All of the following are correct about the food chain EXCEPT...

Name: Problem 9, Chapter 5: SAT Biology E/M
Uploaded: 2020-10-13T16:39:15-08:00
Duration: 4 min 53 s
Channel: Hiram Johnson
Description: All of the following are correct about the food chain EXCEPT (A) bacteria and fungi act as decomposers that recycle nutrients (B) producers are always at the bottom of any food chain (C) energy is lost at each trophic level (D) food chains never have more than 4 or 5 trophic levels (E) pesticides tend to be concentrated at the producer level because producers have the largest mass in a food chain

All of the following are correct about the food chain EXCEPT (A) bacteria and fungi act as decomposers that recycle nutrients (B) producers are always at the bottom of any food chain (C) energy is lost at each trophic level (D) food chains never have more than 4 or 5 trophic levels (E) pesticides tend to be concentrated at the producer level because producers have the largest mass in a food chain

All of the following are correct about the food chain EXCEPT
(A) bacteria and fungi act as decomposers that recycle nutrients
(B) producers are always at the bottom of any food chain
(C) energy is lost at each trophic level
(D) food chains never have more than 4 or 5 trophic levels
(E) pesticides tend to be concentrated at the producer level because producers have the largest mass in a food chain

Key Concepts

Biomagnification

Biomagnification is the process by which certain substances, such as pesticides, increase in concentration as they move up the food chain. This occurs because these substances are persistent and accumulate in the tissues of organisms, leading to higher levels in predators than in organisms at the base of the food chain.

Primary Producers

Primary producers are autotrophs, mainly plants and algae, that convert solar energy into chemical energy through photosynthesis. They form the base of the food chain and provide the essential energy that feeds all other trophic levels in an ecosystem.

Energy Flow

Energy flow in an ecosystem follows the movement of energy from one trophic level to the next, generally beginning with primary producers. As energy is transferred, a significant portion is lost as heat due to metabolic processes, which is why energy diminishes at higher trophic levels.

Trophic Levels

Trophic levels refer to the hierarchical stages in a food chain, starting from primary producers at the base, followed by various levels of consumers and culminating with apex predators. Each level represents a different position in the flow of energy and matter within an ecosystem.

Decomposers

Decomposers, including bacteria and fungi, play a fundamental role in ecosystems by breaking down dead organic material and recycling nutrients back into the environment. This process supports nutrient availability for primary producers and helps maintain ecosystem balance.

Transcript

00:01 So basically what we're being asked here is which of the five statements, a through e, is false concerning trophic levels and the food chain.

00:10 I'm going to go with e, and here's why.

00:15 E basically states that because producers, you know, the autotrophs, the plants in an environment, have the most mass, they therefore have the highest pesticide concentration.

00:42 Well, as it turns out, the opposite is true.

00:47 The highest pesticide concentration goes to the predators and the apex predators in an environment because of a wonderful term called biomagnification.

01:08 Underline that, very important, especially if you work with the epa in the 60s or 70s.

01:14 So basically, biomagnification dictates that as you move up the trophic levels, toxins in the environment, toxins in the organisms in the environment increase concentration.

01:39 And here's how we're going to illustrate that.

01:41 So i start off at the producer level, as we always should.

01:45 I'm going to go with a leaf symbolizing the producers.

01:51 Now, let's say that each leaf, there are million leaves, so that's a million drops of pesticide, but each leaf gets, we'll say, one drop.

02:02 Not going to go into milliliters or milligrams.

02:06 So leaf doesn't get any more of these pesticide drops because, as a producer, it makes its own food.

02:14 It doesn't need to consume anything else.

02:16 It doesn't add more pesticide to itself.

02:18 The same cannot be said for the next tier up.

02:22 I'm going to go ahead and draw a little rabbit, a little fluffy tail.

02:28 Little eyes.

02:29 The herbivores have to eat.