because the producers are taking that carbon dioxide and making it into matter.
So primary productivity is going to be just a measure of how much life can be created
in an area. Food chains measure where this life goes. And so if we start here, on the
right side I’ve got what are called trophic levels. And so we should define what a trophic
level is first. Trophic just means an eating level. And so the lowest level, trophic level
one we call that, are going to be producers. And so if we’re looking at a food chain here
in Lake Ontario, what are the producers going to be out in this lake? It’s mostly going
to be algae. So what they’re doing is converting energy from the sun into livable material.
And so we would call this trophic level one. Or sometimes we call these producers. Okay.
So if we go to the next level, the next level, trophic level 2, these are going to be consumers.
And so consumers remember can’t make their own food. They have to get their food from
somewhere else. And so if we were to do a food chain, the food chain’s going to go like
that. Now the arrow, you should get used to, the arrow is always going to go from what’s
eaten to what eats it. And the way I remember this is if you look at the head of the arrow
it’s like the mouth. So it’s like the mouth of PacMan. And so whatever is eating is going
to be on this side of the arrow. And whatever is eaten is going to be on that side of the
arrow. So now we go to the third level. The third level is going to be, we call these
second level consumers. But those are going to feed on these organisms. So algae is eaten
by amphipods, which are a little crustacean. Those are fed on by rainbow smelt. And then
if we were to go one more level, then we get to the level of chinook salmon. So this would
be the fourth trophic level or we’d call this a third level consumer. Now this is a food
chain. Food chains are linear. They go from what’s eaten, to what eats it. To what eats
that. To what eats that. So it just goes in one direction. But you can imagine that there’s
a lot more food chains in Lake Ontario then the one that I’ve just drawn here. And so
if we were to add the other food chains, now we get what’s called a food web. A food web
is going to show all the connections. Not only this one, to amphipods to the rainbow
smelt to chinook salmon, which I think were actually introduced into Lake Ontario. But
it’s also going to show the flow of perch to walleye. It’s going to show all these interactions.
And in any ecosystem this is a fairly simple food web. It’s just showing the major ones.
Obviously if we were to include all the different types of algae, this would be a massive food
web. And so in an ecosystem there’s all these connections between the organisms. And it’s
pretty detailed. Now each of those have adaptations that allow them to live where they are. In
other words the green algae are adapted to this kind of an environment. Same with the
diatoms. Okay. Next thing I need to talk about is growth. And we’ve mentioned this when we
talked about communities and how populations grow. In general, all growth is going to be
exponential. So if we were to go with amphipods, they’re going to create more amphipods and
eventually we get exponential growth. I could use a color that you could actually see. So
we get exponential growth like that. But the problem is as you start to grow there start
to be limiting factors. Pretty soon you’re too crowded. There’s not enough food. There’s
competition. There’s also going to just be drought. There’s going to be meteorological
geological changes that can limit that growth. And so all growth will eventually become logistic.
In other words it’s eventually going to reach what we call a limit. In science we call that
K or K stands for carrying capacity. So carrying capacity is going to be the maximum level
that an ecosystem can support of a specific population. Now it’s not going to be linear
like this. This is just using a mathematical representation. Obviously populations are
going to bounce up and down. And they’re going to bounce up and down on this carrying capacity.
But in general all populations will undergo that. Let’s look at some real populations.
So wolves were reintroduced into Yellowstone Park in 1995. So they put some packs there.
This is actually a picture of one of the first wolves coming out of the enclosure. They brought
them from Canada. And they left them in an enclosure for months if I remember because
they didn’t want them just to run back to Canada. So they eventually released them.
And let’s look at what their population has grown. So blue is all the wolves in Yellowstone
Park. And then the other two bars are just in different areas. But if we look at the
population growth, population growth has varied a little bit. But it’s gone up and down and
up and down and up. And so what’s it doing? Well you can see that this part was more exponential
growth. And now it’s approaching what’s called logistic growth. In other words there’s just
a certain number of wolves you can actually support in Yellowstone Park. If we were to
draw in what the K value is, I would say K value so far looks like right about here.
Maybe around 140, 150 wolves that Yellowstone Park can support. Now the wolves are moving
outside of the park as well. There’s competition that happens then. So this is the same thing.
Here is that growth of wolves. So the wolves are going to be on this side. So their population
went up. They’ve gone down, up, down. It will probably go up. So it’s just going like that.
So on this side we’ve graphed the wolves. But let’s look at what has happened to the
elk population. So the elk population is going to be listed on the other side. Something
like 87% of what wolves eat are elk. So these two are linked together. They eat bison. They
eat moose. They eat a lot of different things. But in general they’re mostly eating elk.
And so if we look at what’s happened to the elk population during this time, the elk populations
started at around, this is in the northern are of Yellowstone Park. They started around
16,000 but it’s steadily dropped off. Okay. So now it’s down to who knows, 5000 elk. Maybe
in 2011. So what pressure is that going to put on wolves? Well now there’s not a lot
of food to eat. And so the wolf population is going to drop off. As the wolf population
drops off, they’re going to feed on less elk. And so there’s probably going to be the predator-prey
relationship between the two, where the elk population will start to make a comeback.
It’ll drop off like that. And then if we look at the wolf population, wolf population is
going to follow that as well. And so we reach what’s called an equilibrium. Now this is
great for wolves, not great if you’re an elk hunter in Montana. Because the population
has gone from 16,000 down to like 5,000. And so as they move out of Yellowstone Park, as
wolves move into that area that’s private, like I mentioned at the beginning, there get
to be real human issues and impacts with that. Last thing that I want to talk about relates
to humans then. So humans can have huge impacts on an ecosystem and not knowingly we an make
big changes. So let tell you the story of the whitebark pine. Whitebark pine is going
to be found in Yellowstone Park. If we look at where it is, here’s present day whitebark
pine. So it’s usually going to be found in higher areas. But basically it’s a sturdy
kind of a pine that can deal with lots of snow and really cold temperatures. But they’ll
produce pine nuts during the year. And those pine nuts are gathered up by squirrels. So
the squirrels love to grab the pine nuts. They dig and create these middens which are
just like a stash of a bunch of these pine nuts. They’ll feed on those during the winter.
But sometimes they forget where they are. And a lot of the time those middens are, middens
m-i-d-d-e-n-s, are raided by grizzly bears. So grizzly bears will move up into these areas.
And they’ll raid these middens. And so it’s a big part of their food supply before they
start to hibernate in the winter. And so what’s happening? Well global warming, so changes
to the global climate or climate change, is creating warming conditions in Yellowstone
Park. And this is projections of what will happen to the whitebark pine population if
we just get a moderate increase in temperature. They can’t deal with that. And so the whitebark
pine is going to drop off. As a result of that, squirrels aren’t going to have any nuts
that they can actually stash. Grizzlies aren’t going to have that. And so you can see that
this food chain is tied to the environment. Tied into, in this case it’s going to be the
overall temperature. And so human impacts are so fast. So global climate change is so
fast that is forces pressure on all the species within that ecosystem and all those connections.
A lot of the ones we don’t even know. And so that’s ecosystems. They’re really delicate.
