The Science of Biology

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Chapter 1

• The Science of Biology

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What is Science?

• The goal of science is to investigate and
  understand the natural world, to explain events
  in the natural world, and to use those
  explanations to make useful predictions.
• Science is an organized way of using evidence
  to learn about the natural world.

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• Thinking like a Scientist
• Observation the process of gathering
  information about events or processes in a
  careful orderly way.
• Data information gathered from observation
• Inference a logical interpretation based on
  prior knowledge or experience.

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Observation and Inference
Section 1-1
Statement Observation Inference
Object A is round and orange.
Object A is a basketball.

• Object A is a basketball.
• Object B is a table-tennis ball.
• Object C is a soccer ball.

Object C is round and black and white.
Object C is larger than Object B.
Object B is smooth.
Object B is a table-tennis ball.
Each object is used in a different sport.
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How Scientists Work

• Greek philosopher Aristotle about 2300 years ago
  made many observations and which went
  unquestioned for nearly 1900 years.
• One belief was that living things came from non
  living things.
• This was the idea of Spontaneous Generation.
• Beginning in the 1600s scientists began to
  question this hypothesis.

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• A hypothesis should be tested by an experiment if
  possible, a hypothesis should be tested by an
  experiment in which only one variable is tested
  at a time. All other variables should be kept
  unchanged, or controlled.
• This is a controlled experiment.

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• Manipulated variable the variable that is
  deliberately changed.
• Responding Variable the variable that changes
  in response to the manipulated variable.

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Flowchart
Section 1-2
Scientific Method
State the Problem
Analyze Results
Form a Hypothesis
Draw a Conclusion
Set Up a Controlled Experiment
Publish Results
Record Results
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Redis Experiment on Spontaneous Generation
OBSERVATIONS Flies land on meat that is left
uncovered. Later, maggots appear on the meat.
HYPOTHESIS Flies produce maggots.
PROCEDURE
Uncovered jars
Covered jars
Controlled Variables jars, type of
meat, location, temperature, time
Several days pass
Manipulated Variables gauze covering that keeps
flies away from meat
Responding Variable whether maggots appear
Maggots appear
No maggots appear
CONCLUSION Maggots form only when flies come in
contact with meat. Spontaneous generation of
maggots did not occur.
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Spallanzanis Experiment
Section 1-2
Gravy is boiled.
Flask is open.
Gravy is teeming with microorganisms.
Flask is sealed.
Gravy is free of microorganisms.
Gravy is boiled.
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Figure 1-11 Pasteurs Experiment
Section 1-2
Broth is boiled.
Broth is free of microorganisms for a year.
Curved neck is removed.
Broth is teeming with microorganisms.
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Studying Life

• Biology is the science that seeks to understand
  the living world.
• Biology comes from the Greek bios meaning life
  and logy means the study of.
• All living things share the following
  characteristics.

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Characteristics of Living Things

Characteristic
Examples
Living things are made up of units called cells.
Many microorganisms consist of only a single
cell. Animals and trees are multicellular.
Living things reproduce.
Maple trees reproduce sexually. A hydra can
reproduce asexually by budding.
Living things are based on a universal genetic
code.
Flies produce flies. Dogs produce dogs. Seeds
from maple trees produce maple trees.
Living things grow and develop.
Flies begin life as eggs, then become maggots,
and then become adult flies.
Living things obtain and use materials and energy.
Plants obtain their energy from sunlight.
Animals obtain their energy from the food they
eat.
Leaves and stems of plants grow toward light.
Living things respond to their environment.
Despite changes in the temperature of the
environment, a robin maintains a constant body
temperature.
Living things maintain a stable internal
environment.
Taken as a group, living things change over time.
Plants that live in the desert survive because
they have become adapted to the conditions of the
desert.
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• Cells is a collection of living matter enclosed
  by a barrier that separates the cell from its
  surrounding.
• Many living things consists of one cell and are
  called unicellular
• Most organisms are composed of more than one cell
  and are called multicellular

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• Reproduction The production of a new organism.
• Asexual reproduction the new organism comes
  from a single parent.
• Sexual reproduction The new organism has two
  different parents that unite to produce a new
  organism.

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• Metabolism The combination of chemical
  reactions through which an organism builds up or
  breaks down materials as it carries out life's
  processes.
• Stimulus a signal to which an organism
  responds.
• Homeostasis The process of keeping a constant
  internal environment.

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Section 1-3
The part of Earth that contains all ecosystems
Biosphere
Biosphere
Community and its nonliving surroundings
Ecosystem
Hawk, snake, bison, prairie dog, grass, stream,
rocks, air
Community
Populations that live together in a defined area
Hawk, snake, bison, prairie dog, grass
Group of organisms of one type that live in the
same area
Population
Bison herd
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Figure 1-21 Levels of Organization continued
Section 1-3
Organism
Individual living thing
Bison
Tissues, organs, and organ systems
Groups of Cells
Nervous system
Brain
Nervous tissue
Smallest functional unit of life
Cells
Nerve cell
Groups of atoms smallest unit of most
chemical compounds
Molecules
DNA
Water
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A Common Measurement System

• The Metric System

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History of the Metric System

• Weights and measures were among the earliest
  tools invented by man.
• Man first turned to parts of his body and his
  natural surroundings for measuring instruments.
• Length was first measured by the forearm, hand,
  finger, and that time was measured by the sun,
  moon and other heavenly bodies.

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• The invention of numbering systems and the
  science of mathematics made it possible to create
  whole systems of measurement units.
• Romans used the number 12 as a base number 12
  inches in a foot.
• King Henry I of Great Britain decreed that a yard
  was from the tip of his nose to the end of his
  outstretched thumb.

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• In the 1790 the National Assembly of France
  requested the French Academy of Sciences to
  deduce an invariable standard for all measures
  and weights.
• The length was to be a portion of the earths
  circumference.
• Volume was derived from the unit of length.
• Larger and small multiples of each unit were to
  be created by multiplying of dividing the basic
  unit of 10 and its powers.

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• The name metric comes from the Greek word
  metron, meaning a measure
• The physical standard representing the meter was
  to be constructed so that it would equal one
  ten-millionth of the distance from the North Pole
  to the Equator.
• This standard of measurement became lawful in the
  United States in 1866.

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• Mass is a measure of how much matter an object
  contains
• 1.Measuring Mass
• Compare the mass of the object with a standard
  amount or unit, of mass.

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• 2.Measuring Weight
• Weight is the downward pull of an object due to
  gravity
• The scientific unit for weight is Newton (N)

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• Volume is a Measure of the Space that Matter
  Occupies

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• A graduated cylinder contains 50 milliliters of
  water. Placing a rock in it causes the water
  level to rise to 55 milliliters. The difference
  of 5 mL therefore the volume of the rock is 5
  cm3

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• The volume of a liquid usually measured in liters
  (L) or milliliters (mL). One liter is equal to
  1000 milliliters. Milliliters and cubic
  centimeters are equivalent.

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Determining Volume by Formula

• A rectangular box, has a length, a width, and a
  height that can be measured.
• Volume L X W X H
• The volume has a unit of cubic centimeters (cm3)