Answer:
B. Is what the scientists manipulate in the experiment.
Explanation:
The Independent variable is not dependent, or doesn't rely, on another variable in the experiment. So, it would make the most sense that they would manipulate the Independent so that they can watch and see how the dependent variable reacts to the manipulation, or the change, in the independent variable.
Answer: 26.75 meters.
2πr = 84
2 * 3.14 * radius = 84
radius = 84/6.28
r= 13.375
So the diameter will be 13.375 + 13.375 which is 26.75 meters.
It is easier to move through the vanes and hold oxygen better
I hope you meant, a cross between BbPp and BbPp, else for bbpp x bbpp, all the progeny will be bbpp.
We need to work out a Punnett square to determine the genotypes resulting from the cross between BbPp and BbPp. The dyhybrid cross results in 16 different genotypes, of which a few have the same phenotypes.
It can be seen that there are 4 different kinds of phenotypes present, in the ratio 9:3:3:1.
Answer: The greenhouse gas emissions from the extraction of bitumen and the use of large quantities of water.
Explanation:
Bitumen is a natural flammable organic matter formed from kerogen in the process of petroleum generation, which is soluble in carbon disulfide. Asphalt and mineral wax are examples of hydrocarbons which are part of bitumen. Conventional oil is extracted by wells while <u>oil sands deposits are extracted using surface mining sectioning techniques, or are flowed to wells by in situ techniques that reduce bitumen viscosity by steam and/or solvents.</u> So, unlike crude oil extracted in oil wells, bitumen requires an open-pit mining operation, in which large tracts are washed with a mixture of water and chemicals to separate the bitumen from a mixture of sand and clay.
Two consequences of this practice are:
- The greenhouse gas emissions from the extraction of bitumen are larger than the extraction of conventional oil. The emissions produced contribute to enhance the greenhouse effect and cause global warming. The greenhouse effect occurs when certain gases retain part of the energy emitted by the earth's soil when heated by the sun's radiation. This phenomenon occurs naturally, and thanks to it, the average temperature of the Earth is about 14º C (57.2 °F). The problem occurs when these greenhouse gases increase in the atmosphere and the amount of energy that is not released into space also increases and, with it, the Earth's temperature.
- The extraction of bitumen from oil sands requires the use of large quantities of water, and even though water used here can be recycled, only a small amounts is returned to the natural cycle. Also, spills from the transportation of the oil could damage soils and waterways, increasing water pollution. This toxic water could get into surface.
