Chapter 23Chapter 23Section 2Section 2

Advances in ScienceAdvances in ScienceAnd Medicine And Medicine

Cell Theory in BiologyCell Theory in Biology Biological SciencesBiological Sciences are sciences that deal with

living organisms such as genetics, zoology, botany and biology

Physical SciencesPhysical Sciences are sciences that deal with the properties of nonliving matter and energy such as chemistry, astronomy, geology and physics

Scientists of the 1800’s were interested in explaining the nature of life as well as the nature of nonliving matter

Early observers, with the help of microscopes, saw what we now know as plant and animal cells.

They noticed that all species cells were different shapes and sizes

But they did not fully understand or draw any general conclusions

Cells from an Elodea Plant

Human Brain Cells Dog Kidney Cells

Continued….Continued…. Finally in 1838, a German botanist and a German Finally in 1838, a German botanist and a German

biologist clearly expressed cell theorybiologist clearly expressed cell theory They stated that all living things are made up of They stated that all living things are made up of

tiny living matter and that all cells divide and tiny living matter and that all cells divide and multiply causing the organism to grow and maturemultiply causing the organism to grow and mature

In the 1850’s another German scientist expanded In the 1850’s another German scientist expanded on the theory by stating that every new cell must on the theory by stating that every new cell must come from some older cell therefore only living come from some older cell therefore only living matter can produce new living matter matter can produce new living matter

Thus accepting the cell as the basic unit of living Thus accepting the cell as the basic unit of living mattermatter

Lamarck’s Theory of Lamarck’s Theory of Inheritance Inheritance

Many scientists believed that plants and animals Many scientists believed that plants and animals that live today had developed from common that live today had developed from common ancestors from long agoancestors from long ago

This kind of development through change is called This kind of development through change is called evolutionevolution

French biologist Jean-Baptiste Lamarck suggested his theory of inheritance and evolution through adaptation.

Some of Lamarck’s theories were later proved to be wrong and did not become a part of modern biology

But he did influence other scientists such as a But he did influence other scientists such as a British naturalist named Charles Darwin British naturalist named Charles Darwin

Darwin’s Theory of Darwin’s Theory of Evolution Evolution

Charles Darwin Charles Darwin began his theories with a well-known fact: no two living things are exactly alike not even a parent and its offspring

Darwin combined this fact with the idea that as a result of natural dangers that there will always be more creatures born than can survive

Those that survive will then be the best of the species that can adapt to the environment around them.

They will then produce offspring that possess the characteristics so they can pass them on to future generations

Darwin thought that in this way he could explain the evolution of all forms of life from previous forms

The theory of natural selection was controversial because it stated that human beings developed from animals.

However Darwin felt that his theory of evolution did not challenge the existence of God

““There is grandeur in There is grandeur in this view of life…having this view of life…having been originally breathed been originally breathed by the Creator into a by the Creator into a few forms or into one; few forms or into one; and that….from so and that….from so simple a beginning simple a beginning endless forms most endless forms most beautiful and most beautiful and most wonderful have been wonderful have been and are being evolved” and are being evolved” -Charles

Darwin

GeneticsGenetics An Austrian monk named Gregor Mendel founded An Austrian monk named Gregor Mendel founded

genetics,genetics, or the study of how characteristics of plants and animals are passed and inherited by their descendants

He began his experiments by crossbreeding tall plants with short plants. To Mendel’s surprise he got tall plants and not medium sized plants

From these experiments Mendel concluded that inborn traits were not blended together. Instead they were all inherited as if they were separate particles

And in some cases a trait could be carried but not And in some cases a trait could be carried but not expressedexpressed

For example: the tall plant could pass the For example: the tall plant could pass the “particles” on to the next generation making one “particles” on to the next generation making one or some of its offspring shortor some of its offspring short

The Fight Against DiseaseThe Fight Against Disease Until the late 1800’s as many as 50% of the population Until the late 1800’s as many as 50% of the population

born died within the first five years after birthborn died within the first five years after birth Smallpox was one of the deadliest diseases Smallpox was one of the deadliest diseases An English physician named Edward Jenner developed a An English physician named Edward Jenner developed a

vaccine for smallpox by the way of exposure to another vaccine for smallpox by the way of exposure to another milder disease called cowpox milder disease called cowpox

Jenner did create a vaccine but he did not know exactly Jenner did create a vaccine but he did not know exactly why it workedwhy it worked

Later a French chemist, {Later a French chemist, {Louis PasteurLouis Pasteur, identified , identified microorganisms called bacteria microorganisms called bacteria

In the 1860’s Pasteur developed the process of heating In the 1860’s Pasteur developed the process of heating liquids to kill bacteria and prevent fermentation in a liquids to kill bacteria and prevent fermentation in a process called process called pasteurizationpasteurization} }

