Question

1. using the food web provided, answer each below: a) how many primary consumers are b) list 2 omnivores: c) list each apex (top of the food chain) d) assume the marsh vegetation represents 1000kj of energy in this ecosystem, and the whale is a tertiary consumer. what amount of that energy in kj would a killer whale expect to receive based on the rule of 10? e) as you go up each trophic level, if only 10% of energy is eaten by the next level, where does the rest of the energy go? f) what organism would be most impacted if the snails were removed from the food web? provide some reasoning.

Explanation:

Step1: Identify primary consumers

Primary consumers eat producers. From the food - web, geese, rats, voles, grasshoppers, snails are primary consumers. So there are 5 primary consumers.

Step2: List omnivores

Omnivores eat both plants and animals. Salmon and rat are omnivores as they consume both plant - based and animal - based food sources in the food - web.

Step3: List apex predators

Apex predators have no natural predators. In this food - web, the killer whale, marsh hawk, and bald eagle are apex predators.

Step4: Calculate energy for killer whale

The killer whale is a tertiary consumer. Energy transfer follows the 10% rule. Producers (marsh vegetation) have 1000 kJ. Primary consumers get 10% of 1000 kJ = 100 kJ. Secondary consumers get 10% of 100 kJ = 10 kJ. Tertiary consumers (killer whale) get 10% of 10 kJ = 1 kJ.

Step5: Explain energy loss

The rest of the energy (90% at each trophic level) is lost as heat during metabolic processes such as respiration, used for an organism's life - sustaining activities like growth, movement, and reproduction, and some is also undigested and excreted.

Step6: Analyze impact of snail removal

Voles would be most impacted if snails were removed. Snails are a food source for voles. Without snails, voles would lose a part of their diet, which could lead to a decrease in their population due to reduced food availability.

Answer:

a) 5
b) Salmon, Rat
c) Killer Whale, Marsh Hawk, Bald Eagle
d) 1 kJ
e) Lost as heat during metabolism, used for life - sustaining activities, and undigested/excreted.
f) Voles. Snails are a food source for voles, and their removal would reduce vole food availability.