1a - Water and carbon support life on Earth and move between the land, oceans and atmosphere.

Question 1

General importance of water

x6

Answer 1

• life on earth is critically dependent on the abundance of water is all 3 phases-liquid, vapour and ice
• importance of water in its liquid state is appreciated when you consider the lack of liquid water on mars - scientists v excited when they found traces on Mars
• it creates benign thermal conditions as the oceans (71%) - moderate temps by absorbing heat, storing and releasing it slowly
• clouds, that are made of tiny water droplets, reflect 1/5 of incoming solar radiation and reduce surface temps
• water vapour absorbs long-wave radiation which maintains global temps 15 degrees higher than without WV
• makes up 65-95% of all living organisms - growth, reproduction and other metabolic functions

Question 2

Importance of water - Flora

x2

Answer 2

• manufacture their own food and need water for respiration (converts glucose to energy through its reaction with O2, releasing water and CO2 in the process), PS (takes place in the leaves combining CO2, sunlight and water to make glucose and starches) and transpiration
• maintains their rigidity and transports mineral nutrients from the soil

Question 3

Importance of water - Humans and Fauna

x3

Answer 3

• water is the medium used for all chemical reactions in the body including the circulation of oxygen and nutrients
• sweating - water evaporation - cooling process in humans, in animals panting (evaporative cooling)
• water is essential resource for economic activity - used to gen electricity, irrigate crops, provides facilities and satisfy public demand eg drinking, sewage. used in lots of industries eg food manufacturing, brewing, paper and steel making

Question 4

habitable ‘goldilocks zone’?

Answer 4

the ubiquity of liquid water on Earth is due to the distance of the Earth from the Sun - it lies in the so-called ‘goldilocks zone’, which is ‘just right’ for water to exist in its liquid form

Question 5

Importance of Carbon:

x6

Answer 5

• chem element - stored in carbonate rocks eg limestone, sea floor sed, ocean water (dissolved CO2), atmosphere (CO2 gas) and in the biosphere
• life as we know is carbon based; built on large molecules of carbon atoms eg proteins, carbohydrates and nucleic acids
• economic resource - fossil fuels eg coal, oil and natural gas power global economy
• oil also used in manufacturing - plastics, paint and other synthetic fabrics
• agricultural crops and forest trees store carbon for human use eg food, timber, paper, textiles and more
• peat - carbon rich soil

Question 6

significance of importance of carbon

Answer 6

• used to fuel our energy
• needed in everyday life - food/clothes
• we have evolved to rely on carbon - our entire civilisation is built on it
• climate change is disrupting the carbon cycle

Question 7

water and carbon cycles as systems?

open/closed

Answer 7

• global scale - carbon cycle is a closed system driven by the suns energy
• smaller scale - drainage basin/forest ecosystem, material and suns energy cross system boundaries = open system