https://padlet.com/shifakhair/20uo9ajxcp6z Made with panache en-us 2017-03-14 06:30:25 UTC 2025-12-15 15:03:42 UTC hello@padlet.com shifakhair https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884049 MahrahS
Afra 
Dana 
FatimaSF
1. evaporation 
2. condensation 
3. precipitation


]]> 2017-03-14 06:31:29 UTC https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884049 shifakhair https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884081 Nawal, Fatma Salah, Mahra Khalid

https://www.youtube.com/watch?v=nzImo8kSXiU

-burning of fossil fuels and cellular respiration from organisms emit carbon to the atmosphere.
-photosynthetic organisms use CO₂ from the atmosphere for photosynthesis and convert the carbon into organic compounds such as sugar that can be consumed by animals and other consumers.
-decomposition of dead matter releases carbon back into the atmosphere.

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-during photosynthesis, CO₂ is used to make organic molecules such as glucose, which contain carbon and energy. Some of this energy is then consumed and utilized by a consumer, while the other portions of the energy may be used by the photosynthetic organism or may be released as heat.
-After expending that energy by the consumer, the consumer releases remaining energy as heat to the environment and respires. The glucose or organic matter that has been consumed by the consumer is broken down through cellular respiration and the organism then emits CO₂ to the atmosphere. Energy is also lost through excretion.

]]> 2017-03-14 06:32:01 UTC https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884081 shifakhair https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884144 1.Nitrogen fixation:
The conversion of N2 to NH4 by certain organisms known as nitrogen-fixing organisms.
2.Nitrogen uptake:
NH4 is converted to Nitrogen by host cells(Plants, soil etc..)
3.Nitrogen mineralization:
Organic N → NH4+
Decomposers convert nitrogen found in dead bodies to NH4.
4. Nitrification:
Some of the ammonium produced by decomposition is converted to nitrate (NO3-)and it needs oxygen rich environments. Bacteria carry out this to gain energy.
5.Denitrification:
NO3- → N2+ N2O
  Denitrification is the only nitrogen transformation that removes nitrogen from ecosystemsanaerobic process that is carried out by denitrifying bacteria, which convert nitrate to dinitrogen. Nitric oxide and nitrous oxide are gases that have environmental impacts. (NO) contributes to smog, and (N2O) is an important greenhouse gas, thereby contributing to global climate change. ]]> 2017-03-14 06:32:51 UTC https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884144 shifakhair https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884239  Maryam Hamed Alhamed
Alya Saeed
Taif Sulaiman
Rina Saleh

to extract phosphorus
1) weathering occurs when PO43- (phosphate) is added to the soil it leaches either to ground or surface water then reaches the sea that will be taken up by producers, those produces convert phosphorus to biological molecules, consumers eat them and then phosphate is returned to soil when organisms die or decompose.



https://www.youtube.com/watch?v=fWn2rRSvFsM


]]> 2017-03-14 06:34:13 UTC https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884239 shifakhair https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884532
Khawla , Jood , Maha , Fatima Rashed

Potato blight
turns the stalk and stem of potato plants to black slime.caused death of 1million people. caused by phytophthora infestans fungus, and it spreads via airborne spores.
Smallpox
an acute contagious viral disease, with fever and pustules that usually leave permanent scars.


]]> 2017-03-14 06:38:23 UTC https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884532 shifakhair https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884639
- chopping down forests, which leads to loss of habitat for millions of species.
- cars burning off
- greenhouse gases
-  pollution
- waste dumping
- over hunting and fishing.
- industrial gases.

major types (threats) :-
habitat loss, when organisms has no alternative habitat available or species is unable to move, which leads to extinction.
Introduced species, also called non-native or exotic species, are those that humans move intentionally or accidentally from the species’ native locations to new geographic re- gions.
over harvesting
1-Species with restricted habitats for example small island ( seabirds).
2-Also susceptible to over harvesting are large organisms with low reproductive rates for example ( elephants and whales).
Maha, Fatima R, jood, khawla]]> 2017-03-14 06:39:21 UTC https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159884639 https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159888116 2017-03-14 07:16:30 UTC https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159888116 https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159888326 .]]> 2017-03-14 07:18:25 UTC https://padlet.com/shifakhair/20uo9ajxcp6z/wish/159888326