They also have feedback loops that kind of maintain that equilibrium. But I hope that’s
>>I FEEL JOAN CARTAN-HANSEN, AND WELCOME TO SCIENCE TREK: THE WEB. WELCOME TO ZOO BOISE. JOINING ME TODAY TO ANSWER YOUR QUESTIONS ABOUT THE FOOD WEB ARE DR. HOLLY HOLMAN AND …
>>I FEEL JOAN CARTAN-HANSEN, AND WELCOME TO SCIENCE TREK: THE WEB. WELCOME TO ZOO BOISE. JOINING ME TODAY TO ANSWER YOUR QUESTIONS ABOUT THE FOOD WEB ARE DR. HOLLY HOLMAN AND ADARE EVANS.>>GLAD I COULD BE HERE, THANK YOU.>>THANK YOU VERY MUCH.>>OK. LET’S GO TO YOUR QUESTIONS.>>HI, I AM TARA, AND I GO TO BASIN ELEMENTARY SCHOOL, AND MY QUESTION IS, WHAT IS THE BIGGEST TOP PREDATOR?>>WELL, AGAIN, I THINK THAT YOU HAVE TO LOOK TO THE OCEAN. SO, WHALES WOULD BE THE BIGGEST TOP PREDATOR, SOME OF THE WHALES EAT THINGS LIKE PLANKTON OR KRILL, WHICH ARE TINY ORGANISMS THAT FLOAT AROUND IN THE OCEAN, AND OBVIOUSLY, THEY ALSO FEED ON FISH AND OTHER MARINE LIFE. SO, THE WHALES WOULD BE THE KINGS OF THE OCEAN WHETHER IT COMES TO PREDATORS.>>COURTNEY WOULD LIKE TO KNOW WHERE ARE BEARS IN THE FOOD WEB?>>THRILLED BE AT THE DON’T. AT LEAST WHEN YOU THINK ABOUT MOST CHAINS, SO IN IDAHO WE HAVE BLACK BEARS AND WE HAVE GRIZZLY BEARS. AND BOTH OF OUR BEARS, ACTUALLY, MOSTLY EAT PLANTS RATHER THAN ANIMALS. SO, IF WE THINK ABOUT A BEAR LIKE A BLACK BEAR, THEY COULD EAT THAT BLUEBERRY OR THE HUCKLEBERRY THAT THEY FIND, AND DHAKD BE THE END OF IT. THE REASON THAT WE KIND OF THINK OF THEM BEING AT THE TOP IS BECAUSE THIS REALLY ISN’T VERY MANY THINGS THAT ARE GOING TO EAT A BEAR. PEOPLE DO HUNT BEARS. SO, THERE MIGHT BE AN OPPORTUNITY FOR A PERSON TO EAT A BEAR THAT WAY. BUT REALLY, THERE IS NOT VERY MANY ANIMALS THAT ARE GOING TO KILL A FULL SIZED GROWN BEAR.>>I AM BREE, AND I AM FROM GALILEO ACADEMY, AND MY QUESTION IS — WHY DO WE HAVE FOOD WEBS.>>I THINK THAT WE HAVE THE FOOD WEB JUST TO SHOW HOW THE ENVIRONMENT IS INTERCONNECTED WITH ALL OF THE ANIMALS AND ALL OF THE PLANTS AND THE SUN AND ALL OF THE NUTRIENTS TOGETHER.>>I THINK FOOD WEBS ARE IMPORTANT BECAUSE IT DOES HELP TO SHOW US HOW EVERYTHING IS CONNECTED IN THE ENVIRONMENT, AND IT CAN ALSO HELP TO SHOW US IF SOMETHING GOES WRONG, WHERE DID IT GO WRONG. SO, IT CAN HELP US REALLY DETERMINE WHETHER AN ENVIRONMENT IS HEALTHY, IF WE NOTICE ONE ANIMAL IS STRUGGLING, WE NEED TO LOOK AT WHAT IT EATS, AND THAT MIGHT POINT US IN ANOTHER DIRECTION WHERE WE NEED TO FOCUS ON ENERGY AND TIME, TO SEEING HOW WE CAN MAKE THE WHOLE WORLD OR THE WHOLE ENVIRONMENT A HEALTHIER SYSTEM, AND LOOKING AT THE FOOD CHAINS AND THE WEB CAN HELP US TO DO THAT.>>HELLO, I AM ISAIAH. THE SCHOOL I AM AT IS BASIN ELEMENTARY. MY QUESTION IS, IS WHY DO OTHER ANIMALS EAT EACH OTHER?>>WHY DO ANIMALS EAT EACH OTHER? BECAUSE THEY ARE HUNGRY. ANIMALS NEED FOOD, JUST LIKE WE NEED FOOD. AND SOME ANIMALS ARE DESIGNED TO EAT OTHER ANIMALS. IF WE LOOK AT SOMETHING LIKE A BAT THAT LIVES IN IDAHO, LIKE A HORE BAT, THEY EAT INSECTS. TO YOU THAT DOES NOT SOUND APPETIZING, BUT TO THE BAT, THAT’S YUMMY, AND THEY LOVE TO EAT MOTHS. AND BY THAT BAT, EATING THE MOTHS, IT, ACTUALLY, HELPS TO KEEP THE ENVIRONMENT REALLY HEALTHY BECAUSE THAT MOTH MIGHT BE A CERTAIN MOTH THAT MAY BE WOULD ATTACK THE EAR OF CORN THAT YOU REALLY LIKE TO MUNCH ON. SO, BY THE BAT EATING THE MOTH, IT KEEPS EVERYTHING NICE AND HEALTHY, AND THAT LITTLE MOTH GIVES THE BAT WHAT IT NEEDS TO BE ABLE TO SURVIVE.>>HELLO. I AM BRENDON, AND I AM FROM BASIN ELEMENTARY. MY QUESTION IS, DOES THE FOOD CHAIN GO ON FOREVER?