Because the earth's axis is tilted. ... It is all about the tilt of the Earth's axis. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun in January!
This indicator is an estimate of the amount of space on the earth that an individual uses in order to survive using existing technology. This space includes the biologically productive land and water area that produces the resources consumed by that individual such as food, water, energy, clothing, and building materials. It also includes the amount of land and water required to assimilate the wastes generated by that person. In other words, the ecological footprint measures a person's demand on the bio-capacity of the Earth.
<span>For the first step, you must isolate the cells from the media. The cells contain the DNA so you keep the cells and pellet.
The next step would be a cell lysis which causes the cells to open and the DNA to come out. At this point you would keep the supernatant, as the pellet is the cell membrane and other parts of the cell.
The chelex is to bind to transition metal ions. This would cause and DNases in the cell to become inactive because the metal ion is their cofactor. The pellet in this case would contain the chelex and the DNA would still be in the supernatant.</span>
<span>4. The neurons that carry impulses from the eyes to the spinal cord and brain are called the Sensory neurons. Sensory neurons are nerve cells within the nervous system responsible for converting external stimuli from the organism's environment into internal electrical impulses.
5. Motor neurons carry impulses from the brain and spinal cord to and from the Muscles and glands. The motor neurons transmit impulses from the spinal cord to skeletal and smooth muscles, and therefore directly control all of our muscle movements. There are two types of motor neurons, those that travel from spinal cord to muscle (lower motor neurons) and those that travel between the brain and spinal cord (upper motor neurons)
6. The neuron's cell body has short, branched extensions called dendrites. Dendrites are tree-like extensions at the beginning of a neuron that help increase the surface are of the cell body. They receive information from other neurons and transmit electrical stimulation to the soma (cell body). They are also covered with synapses.
7. In most animals and of different neurons are clustered in bundles called nerves Axons and dendrites. Axon is the elongated fiber that extends from the cell body to the terminal endings and transmits the neural signal. The larger the diameter of the axon, the faster it transmit information. Most neurons have only one axon, they transmit impulses from the cell body and also may or may not have a myelin covering.
8. The insulating membrane that surrounds a single axon in some neurons is called the Myelin sheath. The myelin sheath is a protective covering that surrounds fibres called axons, the long thin projections that extend from the main body of anerve cell or neuron. It is composed of proteins and lipids. The main function is to protect and insulate these axons and enhance their transmission of electrical impulses.</span>