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Updated July 5, 2004Created by C. Ippolito July 5, 2004 Studying Life What are some of the characteristics of living things? How can life be studied at.

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Presentation on theme: "Updated July 5, 2004Created by C. Ippolito July 5, 2004 Studying Life What are some of the characteristics of living things? How can life be studied at."— Presentation transcript:

1 Updated July 5, 2004Created by C. Ippolito July 5, 2004 Studying Life What are some of the characteristics of living things? How can life be studied at different levels? Chapter 1 Section 3 Pages

2 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Characteristics of Living Things Living things are made of cells 2. reproduce 3. are based on a universal genetic code 4. grow and develop 5. obtain and use materials and energy 6. respond to their environment 7. maintain a stable internal environment 8. taken as a group, change over time (evolve)

3 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Made of Cells Cells Cells – smallest unit of an organisms that possesses all characteristics of life Unicellular Unicellular composed of only one cell Multicellular Multicellular composed of many cells

4 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Reproduction Reproduction – process of making more of own kind Sexual Sexual – two special cells (gametes) two parent individuals new individual different from either parent individual Asexual Asexual – No special cells one parent individual new individual identical to parent individual

5 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Based on a Genetic Code Genetic Code – determines inherited traits DNA or RNA – DNA or RNA – carries inherited traits in all organisms on Earth Mechanisms of control are the same in all organisms on Earth

6 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Growth and Development All living things grow during their lifetime Unicellular Unicellular increase in size (growth) Multicellular Multicellular increase in size increase number of cells cells take on different roles (differentiation) may have different forms (development)

7 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Need for Materials and Energy Metabolism Metabolism – combination of chemical reactions needed to stay alive AnabolismSynthesis Anabolism (Synthesis) –build up materials. CatabolismDecomposition Catabolism (Decomposition) –break down materials to release energy to get substances needed to build up.

8 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Response to the Environment Stimulus Stimulus – a signal to which an organism responds, usually involves a change. External Stimuli External Stimuli – changes outside light temperature sounds. Internal Stimuli Internal Stimuli – changes inside pain chemical levels pressure.

9 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Maintaining Internal Balance Homeostasis Homeostasis – internal conditions remain constant when external conditions change. Thermostat – controls house temperature

10 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Evolution The very slow change of groups of organisms over time

11 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Branches of Biology Anatomy (anatomist) Biochemistry (biochemist) Botany (botanist) Cytology (cytologist) Ecology (ecologist) Genetics (geneticist) Paleontology (paleontologist) è Study of body structure è Study chemicals of life è Study of plants è Study of cells è Study of environment è Study of heredity è Study of ancient life

12 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Levels of Biological Organization Biosphere Ecosystem Community Population Organism System Organ Tissue Cell Organelle Molecule è Life found on Earth è All life and non living in area è All life in area è All life of one species in area è Individual life è Organs work together è Tissues work together è Cells work together è Structural & functional unit of life è Cell part with function è Chemical with function

13 Updated July 5, 2004Created by C. Ippolito July 5, 2004 Tools and Procedures What measurement system do most scientists use? How are light microscopes and electron microscopes similar? How are light microscopes and electron microscopes different? Chapter 1 Section 4 Pages

14 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Common Measurement System Metric System (SI System) Decimal system (based on multiples of 10) Units increase in 10’s to measure larger deka- deka- 10x hecto- hecto- 100x kilo- kilo- 1,000x mega- mega- 1,000,000x Units decrease in 10’s to measure smaller deci- deci- 1/10x centi- centi- 1/100x milli- milli- 1/1,000x micro- micro- 1/1,000,000x nano- nano- 1/1,000,000,000x

15 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Common Metric Units Length meter Volume liter Time second Mass gram Temperature degrees Celsius

16 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Microscope Light Microscope Light Microscope focus visible light Electron Microscope Electron Microscope focus beams of electrons produce magnified images of structures too small to see with unaided eye.

17 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Types of Electron Microscopes Transmission Transmission (TEM) beam through a thin sample of specimen show inside details Scanning Scanning (SEM) beam back and forth over the surface forms 3-D image

18 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 Lab Techniques Cell Cultures Cell Cultures grow groups of cells from a single cell cell responses cell interactions Cell Fractionation Cell Fractionation ultracentrifugation a.k.a ultracentrifugation separate cell parts function of organelle

19 Updated July 5, 2004 Created by C. Ippolito July 5, 2004 More Lab Techniques Chromatography Chromatography separates chemicals based on solubility Electrophoresis Electrophoresis separates chemicals based on charge/size DNA fingerprinting


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