>>DOES THE FOOD CHAIN GO ON FOREVER? EVERYTHING HAS TO COME TO AN END. IF WE THINK ABOUT A FOOD CHAIN, YOU COULD END YOUR FOOD CHAIN AT THE TOP, AS A TOP PREDATOR, BUT I LIKE TO TAKE IT ALL THE WAY DOWN, SO WE HAVE SOMEBODY THAT EATS ANOTHER ANIMAL, AND THEY DIE, AND SCAVENGERS WILL PICK UP THE BITS AND PIECES, AND FOR ME A FOOD CHAIN ENDS WHEN THAT ANIMAL IS COMPLETELY DECOMPOSED BACK INTO THE SOIL. SO, I SUPPOSE IT KIND OF DEPENDS ON YOUR DEFINITION OF HOW FAR YOU WANT TO TAKE YOUR FOOD CHAIN. FOR ME, IT DOES NOT HAPPEN UNTIL THAT ANIMAL IS COMPLETELY DECOMPOSED, AND THEN IT WOULD COME TO AN END.>>HELLO, I AM MOLLIE, AND I GO TO GALILEO STEM ACADEMY, AND MY QUESTION IS, HOW MANY ANIMALS CAN FIT ON A FOOD WEB?>>AS MANY AS YOU CAN IMAGINE. A FOOD WEB CAN BE AS SMALL OR AS COMPLICATED AS YOU WANT IT TO BE. REMEMBER, THAT IT’S GOING TO INVOLVE ALL THE ANIMALS AND PLANTS AND ENERGY SOURCES THAT WOULD PROVIDE NUTRIENTS IN A CERTAIN ENVIRONMENT, SO HOW LARGE YOUR ENVIRONMENT IS, IS HOW BIG THE FOOD WEB COULD BE.>>KATE WOULD LIKE TO KNOW, SHOULDN’T THE SUN BE IN THE FOOD CHAIN BECAUSE PLANTS GET ENERGY FROM THE SUN.>>MY ANSWER WOULD BE YES. YOU CAN’T HAVE A FOOD CHAIN UNLESS YOU HAVE SOME SOURCE OF ENERGY. SO, IT WOULD BE THE SUN OR SOME OTHER SOURCE OF ENERGY WHERE ANIMAL OR A MIKE ROPE IS GETTING THEIR FIRST BIT OF ENERGY FROM.>>IS THERE ANYTHING ELSE IN ENERGY BESIDES SUNLIGHT?>>WHEN WE LOOK AT THE DEEP OCEAN, NO SUN CAN REACH THE OCEAN FLOOR. AND SO, THERE IS FOOD CHAIN AND IS WEBS THAT HAPPEN VERY DEEP IN THE OCEAN, AND WHERE THOSE PARTICULAR FOOD CHAINS AND WEBS START IS VERY, VERY DEEP SEA VENTS, AND IN THESE SEA VENTS, THEY KIND OF SPEW OUT AND LOOK LIKE MINI VOLCANOS IN THE WATER, AND THEY SPEW OUT ALL OF KNEES MINERALS AND CHEMICALS, AND DOWN DEEP IN THE OCEAN, THERE ARE THESE TINY BACTERIA THAT EAT THE CHEMICALS. AND THE MINERALS. AND THEN THERE ARE ZOE PLANKTON, THESE TINY ORGANISMS THAT EAT THE BACTERIA, AND THEY ARE THE START OF THE FOOD CHAINS AND THE WEBS IN THE OCEAN. SO, IT’S NOT ONLY THE SUN THAT CAN START THE FOOD CHAINS AND THE WEBS, BUT ALSO THE DEEP SEA VENTS THAT SPEW OUT THE CHEMICALS.>>HI, I AM ELLIE. I GO TO GALILEO STEM ACADEMY. I HAVE A QUESTION. ARE FOOD WEBS IMPORTANT?>>YES. FOOD WEBS ARE IMPORTANT BECAUSE THEY SHOW US THE INTERCONNECTION BETWEEN ALL THE LIVING ANIMALS AND PLANTS THAT ARE IN OUR ENVIRONMENT.>>I AM SORRY, WE HAVE RUN OUT OF TIME. MY THANKS TO HOLLY AND ADARE FOR ANSWERING QUESTIONS TODAY.>>THANKS.>>IT HAS BEEN FUN. THANK YOU.>>THANKS, TOO, TO THE FOLKS AT ZOO BOISE FOR HOSTING US. IF YOU WANT TO LEARN MORE ABOUT THIS TOPIC, CHECK OUT THE FOOD WEB AREA ON THE SCIENCE TREK WEBSITE. YOU WILL FIND FACTS, LINKS, AND GAMES, OUR FOOD WEB BROADCAST SHOW, AND LOTS MORE. AND EVERY WEEK, CHECK OUT MY BLOG. FOR THE LATEST SCIENCE NEWS FOR KIDS. ALL THAT AT IDAHOPTV.ORG/SCIENCETREK. THANKS FOR JOINING US. FOR SCIENCE TREK: THE WEB.
Welcome to MooMooMath and ScienceAll living things need energy. Some biotic factors get their energy from the sun. Others eat other biotic factors As a result energy flows in ecosystems. This …
Welcome to MooMooMath and ScienceAll
living things need energy. Some biotic factors get their energy from
the sun. Others eat other biotic factors
As a result energy flows in ecosystems. This flow of energy can be represented with
food chains and food webs. For most ecosystems the ultimate energy source
is the sun As you move from one organism to another you
move up trophic levels. For example moving from the mollusk to the
white perch would be a trophic level Producers which use photosynthesis to create
their energy are a large source of energy in an ecosystem. Plants and algae are examples of producers. As consumers eat these producers, carbon bonds
are broken and energy is released and this energy is transferred from one level to another. As you move from one trophic level to another
you lose 90 percent of the energy. This is known as the 10 percent rule. For example if you start with 1000 Joule and
