A2 (Half assed)

Question 1

Biogeochemical Cycles

Answer 1

Complex cyclical transfer of nutriets from the environment to organisms and back to the environment

Question 2

Hydrological Cycle

Answer 2

The circular movement of water from the ocean reservoir to the air (cloud), back to the Earth in the form of rain, snow, and finally back to the ocean reservoir via streams and estuaries

Question 3

Evaporation

Answer 3

Liquid to vapor

Question 4

Condensation

Answer 4

Water vapor to liquid

Question 5

Transpiration

Answer 5

Water vapor loss in plant (cooling when hot)

Question 6

Precipitation

Answer 6

Rain / Snow / Sleet / Hail falls to the ground

Question 7

Runoff

Answer 7

More water than land can absorb runs into creek / streams / ponds

Question 8

Percolation

Answer 8

Rain water seeps into soil and filters down

Question 9

What “powers” the water cycle

Answer 9

Solar energy and gravity

• Solar energy causes water to evaporate from the soil, plants, ocean, lakes, streams
• Warm air rises and lifts the water into the atmosphere, where it forms clouds
• Gravity pulls it down again as rain and snow

Question 10

Oxygen Cycle

Answer 10

The oxygen cycle is closely related to the carbon cycle as they are linked by both photosyntehsis and cellular respiration

Question 11

Evidence of an oxygen rich atmosphere

Stromatolites

Answer 11

Dome-shaped rocks composed of thin layers of sediment pressed tightly together.

Formed by photosynthetic cyanobacteria

Cross sections show red-iron bands help reveal what the composition of the ancient atmosphere was like

Question 12

Evidence of an oxygen rich atmosphere

Banded Iron Formations

Answer 12

Thought to have as oxygen produced by cyanobacteria reacted with dissolved iron in the oceans and precipitated out, forming a thin layer on the ocean floor

Question 13

Nitrogen Cycle

Answer 13

1. Bacteria convert N (gas) —> Ammonia via nitrogen fixation
2. Ammonia –> Nitrates to be used by plants
3. Animals can obtain nitrogen by eating plants
4. Excess nitrates in soil –> N (gas) by bacteria (denitrification)

The movement of nitrogen through ecosystems, the soil and the atmosphere

Question 14

Nitrogen Fixation

Answer 14

Nitrogen –> Ammonium

Question 15

Nitrification

Answer 15

Ammonium –> Nitrites by bacteria

Question 16

Assimilation

Answer 16

PLants absorb nitrates into roots

Question 17

Consumption

Answer 17

Organisms eat plants

Question 18

Ammonification

Answer 18

Organisms excrete wastes/dies

Question 19

Denitrification

Answer 19

Nitrate (NO₃) —> Nitrogen (N₂) back into the atmosphere

Question 20

N-fixing bacteria

Answer 20

Convert nitrogen to ammonium for plants and plants provide bacteria with sugars produced via photosynthesis

Question 21

Phosphorus

Answer 21

Key element in ceell membranes, energy releasing molecules, DNA and in calcium phosphate of bones

Question 22

Phosphorus Cycle

Answer 22

• Water gradually releases phosphorus in trapped rocks
• PLants can only use in the form of phosphates (dissolved in water)
• Can be absorbed by phtoosynthesis organisms and enter into food chains
• Can be eroded from rock and carried by water from land to rivers and then to oceans; absorbed by algae (then food chains)
• Organic waste recycled by decomposeres who release phosphates

Question 23

Carbon

Answer 23

The key element o fall organisms from bacteria to humans

- It forms the backbone of many molecules from DNA to proteins to sugars

Question 24

Where do autotrophs absorb carbon from?

IB

Answer 24

The atmosphere

• Carbohydrates
• Lipids
• Carbon containing compounds

Convert it to:

Question 25

Autotrophs ____ the carbon dioxide concentration in the atmosphere

Answer 25

Decrease

Question 26

True or False: Carbon Dioxide is water soluble | IB

Answer 26

- It can remain as a dissolved gas in water - It can combine with water to form carbonic acid (H₂CO₃)

Question 27

Carbonic acid can dissociate to form ____ and _____ ____ | IB

Answer 27

Hydrogen and Hydrogen Carbonate | This lowers the pH of the water

Question 28

Who uses carbonic acid and carbon dioxide | IB

Answer 28

Aquatic plants and autotrophs

Question 29

Autotrophs use carbon dioxide to produce ____ compounds by photosynthesis (or chemosysntehsis) | IB

