C. All cells arise form previously existing cells. This is because the scraped knee's cells would be replaced by the exact same ones that were removed. Kind of like "Out with the old and in with the new... yet the exact same..!"
Hope this helps!
Answer: The answer is A, organs produce hormones that change a child's body into an adult.
Explanation: The endocrine system is responsible for regulating a range of bodily functions through the release of hormones.
Hormones are secreted by the glands of the endocrine system, traveling through the bloodstream to various organs and tissues in the body. The hormones then tell these organs and tissues what to do or how to function.
Answer: A: Its fertile oases enabled farmers to grow enough food for themselves and for sale.
Explanation: The Arabia region is a region located within the Arabian desert. A desert is an area of extreme heat, often dry weather condition with barren lands that cannot support agriculture and food production. An oases on the other hand is a region of luscious, cultivate-able land within a desert.
Food is one of the most important basic needs of man and hardly can anyone survive without food for more than twenty days. Hence, the presence of oases within the otherwise dry environment of the Arabia region is a major protection against death from hunger.
Taking a closer look at other options, none of them guarantees food supply and income to the Arabia region unlike food production in oases. Hence, the fertile oases is really the most important factor that serves as protection in the region's history.
Correct option: A
The way I'm interpreting this is that what type of bound are these? And yes share electrons in various bonds can share electrons lose and gain, these all sounds like covalent bonds and ionic and hydrogen bounds are from.single to double and to triple bounds.
Consumers/producers: A surplus of consumers and a reduced amount of producers cause an ecosystem to collapse. Their are more mouths to feed then there is food