a grasshopper eats the plants only 10 Joule will be transferred, and a bird eats the insect
on 1 Joule will be transferred Where does this energy go? Most of the energy is lost as heat
The energy flow in an ecosystem follows the laws of thermodynamic
The first law states that states that energy cannot be created or destroyed in an isolated
system however it can be converted from one form to another The second law states that this energy conversion
is never completely efficient. As a result, most energy is lost as heat. So there you go. The energy flow in an ecosystem
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So, we have three different ecosystem roles that we discussed so far. We have our producers which do photosynthesis, our consumers which do cellular respiration, and also our decomposers which are …
So, we have three different ecosystem roles that we discussed so far. We have our producers which do photosynthesis, our consumers which do cellular respiration, and also our decomposers which are also undergoing cellular respiration. And again, as a note, plants or producers undergo cellular respiration as well. But they do photosynthesis whereas the others don’t. But how do those organisms interact in the ecosystem? So we’ll talk a little bit about food chains, and a lot of this is probably review of basic concepts you may have learned a long time ago, but I want to get everyone on the same page. So here we have a food chain, or more specifically, this is called a trophic pyramid, just by the way that it’s represented. But it’s still showing the same kind of information, you got these guys eating these guys, which are eating these guys. That word trophic essentially means feeding level. So this is the feeding level each of these organisms are at. So we have our producers, and our consumers, but as you can see our consumers are numbered based on where they are in the food chain. So we have primary consumers, secondary consumers, and so on. It’s also pyramid shaped and we’ll talk about why that is in a little bit. But the fact that this is a pyramid is actually significant. So let’s talk about each of the different steps of this trophic pyramid. At the very bottom are the producers. They get their energy from the sun through the process of photosynthesis. This includes, you know, grasses, trees, don’t forget that algae in the ocean, even some types of bacteria are photosynthesizers. This is also the largest part of our trophic pyramid. And as you could see in the earlier image, the trophic pyramid started with the producers. All trophic pyramids, no matter where, will start with producers and really all our energy comes from the sun ultimately. So as I mentioned before, just because you don’t like fruits and vegetables doesn’t mean you’re not getting your energy from them. Somewhere along the way producers are fueling the rest of this trophic pyramid. This will become more pertinent a little bit later, but you can also shorthand producers with a P and when we go to labeling a food chains and food webs that P matters. The next step up are our primary consumers, so they are consumers, so they’re eating something else. Primary referring to they’re the first consumers in the food chain. These guys are our herbivores. They are eating all of the producers, so since they are only eating plant matter, only eating fruits and vegetables, that is why they’re herbivores. This primary consumer can be short-handed with a 1 and then this little degree symbol this means primary. And this is a way to short-hand it because, again, that will be more important later on. But some examples, you know, we got ants, spiders, moths, rats, a lot of insects are primary