Asking a Question For years….. ____________________! Maggots on meat Mold on bread Fruit Flies on bananas How do new living things come into being?

Forming a Hypothesis ______________________– life could arise from non-living matter. Beetles from dung Mice from grain All created by _________________________

Forming a Hypothesis Spontaneous Generation is a hypothesis! 1668 Francesco Redi Italian physician Proposed a hypothesis for appearance of maggots Observed organisms (maggots) appeared on meat a few days after flies. Thought….. “_______________?”

Forming a Hypothesis Proposed a new _________________: Next step: Flies produce maggots, not meat Next step: TEST _____________________!

Setting up a Controlled Experiment The factors in an experiment that can change are the ______________________. ________________________________________ __________________________________________. Whenever possible, a hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged, or _____________. _____________________________________

Setting up a Controlled Experiment Variable that is deliberately changed = _____________________(manipulated variable) Variable that is observed and that changes in response to the manipulated variable is called the = __________________(responding variable) MILK LAB What is the independent variable? ________________________________ What was dependent variable? __________________________

Setting up a Controlled Experiment Testing for maggots How would you use meat to see if maggots are spontaneously generated from meat? ______________________________________ Work with your lab partner to create an experiment. ____________________________________

Setting up a Controlled Experiment What are you going to control (___________variables)? ___________________

Setting up a Controlled Experiment What is your independent variable (manipulated variable)? ___________________________ PAGE 9 EXPERIMENT

Recording and Analyzing Results Archimedes 287 BC to 211 BC Notebooks Journals Leonardo da Vinci 1452 to 1519 Archimedes - physics are the foundations of hydrostatics, statics and an explanation of the principle of the lever.

Galileo Galilei    1564-1642 Historical Use As long as people have been investigating natural phenomena, they have been keeping records of what they do. Why? It would appear that keeping records allows the investigator to go back and review original thoughts or to modify their thoughts. The science notebook is an integral part of the investigative process.

Drawing a Conclusion Use data from an experiment to evaluate the hypothesis and draw a valid _____________. Use evidence to determine if hypothesis was _____________or ___________________. Redi’s results supported or refuted his hypothesis? _______________________ HUGE ISSUE! _______________________________________!

1862 Pasteur & Spontaneous Generation Curved neck flask & broth Air was ___________to the source of life Redi’s experiment did not allow air in Pasteur believed __________________ were responsible for growth -Curved flask let air in, but micro- organisms could not enter. *________________________! Broke neck = full of microorganisms! *FINALLY DISPROVED _________________________ ______________________________!

How a Theory Develops As evidence from numerous investigations builds up, a particular _______________may become so well supported, scientists consider it a theory. In science, the word ___________applies to a well tested explanation that unifies a broad range of explanations.

Studying Life – 1.3 Objectives Describe some characteristics of living things Explain how life can be studied at different levels

Studying Life The word biology means the study of life http://www.youtube.com/watch?v=vX07j9SDFcc _______________is the science that seeks to understand the living world A biologist is someone who uses ______________ methods to study living things

8 Characteristics of Living Things Living things share these characteristics: _______________________ Reproduce Based on a genetic code ______________________ Obtain and use materials & energy Respond to their ________________ Maintain a stable internal environment _______________________________

Made Up of Cells Living things are made up of small, self-contained units called, __________. _____________– collection of living _________ enclosed by a barrier that separates the cell from its surroundings. ______________are the __________units of an organism considered to be alive. Very complex and highly ____________!

Made Up of Cells _____________organisms – single celled _______________– many celled Human body has at least 85 different types of cells!

Reproduction All organisms produce new organisms through a process called ______________. ______________Reproduction– the cells from two different parents ________to produce the first cell of the new organism. Maple trees Birds Humans

Reproduction 2. _______________Reproduction – new organism has a single parent. ______-_________organism divides in half to form two new organisms.

Based on a Genetic Code Offspring usually resemble their parents ______________Reproduction – offspring __________from their parents

Based on a Genetic Code _______Reproduction – offspring and parents have the _________traits

Based on a Genetic Code Directions for inherit traits is one of the greatest achievements of modern biology. ________ Deoxyribonucleic acid Determines directions for _____________

Growth and Development All living things grow and develop From ________fertilized egg cell  ____ death Need for materials and energy __________________ The combination of chemical reactions through which an organism builds up or breaks down materials as it carries out life processes.

Response to the Environment A stimulus is a signal to which an organism responds. If you are hungry, your stomach growls Plant roots grown in the direction of gravity _________of light & temperature are examples of factors that alter living things _______________.

Maintaining an Internal Balance _______________– involves internal feedback mechanisms Hot = sweat to cool you off Increased heart rate, increase need for oxygen, increase breathing rate

Figure 1-21 PAGE 21

Tools & Procedures 1.4 Objectives Describe the measurement system most scientists use Explain how light microscopes and electron microscopes are similar and different Describe two common laboratory techniques Explain why it is important to work safely in biology

A Common Measurement System Most scientists use the metric system when collecting data and performing experiments. SI system; International System of Units FIGURE 1-23 page 24

At what time of day is the rate of water released by leaves equal to the rate of water absorbed by roots? FIGURE 1-24 page 25

Microscopes Microscopes that produce magnified images of structures that are too small to see with the unaided eye. ______________microscopes – magnify images by focusing visible light rays. ______________microscopes – magnify by focusing beams of electrons.

______Microscope Compound light microscopes allow light to pass through the specimen and uses 2 lenses to form an image. ___________________

_________________Microscope More detailed than _______microscopes Transmission Electron Microscopes (TEM’s) Shine beam of electrons through a thin specimen Scanning Electron Microscopes (SEM’s) _____________________ All specimens are dead

Page 27 Analyzing Data Work with your partner to complete the 5 questions. Turn them in with your name, date, and class period on all papers.