Biology in the 21 st century
1 / 33

Biology in the 21 st Century - PowerPoint PPT Presentation

  • Uploaded on

Biology in the 21 st Century. Biological Questions. Gana. Gana. What is science?. Science is… The continual effort to discover and increase human understanding of how reality works .

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Biology in the 21 st Century' - malcolm-gamble

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

What is science
What is science?

  • Science is…

    • The continual effort to discover and increase human understanding of how reality works.

      • The systematic process allows us to better understand past events and predict future events of a similar kind.

        • Science is not static, it is ever changing.

What do you think
What do you think?

  • Define the following…

    • Fact

    • Hypothesis

    • Law

    • Theory

Biology in the 21 st century

  • A scientific fact is a controlled, repeatable and/or rigorously verified observation, probability of “truth” is incredibly high—little room for doubt.

    • An example of current facts:

      • All things with mass have gravity.

      • Gravity is an attractive force.

Biology in the 21 st century

  • Sometimes new discoveries make us have to re-evaluate and/or revise our “facts” – THAT’S SCIENCE!

  • Former Facts

    • There are three states of matter.

    • The Earth is flat.


  • A suggested explanation; a proposal based on reason that predicts a possible correlation between multiple phenomena (incidents, events, observations, etc.)

Biology in the 21 st century

  • Notes only that something happens, happens consistently and across the universe; usually simply stated; frequently can be stated mathematically.

  • Example:

    • Newtons 2nd Law: F = ma

      • A body of mass (m) subject to a force (F) undergoes an acceleration (a) that has the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass.


  • Notes why something happens, explains why laws and facts are true, a framework about a class or group of phenomena, sometimes valuable to predict.

    • Theories are never “proven”—they are confirmed by overwhelming data, all theories, like all ideas in science, are subject to correction.


  • Examples:

    • Plate Tectonic Theory

    • Atomic Theory of Matter

    • Germ Theory of Disease

    • Music Theory

    • Gravitational Theory

    • Theory of Molecular Genetics

    • Theory of Natural Selection

Diversity of life
Diversity of Life

  • Life is found almost everywhere on earth.

    • There are organisms that live in hydrothermal vents in the deepest part of the ocean, in thousands-of-years-old Antarctic ice.

The biosphere
The Biosphere

  • All living things and all the places they are found on Earth make up the biosphere.

    • Every part of the biosphere is connected to another.


  • The variety of life in the biosphere is biodiversity.

    • Greater biodiversity is usually found near the equator.

      • Why do you think this is?

  • Over 2 million species have been identified, but scientists estimate that tens of millions of species are left to be identified.

    • Every year, biologists discover about 10,000 new species.

Characteristics of living things
Characteristics of Living Things

  • Biology is the scientific study of all forms of life, or all types of organisms.

  • An organism is any individual living thing.

    • Which of these is a living thing? Why is it living and the other non-living?

Characteristics of living things1
Characteristics of Living Things

  • All living organisms share these characteristics:

    • They are made of cells.

    • They need energy.

    • They respond to their environment.

    • They reproduce and grow.

    • They maintain a stable internal environment.

    • They change over time.

Unifying themes
Unifying Themes

  • Biology has several unifying themes:

    • All levels of life have systems of related parts.

    • Structure and function are related in biology.

    • Organisms must maintain homeostasis to survive in diverse environments.

    • Adaptation over time explains the unity and diversity of life.

Biology is a process of inquiry
Biology is a Process of Inquiry

  • Scientific thinking begins with observation.

    • Observation uses the senses—hearing, sight, smell, etc.

    • It involves repeatedly recording the information over time.

Thinking like a scientist
Thinking Like a Scientist

  • Over time, data is gathered.

    • Qualitative data = descriptions and involves characteristics that can’t usually be counted.

    • Quantitative data = expressed as numbers, obtained by counting or measuring.

Thinking like a scientist1
Thinking Like a Scientist

  • From a large amount of data—an Inference is made.

    • An Inference is a logical interpretation of phenomena

    • It is based on prior knowledge or experience.

Explaining and interpreting evidence
Explaining and Interpreting Evidence

  • After initial observations—a scientist will from one or more Hypotheses.

  • A hypothesis is:

    • Based on prior knowledge

    • Based on inference

    • Informed

    • Creative and Imaginative


      • Controlled experiments

      • Collecting more data

Spontaneous generation
Spontaneous Generation

  • Up until the late 1800’s some people believed that life generated from non-life.

Redi s experiment
Redi’s Experiment

OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat.

HYPOTHESIS: Flies produce maggots.


Uncovered jars

Covered jars

Controlled Variables:

jars, type of meat,

location, temperature,



days pass

Manipulated Variables:

gauze covering that

keeps flies away from


Responding Variable:

whether maggots


Maggots appear

No maggots appear

CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.

Spallanzani s experiment
Spallanzani’s Experiment

  • Spallanzani tested Redi’s results with an experiment of his own.

Flask is


Gravy is teeming

with microorganisms.

Gravy is boiled.

Flask is


Gravy is free of


Gravy is boiled.

Pasteur s experiment
Pasteur’s Experiment

Broth is boiled.

Broth is free of


for a year.

Curved neck

is removed.

Broth is teeming with microorganisms

Modern tools of biology
Modern Tools of Biology

  • Microscopes

  • Medical Imaging

  • Modeling on computers

  • Molecular Genetics

    • The study and manipulation of DNA.

    • Genomics = the study and comparison of genomes within and across species.

Biology and your future
Biology and Your Future

  • Food

    • 70-75 % of processed food contains some genetically engineered ingredients.

    • 45% of U.S. corn is genetically engineered.

    • 60% of adults in the U.S. are overweight or obese.

Biology and your future1
Biology and Your Future

  • Environment and health

    • Recent studies have indicated that chemicals present in re-used water can cause hormonal deformities in certain plant and animal species.

    • It has been suggested that hormones present in certain meat products can cause children to hit puberty quicker.

Biology and your future2
Biology and Your Future

  • Biotechnology

    • Includes the use of microorganisms to make bread and cheese.

    • Used in medicine, agriculture, forensic science, and many other fields.

      • The use of DNA testing in criminal courts is an example of biotechnology.

Biology and your future3
Biology and Your Future

  • Transgenic Organisms

    • Organisms that have genes from more than one species, or have altered copies of their own genes are transgenic organisms.

      • Transgenic bacteria is used to create insulin that treats diabetes.

      • Transgenic cows and sheep create antibodies and proteins that humans can use.

      • Transgenic plants are resistant to insects and can reduce or end the need of pesticides.

Biology and your future4
Biology and Your Future

  • Genetic Screening

    • These tests can indicate whether individuals or their potential offspring may be at risk for certain diseases or genetic disorders.

      • This can help with early diagnosis and treatment.

    • Who should have access to the information? What genetic quirks should be considered disorders? Could genetic information be used to design children?

Science as a way of knowing
Science as a Way of Knowing

  • Science is not a collection of immutable truths.

  • Science is an ongoing process.

  • Scientists need to be skeptical, open minded, and analytical.

  • Science and human values often intersect. The knowledge we collect today affects the lives of people tomorrow.