Chemistry in Ecosystems Review Worksheet

Ecosystems Review Worksheet

College Chemistry Ecosystems Review Worksheet Advanced 5 Questions 19 Views

Classroom Worksheet

Chemistry in Ecosystems Review Worksheet

Ecosystems Review Worksheet

Name____________________________

Date________________

Score______ / 5

Grade: College

Subject: Chemistry

Topic: Ecosystems

Time: 20 Minutes

Difficulty: Advanced

Questions: 5

Instructions:
Answer all five questions. Show your reasoning where calculations are required. Use complete sentences when explaining concepts. Questions increase in difficulty from 1 to 5.

Skills Practiced:

Ecosystems
Chemistry
Critical Thinking
Problem Solving

1Question

Define the term biogeochemical cycle and name two elements that cycle through ecosystems in this way.

2Question

Explain how photosynthesis and cellular respiration are chemically linked in an ecosystem.

3Question

In a lake ecosystem, fertiliser runoff increases nitrate and phosphate concentrations. Describe one chemical consequence for the water and one biological consequence for organisms in the lake.

4Question

A wetland has a pH of 6.0 after acid rain input. Predict how this change could affect the availability of metal ions such as aluminum and the health of aquatic organisms.

5Question

A forest soil stores 1200 g of carbon per square meter in organic matter. If microbial decomposition releases 3% of this stored carbon as CO2 each year, calculate the annual CO2-C release. Then explain one way ecosystem chemistry could reduce this release over time.

Answer Key

#	Answer
1	A biogeochemical cycle is the movement and recycling of chemical elements between living organisms and the abiotic environment. Two examples are the carbon cycle and the nitrogen cycle.
2	Photosynthesis uses carbon dioxide and water to produce glucose and oxygen, storing energy in chemical bonds. Cellular respiration uses glucose and oxygen to produce carbon dioxide, water, and ATP. The products of one process are the reactants of the other, linking energy flow and matter cycling in ecosystems.
3	A chemical consequence is decreased dissolved oxygen as microbial decomposition of excess algal biomass increases oxygen demand. A biological consequence is eutrophication, which can cause algal blooms that reduce light for aquatic plants and may lead to fish kills because of low oxygen.
4	At lower pH, metals such as aluminum become more soluble and more available in the water. Increased soluble aluminum can damage fish gills and stress other aquatic organisms, reducing growth, reproduction, and survival.
5	Annual CO2-C release = 0.03 × 1200 g C m^-2 = 36 g C m^-2 yr^-1. One way to reduce this release is to increase carbon inputs or stabilize organic matter, such as through greater plant litter production or formation of more resistant soil organic compounds, which can slow decomposition and promote long-term carbon storage.