Section 1-1: The World of Biology
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Section 1-1: The World of Biology Section 1-2: Themes in Biology Section 1-3: The Study of Biology Section 1-4: Tools + Techniques. CHAPTER 1 – THE SCIENCE OF LIFE. Biology + You Biology The study of life

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CHAPTER 1 – THE SCIENCE OF LIFE

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Chapter 1 the science of life

Section 1-1: The World of Biology

Section 1-2: Themes in Biology

Section 1-3: The Study of Biology

Section 1-4: Tools + Techniques

CHAPTER 1 – THE SCIENCE OF LIFE


Section 1 1 the world of biology

  • Biology + You

    • Biology

      • The study of life

    • Offers an organized and scientific framework for posing + answering questions about the natural world

Section 1-1: the world of biology


Section 1 1 the world of biology1

  • Biologists study questions about:

    • How living things work

    • How they interact with their environment

    • How they change over time

  • Studies many different kinds of living things

    • Examples: bacteria to elephants

Section 1-1: the world of biology


Section 1 1 the world of biology2

  • By studying biology you can make important decisions on issues that impact you and society

  • Biologists actively work to solve real-world issues + problems

    • Examples:

      • Improving foodsupply

      • Curing diseases

      • Preserving our environment

Section 1-1: the world of biology


Section 1 1 the world of biology3

  • Characteristics of Life

    • Living things share 7 characteristics of life

Section 1-1: the world of biology


Section 1 1 the world of biology4

  • (1) Organization + Cells

    • Organization

      • The high degree of order within an organism’s internal + external parts and in its interactions with the living world

      • Ex: Rock vs. Owl?

    • All living things, whether made up of 1 cell or many cells have some degree of organization

Section 1-1: the world of biology


Section 1 1 the world of biology5

  • Organization + Cells

    • Cell

      • The smallest unit that can perform all life’s processes

        • Unicellular

          • Organisms made up of only 1 cell

          • Ex: bacteria

        • Multicellular

          • Organisms made up of multiple cells

          • Ex: humans or trees

Section 1-1: the world of biology


Section 1 1 the world of biology6

  • Organization + Cells

    • Reverse Biological Hierarchy

      • Organ systems

        • Group of organs

      • Organs

        • Group of tissues

      • Tissues

        • Group of cells

      • Cells

      • Organelles

        • Tiny cell structures that carry out functions necessary for the cell to stay alive

      • Biological molecules

        • Chemical compounds used in structures + other cellular functions

      • Atoms

        • Simplest particle of an element that retains all the properties of a certain element

Section 1-1: the world of biology


Section 1 1 the world of biology7

  • (2) Response to Stimuli

    • Stimulus

      • A physical or chemical change in the internal or external environment

      • Example:

        • Brightness of light

      • Organisms must be able to respond + react to changes in the environment to stay alive

Section 1-1: the world of biology


Section 1 1 the world of biology8

  • (3) Homeostasis

    • A mechanism to maintain stableconditions

    • Example:

      • Water content in a cell

    • Homeostasis

      • The maintenance of a stable level of internal conditions even though the environmental conditions are constantly changing

    • Organisms have regulatory systems that maintain internal conditions such as:

      • Temperature

      • Water content

      • Uptake of nutrients by the cell

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Section 1 1 the world of biology9

  • (4) Metabolism

    • Living organisms use ENERGY to power all the processes such as repair, movement, + growth

    • Metabolism

      • Sum of all the chemical reactions that take in and transform energy and materials from the environment

      • Example:

        • PHOTOSYNTHESIS (plants)

        • Obtaining FOODENERGY (animals)

Section 1-1: the world of biology


Section 1 1 the world of biology10

  • (5) Growth + Development

    • All living things grow and increase in size

    • Nonliving things, such as crystals or icicles, grow by accumulating more of the same material they are made of

    • Growth of living things result from division + enlargement of cells

Section 1-1: the world of biology


Section 1 1 the world of biology11

  • Growth + Development

    • Cell Division

      • The formation of 2 new cells from an existing cell

        • Unicellular

          • Division, enlargement

        • Multicellular

          • Division, enlargement, development

    • Development

      • The process by which an organism becomes a mature adult

        • Involves cell division + cell differentiation (specialization)

        • As a result of development, an adult organism is composed of many cells specialized for different functions

Section 1-1: the world of biology


Section 1 1 the world of biology12

  • (6) Reproduction

    • Reproduction

      • Process of producing new organisms

        • Not essential to the survival of an individualorganism

        • Essential for the continuation of a species

        • During reproduction, organisms transmit hereditary information to their offspring

          • Known as deoxyribonucleicacid (DNA)

