Question

name: kouadjo habib
period: 5th
date: 9/5/25
u1l8-13 lions assess. #2 study guide
unit 1 africa - assessment #2
individual (paper)
review for midpoint assessment on tues 09.09.25
lesson 8: how is energy... (partially visible)

(chart/table with columns: (no), organism, amount ingested, amount needed to maintain, amount excreted, whats \missing\?
rows:
organism a: 10.7, 63.0, 30.4, (blank)
organism b: 24.3, 84.0, 42.1, (blank)

questions:

1. what is \missing\ from each organism? what does the \missing\ energy get used for in the organism?
2. if organism b eats organism a, what energy is directly available to organism b from organism a?
3. provide evidence to back up your claim in question #2 (use what we learned in lesson 8 to help you)

Explanation:

Question 1: What is "missing" from each organism? What does the "missing" energy get used for in the organism?

In a food chain or energy flow context, the "missing" energy from an organism (when considering energy intake, energy used for maintenance, and energy passed on) is typically the energy used for cellular respiration (to power life processes like movement, growth, reproduction, metabolic functions) and also includes energy lost as heat (due to the second law of thermodynamics, energy transfers are inefficient). For each organism, the "missing" energy represents the portion of ingested energy that is not stored in biomass (eaten or excreted) but is used for the organism’s own metabolic needs (respiration) and lost as heat.

To calculate the "missing" energy, we can use the energy balance:
\( \text{Energy Ingested} = \text{Energy Needed to Maintain (or Used for Growth/Reproduction)} + \text{Energy Excreted} + \text{Energy Used in Respiration (Missing Energy)} \)

For Organism A:
Ingested = 10.7 (wait, no, looking at the table: Organism A has "Amount Ingested" (maybe? Wait the table columns: (No) [maybe row], then "Amount Ingested", "Amount Needed to Maintain", "Amount Excreted", "What’s Missing?". Wait the numbers: Organism A: Ingested? Wait the columns: Let's parse the table:

• Organism A:
• Amount Ingested: 10.7? Wait no, the numbers: Organism A has 10.7 (maybe Ingested), 63.0 (Needed to Maintain?), 30.4 (Excreted?), then "What’s Missing?". Wait maybe the columns are:

• Amount Ingested
• Amount Needed to Maintain (or Used for Maintenance)
• Amount Excreted
• Amount Used in Respiration (Missing)

Wait, actually, the correct energy flow is: Ingested energy = Energy used for maintenance (or growth/reproduction) + Energy excreted + Energy used in respiration (lost as heat/for metabolism). Wait, maybe the "Amount Needed to Maintain" is the energy used for maintenance, "Amount Excreted" is waste, and "What’s Missing" is respiration. Let's check the numbers.

For Organism A: Let's assume Ingested = Needed + Excreted + Missing. Wait the numbers: Organism A: 10.7 (Ingested?), 63.0 (Needed?), 30.4 (Excreted?), then Missing. Wait that can't be, because 10.7 < 63.0. So maybe the columns are reversed. Maybe "Amount Ingested" is higher. Wait the user’s table:

Looking at the image:

• Organism A:
• Amount Ingested: 10.7? No, maybe the first column is Organism, then Amount Ingested, Amount Needed to Maintain, Amount Excreted, What’s Missing. Wait the numbers: Organism A has 10.7, 63.0, 30.4, and a blank. Organism B has 24.3, 84.0, 42.1, and a blank. Wait that doesn’t make sense because ingested energy should be more than needed + excreted. So maybe the columns are:

• Amount Ingested
• Amount Excreted
• Amount Needed to Maintain
• What’s Missing (Respiration)

Let's recalculate. For energy balance: \( \text{Ingested} = \text{Excreted} + \text{Needed} + \text{Respiration (Missing)} \)

So \( \text{Respiration} = \text{Ingested} - \text{Excreted} - \text{Needed} \)

For Organism A: If Ingested = 63.0, Excreted = 30.4, Needed = 10.7, then Respiration = 63.0 - 30.4 - 10.7 = 21.9

For Organism B: If Ingested = 84.0, Excreted = 42.1, Needed = 24.3, then Respiration = 84.0 - 42.1 - 24.3 = 17.6

So the "missing" energy is the energy used in cellular respiration (to power metabolic processes like breathing, circulation, movement, growth, repair, and reproduction) and is also lost as heat to the environment.

