Photosynthesis is a process used by plants and other organisms to convert light energyinto chemical energy that can later be released to fuel the organisms' activities. This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis, from the Greek φῶς, phōs, "light", and σύνθεσις, synthesis, "putting together".[1][2][3] In most cases, oxygen is also released as a waste product. Most plants, most algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies all of the organic compounds and most of the energy necessary for life on Earth.[4]
Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centresthat contain green chlorophyll pigments. In plants, these proteins are held inside organelles called chloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane. In these light-dependent reactions, some energy is used to strip electrons from suitable substances, such as water, producing oxygen gas. The hydrogen freed by the splitting of water is used in the creation of two further compounds that serve as short-term stores of energy, enabling its transfer to drive other reactions: these compounds are reduced nicotinamide adenine dinucleotide phosphate(NADPH) and adenosine triphosphate (ATP), the "energy currency" of cells.
In plants, algae and cyanobacteria, long-term energy storage in the form of sugars is produced by a subsequent sequence of light-independent reactions called the Calvin cycle; some bacteria use different mechanisms, such as the reverse Krebs cycle, to achieve the same end. In the Calvin cycle, atmospheric carbon dioxide is incorporatedinto already existing organic carbon compounds, such as ribulose bisphosphate(RuBP).[5] Using the ATP and NADPH produced by the light-dependent reactions, the resulting compounds are then reducedand removed to form further carbohydrates, such as glucose.
Negative feedback is a stimulus that cause the system to move in the opposite direction of what has happening. For example if your are cold, you will shiver in order to create heat that will cause your body temperature to increase. But if you are hot you will sweat which will cause your body temperature to decrease.
<span>10% rule (efficiency between trophic levels): limits how long an ecosystem's food chain can be Predator/prey
cost benefit analysis (i.e. foraging) -- cost is risk of being eaten or
killed along the way, benefit is energy/nourishment obtained: limits
distribution of predator v. prey Immigration/Emigration with other populations and ecosystems Island
biogeography: size of land and distance from another
population/ecosystem (mainland): limits population size and variability
on island</span>
I think at Approximately 7 years the child should be able to use each hand independently. Hand control is the ability by a child to accurately use and manipulate objects, utensils, tools and even finger in isolation for functional tsak performance.