            • Gene

              • Short segment of DNA that contains the instructions for a single trait

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Section 1 1 the world of biology13

  • Reproduction

    • Sexual

      • Hereditary info. combines from two parents

        • sperm + egg

      • Offspring similar to parents, not identical

      • Example: Frogs

    • Asexual

      • Hereditary info. Not combined; only one parent reproduces

      • Offspring identical to parent

      • Example: Bacteria

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Section 1 1 the world of biology14

  • (7) Change through Time

    • Although individual organisms experience many changes during their lifetime, their basic genetic characteristics do not change

    • However, populations of living organisms evolve or change through time

    • The ability of populations of organisms to change over time is important for survival in a changing world

    • This also explains the diversity of life-forms

Section 1-1: the world of biology


Section 1 1 what to know

All definitions

Meaning of Biology (purpose, how it affects your lives, etc…)

7 Characteristics of Life (meanings + examples)

Section 1-1: WHAT TO KNOW…


Section 1 2 themes in biology

  • (1) Diversity + Unity of Life

    • Diversity

      • Variety of life

    • Biologists have identified more than 1.5 million species on Earth

Section 1-2: themes in biology


Section 1 2 themes in biology1

  • Unity

    • Features that all living things have in common:

      • The genetic code

        • Rules that govern how cells used the hereditary information in DNA

      • Presence of organelles that carry out all cellular activities

Section 1-2: themes in biology


Section 1 2 themes in biology2

  • “Tree of Life Model”

  • Places organisms that have more similar sets of genes on closer branches, or lineages, of the tree

  • They place more distantly related organisms on more distant branches

  • Scientists think that all living things have descended with modification from a single common ancestor

    • Thus all of life is connected

  • How do Biologists group life?

Section 1-2: themes in biology


Tree of life model

“Tree of life” model


Section 1 2 themes in biology3

Section 1-2: themes in biology

  • Domains

    • 3 major subdivisions

      • Bacteria

      • Archaea

      • Eukarya

  • Kingdoms

    • 6 major categories

      • Eubacteria

      • Archaebacteria

      • Fungi

      • Protista

      • Plantae

      • Animalia


Section 1 2 themes in biology4

  • (2) Interdependence of Organisms

    • Ecology

      • Branch of biology that studies organisms interacting with each other and the environment

      • Studies show that organisms depend on each other as well as on minerals, nutrients, water, gases, heat, etc…

Section 1-2: themes in biology


Section 1 2 themes in biology5

  • (3) Evolution of Life

    • Individual organisms change during their lifetime, but their genetic characteristics do not change

    • Evolution

      • Process by which the inherited characteristics within populations change over generations

        • “Descent with modification”

Section 1-2: themes in biology


Section 1 2 themes in biology6

  • Evolution of Life

    • As a theme it helps us understand how the various branches of the “treeoflife” came into existence and have changed over time

    • It also explains how organisms alive today are related to those that lived in the past

    • It also helps us understand the mechanisms that underlie the way organisms look and behave

Section 1-2: themes in biology


Section 1 2 themes in biology7

  • NaturalSelection

    • Theory of Natural Selection

      • Organisms that have certain favorable traits are better able to survive and reproduce successfully than organisms that lack these traits

    • Adaptations

      • Traits that improve an individuals ability to survive and reproduce

        • Ex. Rabbits + their envt

    • The survival and reproductive success of organisms with favorable traits cause a change in populations of organisms over generations

    • This descent with modification is an important factor in explaining the diversity of organisms we see on Earth today

Section 1-2: themes in biology


Section 1 2 what to know

All definitions

Themes of Biology (be able to explain each)

Examples for topics

Section 1-2: what to know…


Section 1 3 the study of biology

Science is a systematic method that involves forming and testing hypotheses

Science relies on evidence, not beliefs, for drawing conclusions

Section 1-3: the study of biology


Section 1 3 the study of biology1

  • Science as a process

    • Science is categorized by an organized approach called the scientificmethod

      • Based on two important principles:

        • Events in the natural world have natural causes

          • Example: Thundering + Lightning

        • Uniformity

          • The idea that the fundamental laws of nature operate in the same way at all places and at all times

            • Example: the law of gravity

Section 1-3: the study of biology


Section 1 3 the study of biology2

Steps to the scientific method:

Section 1-3: the study of biology


Section 1 3 the study of biology3

  • (1) Observation:

    • The act of perceiving a natural occurrence that causes someone to pose a question

  • (2) Form a hypothesis:

    • A proposed explanation for the way a particular aspect of the natural world functions

  • (3) Make a prediction:

    • A statement that forecasts what would happen in a test situation if the hypothesis were true

