WEEK-1-Q.-2-EARTH-AND-LIFE sample ex.pptx

Earth scie

1. INTRODUCTION TO LIFE SCIENCE

2. PERFORMACE TASK!

3. BIOLOGY is a science that deals with all forms of life, including their classification, physiology, chemistry, and interactions. The term was introduced in Germany in 1800 and popularized by the French naturalist Jean-Baptiste de Lamarck as a means of encompassing the growing number of disciplines involved with the study of living forms.

4. Where did life begin?

5. THEORY OF SPECIAL CREATION

6. COSMOZOIC THEORY(PANSPERMIA THEORY the idea proposed by Richter in 1865 and supported by Arrhenius (1908). According to this theory, life has reached the planet Earth from other heavenly bodies such as meteorites, in the form of highly resistant spores of some microorganisms.

7. The spores of some microorganisms are called cosmozoa or panspermia because they are preserved inside meteorites coming to the earth from the outer space. These meteorites struck the barren earth to release the cosmozoa and they developed into different creatures on the earth.

8. Panspermia Theory Greek word literally means seed everywhere. States that the seeds of life exist all over the universe and can be propagated through space from one location to another.

9. Theory of Spontaneous Generation also known as Abiogenesis, the idea that life arose from nonlife more than 3.5 billion years ago on Earth. Abiogenesis proposes that the first life-forms generated were very simple and through a gradual process became increasingly complex.

10. Spontaneous generation

11. Biogenesis Theory life is derived from the reproduction of other life, was presumably preceded by abiogenesis, which became impossible once Earth’s atmosphere assumed its present composition.

12. Biogenesis theory Postulates the production of new living organisms from pre-existing life. LOUIS PASTEUR proved that microbes come from other microbes.

13. Primordial Soup Theory According to primordial soup theory proposed by Alexander Oparin and John Haldane , life started in a primordial soup of organic molecules. Some form of energy from lightning combined with the chemicals in the atmosphere to make the building blocks of protein known as the amino acids.

14. Alexander Ivanovich Oparin A Soviet biochemist was notable for his theories about the origin of life and also for his book The Origin of Life. He also studied the biochemistry of material processing by plants and enzyme reactions in plant cell.

15. John Scott Haldane a physiologist is famous for intrepid self experimentation which led to many important discoveries about human body and the nature of gases. Later, they both came up with the Oparin-Haldane hypothesis which suggested that if the primitive atmosphere was reducing (as opposed to oxygen-rich), and if there was an appropriate supply of energy, such as lightning or ultraviolet light, then a wide range of organic compounds might be synthesized .

16. COACERVATE THEORY it is expressed by the Russian biochemist A.I. Oparin in 1936 suggesting that the origin of life was preceded by the formation of mixed colloidal units called coacervates. These are particles composed of two or more colloids which might be protein, lipid or nucleic acid. He proposed that while these molecules were not living, they behaved like biological systems in the ancient seas. They were subject to natural selection in terms of constant size and chemical properties, there was a selective accumulation of material and they reproduced by fragmentation.

17. COACERVATE Are formed when several combinations of proteins and carbohydrates are added to water.

18. Miller-Urey hypothesis . The first hypothesis where lightning could have operated the synthesisreactions in the Earth’s early atmosphere was tested by in 1953. It provided the first evidence thatorganic molecules needed for life could be formed from inorganic components. Some scientistssupport the RNA world hypothesis, which suggests that the first life was self-replicating RNA.

19. Fossil Evidence

20. Early forms of life The first forms of life are believed to have appeared some 3.5 billion years ago. Photosynthetic organisms are organisms who make their own food by utilizing the energyfrom the sun and the carbon dioxide in the atmosphere. The process of photosynthes is produced more oxygen that changed the Earth’s early atmosphere, allowed oxygen-breathing organisms to exist. Cyanobacteria (blue-green algae) are the first photosynthetic organisms to form

21. MICROFOSSILS are fossils that contain the remains of tiny plants and animals. They are very small and can be measured in millimeters, and some could only be identified under a microscope. Some of the remains of organisms do not have a nucleus so they were called prokaryotes. They are known to be the earliest forms of life.

22. ACTIVITY TIME!