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Introduction to Biology

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Presentation on theme: "Introduction to Biology"— Presentation transcript:

1 Introduction to Biology
Chapter One

2 What is Biology? Science- an organized way of gathering and analyzing evidence about the natural world Biology- the study of life

3 Themes of Biology Cell Structure and Function
Stability and homeostasis Reproduction and Inheritance Evolution Interdependence of organisms Matter, energy and organization *Can Sally Remember Every Idea Matters

4 Cell Structure and Function
Cell is the basic unit of life Two categories Unicellular- one cell Multicellular- many cells As cells develop they become different from each other (differentiation) Source One

5 Stability and Homeostasis
Homeostasis- maintaining stable level of internal conditions Example- body temperature Source two

6 Reproduction and Inheritance
Reproduction- process in which new organisms are produced DNA- form in which genetic information is passed to offspring Two Types of Repro Asexual- only one organism contributes Example- bacteria Sexual- two organisms contribute to offspring Example- humans, frogs

7 Evolution Evolution- study of the changes in organisms over time
Natural Selection- how evolution occurs Natural Selection acts upon characteristics that are favorable to environment leading to more reproduction

8 Interdependence of Organisms
Ecology- study of the interactions of organisms Ecosystem- environmental community Source three

9 Matter, Energy, Organization
Photosynthesis- process in which organisms capture energy from the sun Process that allows all life on Earth to exist Autotroph- organisms that make their own food from sun Example- plants Heterotroph- organisms that must consume others to meet energy needs Example- humans

10

11 Characteristics of Life
Reproduction All cells Respond to environment Energy (obtain and use) Homeostasis Organized with DNA Growth and development

12 Respond to Environment
Reproduction Sexual Asexual All Cells Unicellular Multicellular Respond to Environment Stimulus- signal to which an organisms responds Example- temperature, moisture, predators

13 Homeostasis- stable level of internal conditions
Energy- all organisms must take in materials and energy to grow, develop, reproduce Metabolism- sum of all the reactions occurring in the body Homeostasis- stable level of internal conditions DNA- universal genetic code, stores information needed to live, grow and reproduce

14 Growth and development
All organisms grow as a result of cell division and development Cell Division- forming new cells from existing cell Development- produced by repeated cell divisions and cell differentiation (cells becoming different from one another) Example- heart cells, bone cells, nerve cells

15 Scientific Method Ask Question Form hypothesis
Set up controlled experiment Record and analyze results Draw conclusion Publish

16 Ask Question- based on something you have seen or noticed (observation)
Form hypothesis- statement that explains the observation and can be tested (prediction or educated guess)

17 Setting up Controlled Experiment
Experiment is conducted by gathering data under controlled conditions Control group- group that contains all the norms Experimental group- group that has just one variable different from control Independent variable- one factor that is purposely changed in experiment Dependent variable-change that occurs in response to independent variable

18 Record/Analyze Results
Data-any and all information gathered to try and answer original question Quantitative- numbers, measurements Qualitative- descriptions of observations Recording- done in table or chart Analyzing- looks at data to determine trends and is reliable Type of analysis varies depending upon experiment

19 Draw Conclusion- looks at analysis to determine if hypothesis is supported or rejected
Publish- write a scientific paper or lab report to publish in journal

20 Microscopes Microscope- instrument that produces an enlarged image of an object Source Four

21 Magnification- is the increase of an objects apparent size
Must multiply eyepiece with objective lens to get total magnification Resolution- ability to show details clearly, higher resolution= better picture Good microscopes have both high magnification and high resolution

22 Types of Microscopes Light- uses a light source to shine through specimen Most common type used by biologists Electron- uses beams of electrons to produce enlarged image Produce high magnification, but can not be living Two types Transmission (TEM) Scanning (SEM)

23 Source Five

24 Measurements Metric System (SI)- system used around the world
Kept standard so no conversions are required We will always use Metric System in class Length- meter (m) Mass- gram (g) Time- seconds (s) Volume, liquids - liter (L) Temperature- Celsius (C )

25 Metric System All based upon the power of 10 Giga=1,000,000,000
Start at base unit, use prefixes to determine number Example 5 kilometers; kilo=1000 so 5 km= 5000 meters Giga=1,000,000,000 Mega= 1,000,000 Kilo= 1,000 Hecto= 100 Deka= 10 Deci= 1/10 Centi= 1/100 Milli= 1/1,000 Micro= 1/1,000,000

26 Level of Bodily Organization
Molecular- atoms together make organelles Organelles- different parts of the cell that have specific job making up the cell Cell- basic unit of life

27 Cont. Tissue- group of cells working together to perform a specific function Organ- two or more tissues working together to perform a specific function Organ System- two or more organs working together for a common purpose

28 Organism- all the organ systems working together
Heart cell, cardiac muscle tissue, heart, circulatory system, human

29 http://www. google. com/imgres. imgurl=http://www. sarahwray


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