Answer 29

Carbon | Reduces concentration of CO₂ inside autotrophs ## Footnote Carbon Dioxide diffuses into Autotrophs

Question 30

Carbon moves between organisms and the atmisohere as a result of both ____ and ____ ____ | IB

Answer 30

Photosynthesis, cellular respiration

Question 31

Photosynthesis removes ____ from the atmosphere | IB

Answer 31

Carbon Dioxide (CO₂)

Question 32

Cellular respiration by primary consumers and consumers, including decomposers returns ____ to the atmosphere | IB

Answer 32

Carbon in the form of Carbon Dioxide (CO₂)

Question 33

Any cell that uses aerobic cellular respiration produces ___ ____ | IB

Answer 33

Carbon Dioxide ## Footnote - Non-Photosynthetic Cells (roots in plants) - Animal Cells - Saprotrophs such as fungi

Question 34

Methanogensis | IB

Answer 34

Carbon dioxide is a product of aerobic respiration; Methane is the result of anaerobic respiration

Question 35

Oxidiation of Methane (Formula)

Answer 35

CH₄ + 2 O₂ ➡ 2 H₂O + CO₂ | Naturally oxidzed in the stratosphere

Question 36

Saprotrophs typically digest dead ____ and other _____ _____ | IB

Answer 36

Leaves, Organic Matter

Question 37

Saprotrophs obtain oxygen from | IB

Answer 37

Air spaces in soil

Question 38

Peat

Answer 38

Dark brown acidic material that covoers 3% of land surface ## Footnote - Some environments are waterlogged and therefore use anaerobic respiration ➡ Causes acidic conditions to develop - Saprotrophs cannot survive in acidic conditions or without oxygen readily availible so matter is not fully decomposed

Question 39

Peat becomes ____ (How)

Answer 39

Coal | Peat is under sediment layers; heat and pressure remove moisturue

Question 40

Oil and natural form in ____ below seas and lakes | IB

Answer 40

Mud

Question 41

Organisms have hard body parts made of ____ ____ | IB

Answer 41

Calcium Carbonate | - Mollusc Shells - Hard corals nuild reefs by secreting CaCO₃

Question 42

Limestone is a result of ____ ____ that is deposited by precipitation in the water

Answer 42

Calcium carbonate

Question 43

Two most significant gasses | IB

Answer 43

Carbon Dioxide: - Released by cellular respiration and combustion of biomass and fossil fuels - Removed via photosynthesis Water Vapor: - Formed by evaporation from oceans and transpiration in plants - Removed by rainfall/snow or other forms of precipitation

Question 44

Less impactful greenhouse gases | IB

Answer 44

Methane: - Third most significant - Emitted from marshes, waterlogged habitats, landfills with organic wastes; released during extraction of fossil fuels and melting ice Nitrous Oxide: - Released naturally by bacteria, also released by agriculture and vehicle exhausts

Question 45

A greenhouse gas effect depends on | IB

Answer 45

- Ability to absorb long-wave radiation (the more it absorbs, the larger the effect) - Concentration in the atmosphere (rate that it is released + how long it remains there)

Question 46

Earth absorbs ____-____ energy and then remits it at ____ ____ | IB

Answer 46

Short-wave, longer wavelenghts

Question 47

____-____ radiation is re-emitted towards Earth which ____ the Earth | IB

Answer 47

Longer-wave, warms

Question 48

**True** or **False**: Greenhouse gases can absorb energy at all wavelenghts | IB

Answer 48

**False**: Greenhouse gases can only absorb energy in specific wavelenghts

Question 49

Impact of chaning concentration of greenhouse gases | IB

Answer 49

Dynamic equillibrium is changed and thus the size of its contribution | This could cause global temperatures to rise or fall

Question 50

Milankovitch Cycles | IB

Answer 50

Periodic changes in the orbital characteristics of a planet that control how much sunlight it recieves | Eccentricity (Kepler's First Law - Physics 20)

Question 51

Factors contributing to Earth warming (except GHG's) | IB

Answer 51

1. Milankovich cycles in the Earth's orbit 2. Variation in sunspot activity ## Footnote However, it can also change factors other than climate: - Increased temp = increased evaporation - Increased extreme weather conditions (tropical storms) - Changes to circulating ocean currents

Question 52

At night if the sky is clear, temperatues will ____ quicker than if cloud cover was present | IB

Answer 52

Fall | This is because of water vapor