1. Explain how fossils are formed and give three examples.

2. Compare relative and radioactive dating.

3. Describe how Miller and Urey tested Oparin's hypothesis and the results of the

experiment.

4. Explain the endosymbiotic theory proposed by Lynn Margulis and two pieces of

evidence for the theory.

1)Practically all living creatures can leave fossils, yet generally just the hard pieces of plants and creatures fossilize. Delicate inner organs, muscle, and skin quickly rot,but the bones and shells of creatures are acceptable possibility for fossilization. Fossils are formed in various manners, however most are firmed when a plant or creature dies in a watery domain and is covered in mud and sediment. Delicate tissues rapidly disintegrate leaving the hard bones or shells behind. After some time sediments forms over the top and solidifies into rock. As the encased bones rot, minerals leak in supplanting the natural material cell by cell in a procedure called "petrification." Alternatively the bones may totally rot leaving a cast of the creature. The void may then load up with minerals making a stone imitation of the organism. Examples includes bones, shells, exoskeleton.

2)Radioactive dating empowers geologists to record the historical backdrop of the earth and its occasions, for example, the dinosaur time, inside what they call the geologic time scale.

Radioactive dating utilizes the proportions of isotopes and their particular decay products to decide the ages of rocks, fossils, and different substances. Whereas, Relative dating is utilized to organize topographical occasions, and the rock they abandon, in an arrangement. The strategy for perusing the request is called stratigraphy (layers of rock are called strata). Relative dating doesn't provide actual numerical dates.

Relative dating determines the squence of past events.

Radioactive dating determines actual ages of past events.

4)In 1953, two scientists, Harold Urey and his student Stanley Miller, set out to test Oparin and Haldane's hypothesis. They attempted to compute the substance constituents of the environment of the early Earth. They put together their estimations with respect to the view that the early atmosphere was diminishing.

Miller passed a constant electrical discharge mimicking lightning through a mixture of gases(such as methane, ammonia, hydrogen sulphide) that were thought to make up the early atmosphere. Toward the end of one week, as much as 10-15 % of the carbon was in the form of organic compounds. The experiment was an achievement as amino acids, were produced during the simulation.

4)Lynn Marguilis endosymbiotic theory suggest that eukaryotic cells evolved from prokaryotic organism such as bacteria. She concluded that both chloroplasts and mitochondria evolved from once free living bacteria. The evidence that proved this theory:

1)Both purple aerobic bacteria and mitichondria synthesize ATP using oxygen via kreb cycle and oxidative phosphorylation. Moreover, Chloroplasts and photosynthetic bacteria have similar chlorophyll that uses light energy and convert it into chemical energy.

2)Mitochondria have their own circular DNA which is similar to bacterial DNA

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rising temperatures because when water vapor in the air is cooled, it condenses. it turns back into a liquid and attaches to dust particles in the air. these very small water droplets group together to form clouds