consumers. All right the next rung up our secondary consumers. These guys are feeding on primary consumers. You can kind of see a trend here. They can be carnivores because they’re just eating a primary consumer. They could also be an omnivore, maybe they’re eating both. So humans kind of fall here. You know, here’s us maybe you eat a cow, and then the cow is eating grass. Or you’re eating a chicken, chicken eats corn, or you’re eating sheep, sheep eats grass, and most of the meats that we eat are primary consumers which makes us a secondary consumer. But in some respects, we’re still a primary consumer. When we eat a salad, when we are eating you know almonds, we’re eating a producer, so this is a key note: organisms can be and more than one. Just because you’re a secondary, excuse me, just because you’re a secondary consumer doesn’t mean you can’t be a primary consumer. You can fit into more trophic tiers in the trophic pyramid. It’s not you’re just one and that’s it. It really depends on what you’re eating. And then we can keep going up, we have tertiary, tertiary would be the three degree. Quarternary, this would be the four and the degree and these guys are just eating secondary consumers or they’re eating tertiary consumers. You could go up to five, six, seven, but pyramids and food chains usually don’t get that high. We’ll talk about why in a little bit. So you’re really not going to see like a ten-ary level and maybe you might see, at most six, but most of the food pyramids, or trophic pyramids, you’ll see in this class might end it like five. You don’t really need to know the names, as long as you can shorthand it to this 3 4 5 etc., you’re fine, but again they’re eating on the tier below them. The reason this is a quarternary consumer is because one of the foods that its eating is a tertiary consumer. But something you may have noticed, I didn’t cover all the ecosystem roles. I talked about producers, and I talked about consumers but we’re missing one. Which one are we missing? Well we’re missing those detritivores, those decomposers. Where are the vultures in that? Where were the fungi and the worms? You’ll never see them in a food chain, you’ll never see them in a trophic pyramid, because they’re everywhere. All over the place in a food chain, or in a trophic pyramid. They still serve incredibly important functions though. One they remove the remains of organisms, so you don’t have carcasses laying everywhere on the forest floor or in a grassland. So one of the things they do is they’re just checking up old material. In that process of breaking up that old material breaking up those bones that no other animals can eat, you know, breaking down those tissues that things just don’t consume, they’re actually recycling the nutrients that was in that bone, in that muscle, in that fur. The nutrients that made up that tissue are actually going back into the soil, that’s serving as nutrients for more producers, and those producers will get consumed, and those consumers will die and they’ll decompose, and you get the gist. So decomposers, if I look back at this trophic pyramid, they’re everywhere. You know, when a secondary consumer dies a decomposer eats it; when a primary consumer dies a decomposer eats it; when a quarternary consumer dies a decomposer eats it. So that’s why decomposers aren’t found on a trophic pyramid because they’re eating things when they die. It doesn’t matter what level it was at, it’s dead organism. They’re not hunting a tertiary consumer. They’re just taking advantage that a tertiary consumer has died and now it’s breaking it down. So although not pictured in that trophic pyramid still incredibly important and it kind of maintains this structure.