01. Biology the Science of Life

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Unit I

Chemical & Cellular Basis of Life

Biology: The Science of Life

OVERVIEW

BIOLOGY is a science that attempts to understand the diversity of life

on earth, of which we, human beings are a part of. What is LIFE?

LIFE is not a simple concept.

Living organisms are manifestations of life in that they exhibit

certain general properties that we recognize as the definition of life.

Living organisms are built by assembling large molecules that

include carbohydrates & lipids (molecules that give energy),

proteins (molecules that speed up specific chemical reactions), and

nucleic acids (molecules in which hereditary information is stored)

All organisms are made up of CELLS, some are composed of singlecell and some, like us, are composed of many cells.

Among the cell’s most important activities are its transactions with

the environment, a give-and-take that never stops.

OUTLINE

A. Biology As A Science

1. Definition of Biology

2. Development as a Science

3. Methods of Biology4. Branches of Biology

B. Nature of Life

1. Theories on the Origin of Life2. Characteristics of Living Things

BIOLOGY AS A SCIENCE

A. Definition of Biology

Comes from 2 Greek words: bios = life + logus = to study

The science of life

The study of living things

Deals with the investigation of the origin, history,

structure, function, identification, classification,

distribution, development, inheritances, and significance

of living things as well as their relationships and

interactions with the environment

B. Development of Biology As A Science

From Copernicus to Newton, the focus was on the physical sciences. Little attentions were given to some important biological discoveries

and inventions.

a. Vesalius (1543) – human anatomy

b. Harvey (1628) – circulation of blood

c. Malphigi (1661) – blood capillaries

d. Robert Hooke (1665) – cell

e. Van Leeuwenhoek (1674) – microscopy

f. Schwann (1838), Schleiden (1839), & Virchow (1858) – cell theory

Attention was turned to biological science when Charles Darwin, anEnglish naturalist, published the ―Origin of Species‖ in 1859, which

marked the birth of the modern era of biology.

This was followed by:

a. Louis Pasteur (1865) – rejection of spontaneous generation theory

b. Gregor Mendel (1866) – genetics d. Watson & Crick (1953) – DNAc. Knoll & Ruska 1935 – electron microsco e

C. Methods of Biology

As a science, biology also uses the scientific method in solving orinvestigating a biological problem.

Scientific Method is the logical process of learning facts through

observation and experimentation from which, certain conclusions or

theories are drawn.

Steps of the Scientific Method:

1. Identification of the problem

2. Formulation of hypotheses

3. Experimentation or testing of hypotheses

4. Analysis and interpretation of data and results5. Generalization or formulation of conclusion

1. Identification of the Problem

Any scientific process starts with observation using all

the senses.

From observation, a problem may be identified.

2. Formulation of Hypotheses

A set of assumptions or possible explanations to the

problem will be formulated.

Hypothesis is a preliminary conclusion or scientific

guess about the problem.

Steps of the Scientific Method: 3. Experimentation or Testing of Hypotheses

Experiment is a special procedure used to test the hypotheses,

There must be 2 sets of experiments

a. Control Set-Up

b. Experimental Set-Up: similar to the control set-up in every

aspect except the presence of the variable

The variable is the factor or parameter to be tested.

4. Analysis and Interpretation of Data and ResultsData or results must be gathered during and after experimentation.

Data include records collected while making observations during

an experiment.

One way to analyze or interpret records of observation is by using

tables and graphs.

5. Generalization or Formulation of Conclusion

Based from the analyzed data, a theory may be

formulated supported by experimental evidence.

The theory may be developed into a scientific law or

into a principle.

Theory is a synthesis of a large body of information that

encompasses well-tested and verified hypotheses about

certain aspects of the natural world.

Law is a general hypothesis or statement about the

relationship of natural quantities that has been tested

over and over again and has not been contradicted. It is

also known as a principle.

Limitations of the Scientific Method: 1. Existence of God

Differences Between Science & Religion:

a. Science is concerned with understanding the physical universe,

while religion is concerned with spiritual matters, such as belief

and faith in, and the worship of, a supreme being and the creation

of human community — not the practice of science.

b. Scientific truth is a matter of public scrutiny while religion is a

deeply personal matter.

Similarities Between Science & Religion:a. Both are motivated by curiosity for the natural.

b. Both have great impact on society. Science, for example, leads to

useful technological innovations, while religion provides a

foothold for many social services.

2. Beaut a reciation

Limitations of the Scientific Method: 2. Beauty appreciation

Differences Between Science & Art:

1. ART is about creative communication of ideas and emotions while

SCIENCE is about establishing truth or finding objective facts through

verifiable experimentation.

2. ART seeks aesthetic response while SCIENCE seeks knowledge

and understanding.

3. ART is subjective while SCIENCE is objective.

4. ART is conceptual, while SCIENCE is theoretical5. ART needs no proof since it cannot be proved. On the other hand,

SCIENCE is based upon theories and hypothesis, and every phenomenon

or device can be explained through science.

