Answer:
Advanced forms of life existed on earth at least 3.55 billion years ago. In rocks of that age, fossilized imprints have been found of bacteria that look uncannily like cyanobacteria, the most highly evolved photosynthetic organisms present in the world today. Carbon deposits enriched in the lighter carbon-12 isotope over the heavier carbon-13 isotope-a sign of biological carbon assimilation-attest to an even older age. On the other hand, it is believed that our young planet, still in the throes of volcanic eruptions and battered by falling comets and asteroids, remained inhospitable to life for about half a billion years after its birth, together with the rest of the solar system, some 4.55 billion years ago. This leaves a window of perhaps 200-300 million years for the appearance of life on earth.
divine interventionThis duration was once considered too short for the emergence of something as complex as a living cell. Hence suggestions were made that germs of life may have come to earth from outer space with cometary dust or even, as proposed by Francis Crick of DNA double-helix fame, on a spaceship sent out by some distant civilization. No evidence in support of these proposals has yet been obtained. Meanwhile the reason for making them has largely disappeared. It is now generally agreed that if life arose spontaneously by natural processes-a necessary assumption if we wish to remain within the realm of science-it must have arisen fairly quickly, more in a matter of millennia or centuries, perhaps even less, than in millions of years. Even if life came from elsewhere, we would still have to account for its first development. Thus we might as well assume that life started on earth.
How this momentous event happened is still highly conjectural, though no longer purely speculative. The clues come from the earth, from outer space, from laboratory experiments, and, especially, from life itself. The history of life on earth is written in the cells and molecules of existing organisms. Thanks to the advances of cell biology, biochemistry and molecular biology, scientists are becoming increasingly adept at reading the text.
An important rule in this exercise is to reconstruct the earliest events in life's history without assuming they proceeded with the benefit of foresight. Every step must be accounted for in terms of antecedent and concomitant events. Each must stand on its own and cannot be viewed as a preparation for things to come. Any hint of teleology must be avoided.
Answer:
an investigation on how copper affects aquatic life in the reservoir
Explanation:
It was observed that there were two time periods represented in the sediment by larger levels of copper than is recommended in sediment quality guidelines at the San Carlos Reservoir in Arizona
The next things that will be on their mind is to investigate on how copper affects aquatic life in the reservoir
Answer:
connective tissue comes in a vast variety of forms, yet they typically have in common 3 characteristic components: cells, large amounts of amorphous ground substance, and protein fibers
Mitochondrial DNA (mtDNA) typing is used in forensic science for it serves as an important tool in determining the recovered damaged, degraded or small sample source of the DNA. Mitochondrial DNA is a small genome that is found in the mitochondria, just outside of the nucleus of the cell.
Answer:
1.transports oxygen, nutrients , hormones to the cells and removes metabolic waste
2. breaks down food into nutrients
3. to protect the body from microbes and chemicals
4. responsible for the control and communication between body parts.
5. responsible for taking in oxygen and expelling CO2
6. produces, stores and eliminates urine the fluid waste the kidneys filter from the blood.
7. (#1High blood pressure)(vagus nerve damage slows digestion)(hbp weakens immune system)(nerve damage from high glucose levels)(lung function decrease as glucose levels rise)(promote bacteria growth causing uti)
8..........okay I got too lazy to do the rest....just search em up on Google.
