APES Food for thought... Trophic levels
Plants make food during photosynthesis; they are called primary producers or autotrophs. Animals eat
the food. They are known as consumers or heterotrophs.
1. What does the suffix “troph” mean?
It means to nourish
2. What do you think a trophic level is?
Where animals are located on the pyramid
3. How about food chains, food webs? Compare and contrast those terms you learned in biology.
A food chain is a single path throughout the an animal chain, and a food web shows the different connections between different animal groups.
4. Quickly sketch a food chain using organisms that might be found on our school grounds.
a. What do you have to do to turn it into a food web? Do so.
Show different connections between other animals
the food. They are known as consumers or heterotrophs.
1. What does the suffix “troph” mean?
It means to nourish
2. What do you think a trophic level is?
Where animals are located on the pyramid
3. How about food chains, food webs? Compare and contrast those terms you learned in biology.
A food chain is a single path throughout the an animal chain, and a food web shows the different connections between different animal groups.
4. Quickly sketch a food chain using organisms that might be found on our school grounds.
a. What do you have to do to turn it into a food web? Do so.
Show different connections between other animals
5. Look at the following diagrams called Energy Pyramids.
a. What do they all have in common? There all food webs and go from bottom to top
b. How are they different from one another? Each pyramid has different types of animals on each level
7. Two of the pyramids have numbers. Do you see a pattern in the numbers?
a. What might the numbers mean?
1. Calculate the number of gh a hen needs to eat per year.
25 * 365 = 9125 gh
2. How many gh are needed for a year’s supply of hens for you, the farmer?
9125 * 365 = 3330625 gh
3. What is the total mass in kg, of the gh needed to feed all the hens for one year?
3330625/1000 = 3330.625 kg
4. How many kg of soybeans are needed to feed all the gh for one year?
3330625 * 0.3 = 99918.75 kg
5. Sources tell us that Native American Indians ate gh. So you can too! These early Americans could collect about 90 kg of gh per hour, when they were abundant. How many people could the gh feed, compared to the one person that the hen fed? (Perhaps you could dip the gh in chocolate.)
90 * 1000 = 900,000
6. You need to consume 3000 calories/day. If you ate only soybeans how many grams of soybeans would you have to eat per day for calories alone?
3000/3.3 = 909 soy beans
7. Cows produce about 19 kg protein/acre/year and soy produces 200 kg of protein/acre/year.
a. Which is more efficient to eat? Why? The soy is more efficent to eat because the soy produces over 10x the protein a cow does
b. Have you ever eaten a soy burger (veggie burger)? Why or why not?
No, I have never eaten a soy burger because I'm a meat eating type of girl
8. In theory, the earth could support many more people if we ate at a lower trophic level.
a. List 2 benefits of doing this. Less time spent on raising animals before consumption, & healthier food at lower trophic levels
b. List 2 drawbacks of eating lower on the food chain. Less of the organisms in the lower trophic levels, & more of the organisms on the higher trophic levels
10. Large predatory animals can also be problematic to eat because of bioaccumulation and biomagnification of toxins such as lead or mercury in their habitats. What do those two big words mean and why should this be considered when discussing food chains and trophic levels?
Bioaccumulation-The accumulation of a substance in a living organism
a. What do they all have in common? There all food webs and go from bottom to top
b. How are they different from one another? Each pyramid has different types of animals on each level
6. Why are there are more organisms at the base and less organisms as you travel up the pyramid?
a. Any idea what an energy pyramid shows?
There are more organisms at the base because the producers have the most energy. An energy pyramid shows how energy is transferred as it travels through consumers.
a. Any idea what an energy pyramid shows?
There are more organisms at the base because the producers have the most energy. An energy pyramid shows how energy is transferred as it travels through consumers.
7. Two of the pyramids have numbers. Do you see a pattern in the numbers?
a. What might the numbers mean?
The numbers are decreasing by 10%
1. Calculate the number of gh a hen needs to eat per year.
25 * 365 = 9125 gh
2. How many gh are needed for a year’s supply of hens for you, the farmer?
9125 * 365 = 3330625 gh
3. What is the total mass in kg, of the gh needed to feed all the hens for one year?
3330625/1000 = 3330.625 kg
4. How many kg of soybeans are needed to feed all the gh for one year?
3330625 * 0.3 = 99918.75 kg
5. Sources tell us that Native American Indians ate gh. So you can too! These early Americans could collect about 90 kg of gh per hour, when they were abundant. How many people could the gh feed, compared to the one person that the hen fed? (Perhaps you could dip the gh in chocolate.)
90 * 1000 = 900,000
900,000/600 = 1500 people
6. You need to consume 3000 calories/day. If you ate only soybeans how many grams of soybeans would you have to eat per day for calories alone?
3000/3.3 = 909 soy beans
7. Cows produce about 19 kg protein/acre/year and soy produces 200 kg of protein/acre/year.
a. Which is more efficient to eat? Why? The soy is more efficent to eat because the soy produces over 10x the protein a cow does
b. Have you ever eaten a soy burger (veggie burger)? Why or why not?
No, I have never eaten a soy burger because I'm a meat eating type of girl
8. In theory, the earth could support many more people if we ate at a lower trophic level.
a. List 2 benefits of doing this. Less time spent on raising animals before consumption, & healthier food at lower trophic levels
b. List 2 drawbacks of eating lower on the food chain. Less of the organisms in the lower trophic levels, & more of the organisms on the higher trophic levels
c. What are some benefits of being a vegetarian? Less money spent on animals, healthier, & more energy
d. What are some drawbacks? Not having enough nutrients that meat contain, not having enough iron, & not being able to eat meat
9. And then there are fish to eat! Large predatory fish usually are found at the 3rd or 4th trophic level of an energy pyramid. What does this mean in terms of energy loss?
You lose 72.9% of the energy from the lowest level of a trophic pyramid
d. What are some drawbacks? Not having enough nutrients that meat contain, not having enough iron, & not being able to eat meat
9. And then there are fish to eat! Large predatory fish usually are found at the 3rd or 4th trophic level of an energy pyramid. What does this mean in terms of energy loss?
You lose 72.9% of the energy from the lowest level of a trophic pyramid
10. Large predatory animals can also be problematic to eat because of bioaccumulation and biomagnification of toxins such as lead or mercury in their habitats. What do those two big words mean and why should this be considered when discussing food chains and trophic levels?
Bioaccumulation-The accumulation of a substance in a living organism
Biomagnification: Concentrations of toxins in an organism as a result of ingesting other plants or animals
These should be considered, because we are adding toxins in our body by the food we eat. Those toxins can also alter the food chain as it affects the health of those species that absorbed the toxins.
11. Do you think about the food you eat? Why or why not?
I honestly don't think about the food I eat, especially when I'm eating because to me I'm eating to survive and to get the calories I need for the day. I never think about whats bad or good to eat until someone brings it up. Other than that, I don't think about it because I'm too hungry to think during the moment of eating.