Spontaneous Generation

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Spontaneous Generation. - PowerPoint PPT Presentation

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Spontaneous Generation From the time of the ancient Romans, through the Middle

Ages, and until the late nineteenth century, it was generally accepted that some life forms arose spontaneously from non-living matter. Such "spontaneous generation" appeared to occur primarily in decaying matter. For example, a seventeenth century recipe for the spontaneous production of mice required placing sweaty underwear and husks of wheat in an open-mouthed jar, then waiting for about 21 days, during which time it was alleged that the sweat from the underwear would penetrate the husks of wheat, changing them into mice. Although such a concept may seem laughable today, it is consistent with the other widely held cultural and religious beliefs of the time

Redi & Pasteur The studies of Redi and Pasteur

disproved the idea of Spontaneous Generation.

Robert Hooke Robert Hooke (1635-1703) Observed

cork through a microscope lens and noticed cells. He thought they served as containers for the fibrous threads once-living cork tree. He thought it only existed in plants.

Leeuwenhoek 1632-1723 Made some of first

microscopes Works included: 1674 Observed pond water and saw

alga and protozoa. He wrote extensive accounts of the

mouthparts and stings of bees.!

Schleiden Schleiden: 1804 - 1881studied mostly

plants , believed they all contained cells. He also recognized the importance of the cell nucleus, discovered in 1831 by the Scottish botanist Robert Brown, and sensed its connection with cell division. Schleiden was one of the first German biologists to accept Darwin’s theory of evolution. He became professor of botany

Schwann 1810-1882 He observed animal cells

and tissues and said all animals are made of cells. He showed that yeast were tiny plant-like organisms

Virchow 1821-1902 His work supported ideas of cell division and metabolism.

Cell Theory

Linnaeus Classification 18th Century, organisms are placed into

groups with similar structures and development.

Binomial Nomenclature Two part naming system. (Latin) Genus + Species Species = an organism that can mate

and produce fertile offspring.

Three Domain System Archaea Domain

•Archaebacteria Kingdom

Bacteria Domain

•Eubacteria Kingdom

Eukarya Domain

•Protista Kingdom

•Fungi Kingdom

•Plantae Kingdom

•Animalia Kingdom

Needs of Living Energy waterliving spacestable internal conditions** Oxygen : not all

Non – Living

Photosynthesis Producers use chlorophyll and other

pigments that capture light which powers the reaction. Extra starches are stored.

Cellular Respiration Carbohydrates are used for growth, maintenance, and

reproduction. Consumers, Chemical reactions occur that break

down food into simpler substances and release energy, enzymes are needed.

This process begins in the cytoplasm where CHO is broken down to glucose and other products, energy is released.

The products enter the mitochondria and more energy is released as well as CO₂ and H₂O.

Fermentation When cells don’t have enough O for

cellular respirations. Some store energy is released from stored energy.

Fermentation begins in the cytoplasm and energy is released but doesn’t move to the mitochondria. More reactions then occur in the cytoplasm which releases more energy and waste products of lactic acid or alcohol and CO₂.

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