history of life worksheet – Flashcards

Earth has formed 4.6 billion years ago

Geological events on Earth set up conditions that would play a major role in the evolution of life on Earth

By the end of the Mesozoic, the continents took on their modern shape

The first organisms appeared on land between 3.9 and 3.4 billion years ago

Trace Fossil

Amber-Preserved

Petrified Fossil

Fossil

Imprint

Mold

Cast

Relative Dating

What is the limitation of relative dating

How do paleontologist determine the specific age of a fossil

How do scientist use radiometric dating to determine the age of rocks or fossils

The first photosynthetic bacteria form dome-shaped structures called stromatolites

Primates evolve and diversify

Divided into three periods: Triassic, Jurassic, and Cretaceous

An explosion of life, characterized by the appearance of many types of invertebrates and plant phyla

Mammals appear

Dinosaurs roam earth, and the ancestors of modern birds evolve

Flowering plants appear

Amphibians and reptiles appear

Early scientists believed that life arose from (1)____ through a process they called (2)___

In 1668, the Italian physician (3)___ conducted an experiment with flies that (4) _____ spontaneous generation

Biologist began to use an important new research tool the (5)___. They soon discovered the vast world of (6) ___. The number and diversity of these organisms was so great the the scientist were led to believe once again that these organisms must have arisen (7)___

By the mid 1800's, however (8)____ was able to disproved spontaneous generation once and for all. He set up an experiment, using flasks with unique (9)___ necks. These flasks allowed (10)___, but no organisms to come into contact with a broth containing nutrients. If some (11)___existed, as had been suggested, it would be able to get into the (12)___through the open neck of the flask. His experiment proved that organisms arise only from other (13)___. This idea is called (14)___ is one of the cornerstone of biology today

Biogensis (explains)

For life to begin, simple (inorganic) molecules had to be formed an then organized into complex molecules

several billion years ago, earths atmosphere had no free (methane)

Primitive earths atmosphere may have been composed of water vapor, carbon dioxide and (nitrogen)

in the early 1900s, Alexander Oparin proposed a widely accepted hypothesis that life began on (land)

(Pasture) hypothesized that many chemical reactions occurring in the atmosphere resulted in the formation of primordial soup

in 1953 Miller and Urey tested Oparins hypothesis by simulated the conditions of (modern) earth in the laboratory

Miller and Urey showed that organic compounds, including (nucleic acids) and sugars, could be formed in the laboratory just as predicted

This life in a test tube experiment of Millers and Urey provides support for some modern hypothesis of (biogensis)

Sidney Fox took Miler and Ureys experiment further and showed how amino acids could cluster to form (protocells)

What was the characteristics of the first organisms on earth

What is an autotroph? What factors helped them thrived on earth

What present day organism may be similar to the first autotrphs? why?

what change in the earths atmosphere after the evolution of photosynthezing prokaryotes

Basic elements

1942 a Russian, _____ developed a theory to explain, in his view the origin of life on earth. in 1929 an English man____ developed basically the same idea of how life began on earth

OPARINS THEORY -compounds in the air are ____ methane, H2, ____+____;new substances in the form of ions;ions recombine to form new organic complex molecules;_____; organic soup pools are formed on earths surface;____increased molecules reactions;more complex molecules are formed which became the first living cells, prokaryotes. Think were similar to present day ____; 1953 STANLEY MILLER EXPERIMENT -Miller tested Oparins theory in lab, reproduced Oparins ideas, found organic soup, had two know amino acids, alanine and glycine;_____;molecules similar to DNA is formed;____;_____; NOW COMBINED -First cells were similar to bacteria, cells were ____ and___; reproduced, have plenty of food and space in the organic soup pools on earths surface;large numbers of cells are now present. Therefore, there is a lot of competition for food. This may have lead to adaptation, maybe even ____;_____appeared and carried on process of chemsynthesis. some cells eventually carrying on photosynthesis, which insures better survival and increase in reproduction due to presence of O2 and usage of CO2 these photosynthetic cells were probably like our blue green algae___; Now there is a balance of heterotrophic cells and autotrophic cells these environments, pools of water on the surface of the earth is in a homeostatic situation;both kinds of cells mingle and form colonies the cells in the colonies help to support each other by providing food and O2;____cells were formed_____developed from aerobic bacteria which appeared after O2 was released into the atmosphere chloroplast developed from blue green algae

1992 Sidney Fox heated solutions of amino acids, made protocells-can divide and grow

____develop from prokaryotic cells

1960 Lynn Margul's, prokaryotic cells ingested aerobic bacteria>mitochondria Prokaryotic cells ingested bacteria having chlorophyll>chloroplast Mitochondria and chloroplast have own DNA and can divide