Question 2: If Organism B eats Organism A, what energy is directly available to Organism B from Organism A?

When one organism eats another, the energy directly available to the consumer (Organism B) from the prey (Organism A) is the energy stored in Organism A’s biomass that is ingested by Organism B. This is the energy from Organism A that Organism B can digest and absorb (minus what is excreted as waste). From the energy flow, the energy available to Organism B would be the energy in Organism A that is not used by Organism A for its own respiration or maintenance—i.e., the biomass energy of Organism A (which is the ingested energy minus what Organism A used for respiration, maintenance, and excreted).

From the table, for Organism A: If we consider the energy that is available to be eaten (its biomass), that would be the energy it has stored after meeting its own needs. Using the earlier calculation, Organism A’s biomass (energy available to predators) = Ingested - Excreted - Respiration (Missing) - Needed? Wait no, the biomass is the energy stored in the organism’s body (used for growth/reproduction), which is part of the "Needed to Maintain" or the energy left after respiration and excretion. Wait, in energy pyramids, the energy available to the next trophic level is the net primary production (for producers) or net secondary production (for consumers), which is the energy ingested minus energy used in respiration and excreted.

For Organism A, the energy available to Organism B (if B eats A) is the energy in Organism A’s biomass, which is \( \text{Ingested by A} - \text{Excreted by A} - \text{Respiration by A} \). From our earlier calculation, if Organism A’s Ingested is 63.0, Excreted is 30.4, and Respiration (Missing) is 21.9, then Biomass = 63.0 - 30.4 - 21.9 = 10.7 (which matches the "Amount Needed to Maintain"—maybe that’s the energy used for growth/reproduction, i.e., biomass). So the energy directly available to Organism B from Organism A is the biomass of Organism A, which is 10.7 (the energy Organism A used for its own growth/maintenance, which is now available to Organism B when it eats A).

Question 3: Provide evidence to back up your claim in Question #2 (Use what we learned in lesson 8 to help you)

From lesson 8 (likely about energy flow in ecosystems, trophic levels, and energy transfer), the key concepts are:

1. Energy Transfer Between Trophic Levels: Only a portion of the energy from one trophic level is available to the next. This is because organisms use most of the energy they ingest for their own metabolic processes (respiration) and lose energy as heat, while some is excreted as waste. The remaining energy is stored in their biomass (body tissue), which is what is available to predators.

1. 10% Rule (Approximate): Typically, only about 10% of the energy from one trophic level is transferred to the next, due to energy lost in respiration, excretion, and heat. In our case, Organism A’s biomass (energy available to B) is 10.7, and Organism B’s ingested energy related to A would be this biomass (adjusted for digestion).

1. Energy Balance Equation: The energy available to a predator is the prey’s biomass, which is calculated as \( \text{Prey’s Ingested Energy} - \text{Prey’s Excreted Energy} - \text{Prey’s Respiration Energy} \). From the table, for Organism A, this equals \( 63.0 - 30.4 - 21.9 = 10.7 \), which is the energy stored in A’s biomass (available to B). This aligns with the lesson’s teaching on how energy is transferred between organisms—only the biomass energy (after the prey’s own energy use) is available to the predator.

Answer:

s:

1. The "missing" energy is the energy used in cellular respiration (to power metabolic processes like growth, movement, reproduction, and maintenance) and lost as heat. For Organism A, missing energy = \( 63.0 - 30.4 - 10.7 = 21.9 \); for Organism B, missing energy = \( 84.0 - 42.1 - 24.3 = 17.6 \).

1. The energy directly available to Organism B from Organism A is the biomass energy of Organism A, which is \( 10.7 \) (the energy stored in A’s body after its own respiration, excretion, and maintenance).

1. Evidence:

• From energy flow principles (lesson 8), energy transfer between trophic levels involves losing energy to respiration, heat, and excretion—only biomass energy is available to predators.
• The energy balance equation (\( \text{Ingested} = \text{Excreted} + \text{Maintenance} + \text{Respiration} + \text{Biomass} \)) shows Organism A’s biomass (10.7) is the energy available to Organism B.
• This aligns with the 10% energy transfer rule (approximate), where only a small portion of energy moves between trophic levels, matching the 10.7 energy available from A to B.