Section 1-3: the study of biology


Section 1 3 the study of biology4

  • (4) Experiment:

    • Used to test the hypothesis + predictions

    • Controlledexperiment

      • Compares an experimental group + a control group

        • Control group– normal standard

        • Experimental group – has one difference from control group

          • Independent variable – manipulated variable

          • Dependent variable – responding variable (affected by IV)

Section 1-3: the study of biology


Section 1 3 the study of biology5

  • (5) Collecting data, analyzing data, + drawing conclusions

    • Quantitative data

      • Data measured in numbers

    • The goal of analyzing data is to determine whether the data are reliable, and whether they support or fail to support the predictions or hypothesis

      • May use statistics to determine relationships between variables

    • An experiment can only disprove, not prove, a hypothesis

Section 1-3: the study of biology


Section 1 3 the study of biology6

  • Inference

    • A conclusion made on the basis of facts and previous knowledge rather than on direct observation

      • Ex. If you see smoke….

    • Build models to represent or describe things

  • Theory

    • When a set of related hypotheses are confirmed to be true many times, and it can explain a great amount of data

      • Examples:

        • Cell Theory

        • Theory of Evolution

Section 1-3: the study of biology


Section 1 3 the study of biology7

  • (6) Communicate data

    • Collaboration with other scientists is important to public knowledge

      • Publish findings in scientific journals

      • Present them at scientific meetings

Section 1-3: the study of biology


Section 1 3 what to know

All definitions

Steps of Scientific Method (be able to explain each)

Examples for topics

Section 1-3: what to know…


Section 1 4 tools techniques

  • Microscopes as Tools

    • Tools

      • Objects used to improve the performance of a task

    • Microscopes

      • Tools that extend human vision by making enlarged images of objects

        • Used to study organisms, cells, cell parts, and molecules

Section 1-4: Tools + Techniques


Section 1 4 tools techniques1

  • Light Microscope (compound)

    • Shines light through a specimen and has two lenses to magnify an image

Section 1-4: Tools + Techniques


Section 1 4 tools techniques2

  • 4 major parts of CLM:

    • Eyepiece

      • AKA - ocular lens

      • Magnifies image 10x

    • Objective Lens

      • Enlarges image of the specimen

      • Found on revolving nosepiece

      • May have up to 4 different powered lenses

    • Stage

      • Platform that supports a slide holding the specimen

    • Light Source

      • Provides light for viewing the image

      • Lamp or mirror

Section 1-4: Tools + Techniques


Section 1 4 tools techniques3

  • Magnification + Resolution

    • Magnification

      • The increase of an object’s apparent size

      • PowerofMagnification

        • Degree of enlargement

          • Ocular lens x Objective lens

            • Example: 10 x 25 = 250x

      • *CLM – highest mag = 2,000x

    • Resolution

      • The power to show details clearly in an image

Section 1-4: Tools + Techniques


Section 1 4 tools techniques4

  • Electron microscopes

    • Uses a beam of electrons to produce an enlarged image of an object

      • Used to examine cells in more detail or to view cell parts or viruses

      • More powerful in magnification + resolution than LM

      • Images are always in black & white

      • Specimen is placed in a vacuum

      • Cannot view living specimens

Section 1-4: Tools + Techniques


Section 1 4 tools techniques5

Section 1-4: Tools + Techniques


Section 1 4 tools techniques6

Section 1-4: Tools + Techniques

  • SEM

    • Showers electrons over surface of specimen

    • Produces a 3-D image

    • 100,000x

  • TEM

    • Transmits electrons through specimen

    • Can see internal features of specimen

    • 200,000x


Section 1 4 tools techniques7

  • Units of Measure

    • Metric System

      • Common measurement system scientists use

      • Decimal system based on powers of 10

      • Known as the SI system

    • Base units

      • Fundamentals units used to describe measurements

      • Know prefixes – Table 1-2, p. 23

Section 1-4: Tools + Techniques


Section 1 4 tools techniques8

Section 1-4: Tools + Techniques


Section 1 4 tools techniques9

  • Derived units

    • Produced by mathematical relationships between two base units or derived units

    • Common examples:

      • Area (m2)

      • Volume (m3)

Section 1-4: Tools + Techniques


Section 1 4 tools techniques10

  • Safety

    • Hazards can be chemical, physical, radiological, or biological

    • “Common- sense” habits

      • Example:

        • Splashing chemicals into eyes

    • Know safety symbols – p. 24

Section 1-4: Tools + Techniques


Section 1 4 what to know

  • All definitions

  • Parts of Microscope (+ functions)

  • Differences between CLM + EM

  • SI System

    • Base units (know TABLE)

  • Safety Symbols

Section 1-4: what to know…


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