The promise of jobs and prosperity, among other factors, pulls people to cities. Half of the global population already lives in cities, and by 2050 two-thirds of the world's people are expected to live in urban areas. But in cities two of the most pressing problems facing the world today also come together: poverty and environmental degradation.
Proteins function optimally at a specific temperature. So if you get too hot or too cold, biochemical reactions in your body start to function less well. If the situation becomes extreme enough, they can cease to function well enough to sustain life.
Warm-blooded animals have an advantage over cold-blooded ones in that their bodies automatically try to maintain the optimal termperature for things in their bodies to function. Cold-blooded animals depend on the environmental temperature to do this for them. That's why reptiles are very sluggish when they're cold, but will "wake up" when they get warm.
The cost to this benefit is that metabolically, warm-blooded animals require a lot more fuel to run their bodies. It's very energy-intensive to maintain a constant body temperature. Cold-blooded animals require far less fuel than warm-blooded ones relative to their size.
The way that proteins operate in a specific temperature is also true of the pH in your body which is also very tightly maintained.
Many scientists never wear a lab coat at all. Some work in fields that don't require lab work and do their work behind a computer. Some use their science degrees to teach or write about science. Some work as consultants for companies, or as editors for scientific journals.
Conception is necessary for the continuation of species...for reproduction.
Answer:
Stimulation of thoracic or lumbar spinal regions; impulse reaches chain ganglion; acetylcholine release
Explanation:
