GL
Science HW, Week 5-4
Due Friday, March 23rd
Name: ____________________________________________
Date: _______________
Period: _________
TEKS 7.5 B Demonstrate and explain the cycling of matter within living systems such as the decay of biomass in a
compost bin.
Part 1: Review
1. Dominic says that water, H2O, is an organic compound because living things need it. Why is Dominic wrong?
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2. In this unit, we talk about how matter cycles. In your own words, what does it mean to say that matter cycles?
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Part 2: Carbon Cycle
Instructions: Use the diagram of the carbon cycle below to answer the questions.
3. Describe how the element carbon first enters a food web or food chain?
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4. When an herbivore, like a cow, eats a producer, like grass, it consumes many different organic compounds
inside the plant. What is one organic compound found inside plants that is also a product of photosynthesis?
Name of compound:______________________ Chemical formula of compound: ___________________
5. When organisms digest and break down organic compounds, some carbon is breathed out as carbon dioxide
(C02). According to the diagram, what is the name of this process? ___________________________________.
6. When organisms die, the organic compounds in their cells, tissues, and organs are broken down by organisms.
What name is given to organisms that break down and recycle organic matter and give two examples.
Name:_______________________ Example 1: __________________ Example 2: _____________________
Part 3: Nitrogen Cycle
Instructions: Use the diagram of the carbon cycle below to answer the questions.
7. Some species of bacteria can take the nitrogen gas (N2) in the atmosphere to construct other nitrogen
compounds, like nitrate, NO3. According to the diagram, what is the name of this process? ________________
8. What process later replaces nitrogen gas that is removed from the atmosphere? _____________________
9. What process transfers or moves nitrogen compounds from living matter back into the environment?
___________________.
10. Which plant structure absorbs nitrogen compounds from the soil so that the plant can use them? ____________
Part 4: Water Cycle:
Instructions: Use the diagram of the carbon cycle below to answer the questions.
11. What process should fill in box 1?
a. Evaporation c. Condensation d. Precipitation
12. What process should fill in box 2?
a. Evaporation c. Condensation d. Precipitation
13. What process should fill in box 3?
a. Evaporation c. Condensation d. Precipitation