Science Exam 2 Part 2

Front 1

Describe the role of bacteria and fungi in the carbon cycle.

Back 1

Bacteria and fungi take the C in dead plants and decompose it intohumus in the soil. They also release carbon dioxide during cellrespiration.

Front 2

Identify the reactants and products of photosynthesis and of cellrespiration.

Back 2

Photosynthesis: Reactants are carbon dioxide and water. Productsare glucose and oxygen. Cell Respiration: Reactants are glucose and oxygen. Products arecarbon dioxide and water.

Front 3

Identify the parts of the cell where photosynthesis and cell respirationoccurs.

Back 3

Photosynthesis: in the chloroplasts of plants cells

Cell respiration: in the mitochondria of all cells

Front 4

Describe the function of photosynthesis and in which organisms it occurs.

Back 4

Photosynthesis absorbs energy from the sun and stores it aschemical energy in glucose. It only happens in producers.

Front 5

Describe the function of cellular respiration and in which organisms itoccurs

Back 5

Cell respiration burns chemical energy in glucose and releases it asheat energy to be used by the cell. It happens in all living things.

Front 6

Understand the relationship between photosynthesis and cellularrespiration.

Back 6

Photosynthesis and cellular respiration are reverse reactions.

Front 7

Describe how humans change the balance of the carbon cycle.

Back 7

Humans burn fossil fuels, which releases more carbon dioxide tothe atmosphere.

Deforestation by humans kills trees. This means less trees whichleads to less photosynthesis. This means less absorption of carbondioxide ffrom the atmosphere. Also, burning trees releases carbondioxide to the atmosphere.

Front 8

Explain what a greenhouse gas is and how it is related to humans and thecarbon cycle.

Back 8

A greenhouse gas is a gas which traps heat in the Earth’satmosphere. Carbon dioxide is a greenhouse gas and humans areadding more carbon dioxide gas to the atmosphere through theiractions (see above.)

Front 9

Explain the importance of nitrogen in living things

Back 9

It is found in proteins and DNA of living things

Front 10

Describe the different forms in which nitrogen is found on Earth and whereit is found.

Back 10

Nitrogen gas in the atmosphere

Nitrates and ammonia in the soil and in fertilizers

Protein in plants and animals

Front 11

Describe the role of bacteria and fungi in the nitrogen cycle.

Back 11

Special types of microbes are important to every process in thenitrogen cycle (nitrogen fixing bacteria, decomposing bacteria andfungi, nitrifying bacteria and denitrifying bacteria)

Front 12

Describe the role of legumes in the nitrogen cycle (and give examples.)

Back 12

Legumes have a mutualistic relationship with nitrogen fixingbacteria. They help add nutrients (in the form of ammonia) into thesoil for plants to absorb. Eg. Peas and beans

Front 13

Explain how nitrogen enters the biotic (living) part of the cycle.

Back 13

As mentioned above, nitrogen fixation is the important step of thecycle that allows the abiotic nitrogen gas in the atmosphere to be converted to a form that the biotic part (the producers and then through consumption the consumers) can use.

Front 14

Identify which processes enrich the soil for plants and which processesreturn nitrogen to the atmosphere.

Back 14

Ammonification, nitrogen fixation and nitrification add nutrients tothe soil which can be absorbed by plants. o Denitrification returns nitrogen gas to the atmosphere. Burningfossil fuels releases nitrous oxide ot the atmosphere.

Front 15

Describe similarities and differences between the carbon and nitrogencycle.

Back 15

i am going to leave this one for you to analyze. There are manyacceptable answers.

Front 16

Describe how humans change the balance of the nitrogen cycle.

Back 16

Humans burn fossil fuels which releases nitrous oxide ( agreenhouse gas) into the atmosphere. Humans use excess fertilizer which through runoff ends up in thewater (like oceans and lakes)

Humans dump sewage (which contains nitrogen) into watersources.

Front 17

Explain why an algal bloom forms

Back 17

An algal bloom is a rapid increase in algae in water sources (suchas the ocean.) It happens due to excess nitrogen from humanfertilizers