Pasteur also created a vaccine that prevented animals Pasteur also created a vaccine that prevented animals from contracting the germ that causes anthrax. Leading from contracting the germ that causes anthrax. Leading him to the conclusion that when weakened germs enter him to the conclusion that when weakened germs enter the body that your body builds up antibodies to fight them the body that your body builds up antibodies to fight them

Advances in Surgery and Advances in Surgery and Medicine Medicine

In the 1840’s medicinal purposes for ether and In the 1840’s medicinal purposes for ether and chloroform were discovered, making longer chloroform were discovered, making longer operations possibleoperations possible

However, people still died from infection However, people still died from infection afterward afterward

Until a surgeon named Until a surgeon named {Joseph Lister developed {Joseph Lister developed antisepsis, antisepsis, or the use of chemicals to kill germs}or the use of chemicals to kill germs}

The use of these antiseptics helped to reduce the The use of these antiseptics helped to reduce the number of infections after surgerynumber of infections after surgery

As people began to realize the sources of diseases As people began to realize the sources of diseases such as malaria and the Bubonic Plague they such as malaria and the Bubonic Plague they discovered ways of preventing themdiscovered ways of preventing them

During this time Aspirin and Insulin were inventedDuring this time Aspirin and Insulin were invented Alexander FlemingAlexander Fleming discovered penicillin in 1928 discovered penicillin in 1928

although penicillin drugs were not widely although penicillin drugs were not widely available until the 1940’s available until the 1940’s

The Atom and it’s StructureThe Atom and it’s Structure Although knowledge of atoms can be traced back to the Although knowledge of atoms can be traced back to the

1500’s it had not been proven yet1500’s it had not been proven yet A school teacher named John Dalton created a way to A school teacher named John Dalton created a way to

“weigh” atoms in 1803“weigh” atoms in 1803 Much later in 1869 a Russian chemist, Much later in 1869 a Russian chemist, Dmitry Dmitry

Mendeleyev,Mendeleyev, expanded on this and created the first expanded on this and created the first periodic tableperiodic table

It was expanded upon throughout the years by It was expanded upon throughout the years by chemists such as {chemists such as {Pierre and Marie CuriePierre and Marie Curie who who experimented with radium and plutonium. experimented with radium and plutonium. They found They found that these elements constantly break down and release that these elements constantly break down and release energy on their own in a process called energy on their own in a process called radioactivityradioactivity}}

Elements that release energy this way are called Elements that release energy this way are called radioactive elementsradioactive elements

Later evidence was found about electrons and the Later evidence was found about electrons and the nucleus, protons and neutrons. nucleus, protons and neutrons.

Plank and Einstein Plank and Einstein Before 1900 scientists believed that energy was a Before 1900 scientists believed that energy was a

exponential substance, and it could be divided into any exponential substance, and it could be divided into any number of smaller units number of smaller units

In 1900 In 1900 Max PlanckMax Planck disproved this with his disproved this with his quantum quantum theorytheory in which he proved that energy could only be in which he proved that energy could only be released in “definite packages”released in “definite packages”

{Albert Einstein{Albert Einstein in studying Planck’s work developed his in studying Planck’s work developed his special theory of relativityspecial theory of relativity which states that no particles which states that no particles of matter can move faster than the speed of light}of matter can move faster than the speed of light}

Einstein also developed the famous equation, E=mc2. Einstein also developed the famous equation, E=mc2. Where he expressed the relationship between energy and Where he expressed the relationship between energy and massmass

Einstein also declared that this is not just a three Einstein also declared that this is not just a three dimensional universe but a fourth dimension (time) existed.dimensional universe but a fourth dimension (time) existed.

Einstein called his 4-dimensial system the space-time Einstein called his 4-dimensial system the space-time continuum. continuum.

Review QuestionsReview Questions This man identified microorganisms called This man identified microorganisms called

bacteria bacteria Pasteur developed the process of heating Pasteur developed the process of heating

liquids to kill bacteria what was it called?liquids to kill bacteria what was it called? Joseph Lister developed ___________, or the use Joseph Lister developed ___________, or the use

of chemicals to kill germsof chemicals to kill germs Who found that certain elements constantly Who found that certain elements constantly

break down and release energy on their own in break down and release energy on their own in a process called radioactivitya process called radioactivity

Who developed the theory of relativity which Who developed the theory of relativity which states that no particles of matter can move states that no particles of matter can move faster than the speed of lightfaster than the speed of light

"The release of atom "The release of atom power has changed power has changed everything except our everything except our way of thinking...the way of thinking...the solution to this solution to this problem lies in the problem lies in the heart of mankind. If heart of mankind. If only I had known, I only I had known, I should have become a should have become a watchmaker." watchmaker."

-Albert Einstein on the bomb