Explanation: Fireflies produce a chemical reaction inside their bodies that allows them to light up. This type of light production is called bioluminescence. The method by which fireflies produce light is perhaps the best known example of bioluminescence. When oxygen combines with calcium, adenosine triphosphate (ATP) and the chemical luciferin in the presence of luciferase, a bioluminescent enzyme, light is produced. Unlike a light bulb, which produces a lot of heat in addition to light, a firefly's light is "cold light" without a lot of energy being lost as heat. This is necessary because if a firefly's light-producing organ got as hot as a light bulb, the firefly would not survive the experience.
A firefly controls the beginning and end of the chemical reaction, and thus the start and stop of its light emission, by adding oxygen to the other chemicals needed to produce light. This happens in the insect's light organ. When oxygen is available, the light organ lights up, and when it is not available, the light goes out. Insects do not have lungs, but instead transport oxygen from outside the body to the interior cells within through a complex series of successively smaller tubes known as tracheoles. For a long time it was a mystery as to how some firefly species manage such a high flash rate, considering the relatively slow speed of the muscles that control oxygen transport. Researchers fairly recently learned that nitric oxide gas (the same gas that is produced by taking the d rug Viagra) plays a critical role in firefly flash control. In short, when the firefly light is ¿off," no nitric oxide is being produced. In this situation, oxygen that enters the light organ is bound to the surface of the cell's energy-producing organelles, called the Mitrochondria, and is thereby not available for transport further within the light organ. The presence of nitric oxide, which binds to the mitochondria, allows oxygen to flow into the light organ where it combines with the other chemicals needed to produce the bioluminescent reaction. Because nitric oxide breaks down very quickly, as soon as the chemical is no longer being produced, the oxygen molecules are again trapped by the mitochondria and are not available for the production of light.
Fireflies appear to light up for a variety of reasons. The larvae produce short glows and are primarily active at night, even though many species are subterranean or semi-aquatic. Fireflies produce defensive steroids in their bodies that make them unpalatable to predators. Larvae use their glows as warning displays to communicate their distastefulness. As adults, many fireflies have flash patterns unique to their species and use them to identify other members of their species as well as to discriminate between members of the opposite s e x. Several studies have shown that female fireflies choose mates depending upon specific male flash pattern characteristics. Higher male flash rates, as well as increased flash intensity, have been shown to be more attractive to females in two different firefly species.
Answer:
Cushing's syndrome
Explanation:
Prolonged hypersecretion of glucocorticoid hormones by the adrenal gland causes a hormonal imbalance where the person begins to accumulate fat and lose bone and muscle mass.
Remember, one of the most important glucocorticoid hormone is cortisol, also known as the stress hormone, it usually helps us respond to conditions that are difficult for our body and where we need to use our strength and mental dexterity, when this hormone is elevate, we can respond to stress situations more easily. It helps us activate all the metabolism, as a result, we need to use more energy.
If cortisol remains elevated all day, despite not making physical and mental strength, our body will think it needs to eat, so people with this syndrome are always hungry, and accumulate fat. Thus leading to the appearance of the symptoms of the syndrome.
Answer:
Physical Change:
- Boiling water
- Breaking a pencil
- Water evaporating
- Denting a car door in an accident
- Tearing paper
- Ice melting
- dissolving
Chemical Change:
- Something rusting
- photosynthesis
- metabolism/digestion
- Nuclear power [atoms are arranged differently]
- Smashing paper with two metal balls, burns paper
- Electricity in water, breaks H2O into H2 and O2
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physical change is when there is only physical change occurring--and it can typically be undone easily,
whereas chemical change is when there is chemical change--which changes the chemical properties of something, which cannot be undone simply.
hope this helps!!