6. ART is the representation of human thought while SCIENCE is

the representation of natural order. ARTISTS who express a new ideamust communicate it to their audience for ustification. SCIENTISTS

Differences Between Science & Art:

a. ART is about creative communication of ideas and emotions while

SCIENCE is about establishing truth or finding objective facts

through verifiable experimentation.

b. ART seeks aesthetic response while SCIENCE seeks knowledge

and understanding.

c. ART is subjective while SCIENCE is objective.

d. ART is conceptual, while SCIENCE is theoreticale. ART needs no proof since it cannot be proved. On the other hand,

SCIENCE is based upon theories and hypothesis, and every

phenomenon or device can be explained through science.

ART is the representation of human thought while SCIENCE is the

representation of natural order. ARTISTS who express a new idea mustcommunicate it to their audience for ustification. SCIENTISTS who

Similarities between Art & Science. Both ART & SCIENCE:

a. Value the careful observation of their environments to gather

information through the senses.

b. Value creativity.

c. Propose to induce change, innovation, or improvement over what

exists.

d. Use abstract models to understand the world.

e. Aspire to create works that have universal relevance.

3. Moral issues

4. Value judgment – scientists may become biased based on their

beliefs

D. Branches of Biology

According to Methods of Aspect of Study:1. Anatomy – dissection of body parts

2. Physiology - functions

3. Biogeography – distribution of living things

4. Cytology – cells

5. Ecology – interactions and relationships within an ecosystem

6. Embryology – development of the embryo

7. Evolution – origin of species

8. Genetics - heredity

9. Histology – tissues10. Limnology – fresh water habitats

11. Oceanography – marine water habitats

12. Organology - organs

13. Paleontology – fossils/evidences of the past

14. Pathology – diseases15. S stematics – identification & classification

According to Methods of Aspect of Study:16. Taxonomy – classification

17. Nomenclature – naming/assigning of scientific name

According to Type of Organisms:

1. Botany – plants

2. Zoology – animals

3. Mammalogy – mammals

4. Ichthyology – fishes

5. Helminthology – worms

6. Herpertology – reptiles and amphibians7. Carcinology – crustaceans

8. Malacology – mollusks

9. Microbiology - micoorganisms

10. Bacteriology – bacteria

11. Mycology – fungi12. Parasitolo – arasites

According to Type of Organisms:

13. Virology – viruses

14. Protozoology – protozoans

15. Ornithology – birds16. Phycology – algae

17. Entomology – insects

E. Unifying Theories of Biology

1. Cell Theory

2. Biogenesis

3. Homeostasis

4. Evolution5. Gene

NATURE OF LIFE

A. Theories on the Origin of Life

1. Divine Creation Theory

2. Cosmozoic or Interplanetary Theory

3. Philosophical Theory of Eternity

4. Abiogenesis or Spontaneous Generation Theory5. Big Bang Theory

NATURE OF LIFE

1. Divine Creation TheoryBased on the book of Genesis in the Bible (story of

Creation

Life is believed to have been created by the AlmightyGod.

NATURE OF LIFE

2. Cosmozoic or Interplanetary TheoryA protoplasm in the form of a resistant spore

originated from outer planets propelled by radiation

pressureThe spore reached the Earth and started the first

form of life

3. Philosophical Theory of EternityLife has no beginning and no end; life has been there

right from the very beginning of time

NATURE OF LIFE

4. Abiogenesis or Spontaneous Generation TheoryLife originated spontaneously from non-living things

Disproved by Francesco Redi, an Italian scientist in

1668, and Louis Pasteur, a French chemist in 1865

5. Big Bang TheoryAlso called the Physico-chemical or Cosmological

Theory

Most scientific and most accepted theory

Developed in the 1940s by George Gamow and R. A.Alpher

Heavenly bodies, including the Earth, originated from

the explosion of a hot rotating ball of gas and eventually

life was formed from the chemical evolution of differentcom ounds resent in the rimitive earth

NATURE OF LIFE

B. Characteristics of Living Things

1. Metabolism

2. Growth

3. Irritability

4. Reproduction & Development5. Adaptation

6. Organization

7. Assimilation8. Definite Form & Size

8. Definite Chemical Composition

NATURE OF LIFE

1. MetabolismRefers to all the chemical and energy

transformations that occur in cells as they carry out

life’s processes A must in order to maintain their organization, and

to grow and reproduce

Can be:

1.1 Anabolism – building up process1.2 Catabolism – breaking down process

NATURE OF LIFE

2. Growth

Refers to an increase in size

Accomplished through a complex series of

chemical processes (intussusception)Occurs when constructive activities occur at

a faster rate than destructive properties

NATURE OF LIFE

3. Irritability

Refers to the ability to react to any

environmental change or stimulus that often

results in movementAnother form of response is when living

things find energy and nutrients by

interacting with their surroundingsThe ability to respond helps ensure the

survival of the organisms

NATURE OF LIFE

4. Reproduction and Development

Life comes only from life.

In order for life to continue, living things

must be able to produce other living things of their kind (reproduction)

Can be:

4.1 Sexual Reproduction4.1 Asexual Reproduction

NATURE OF LIFE

5. Adaptation

Refers to modifications that promote the

likelihood of survival

Living things not suited to a new conditioneither move to a better environment or

change (evolution

A change cannot occur in one generation butover many generations

Results into unity and diversity and life

NATURE OF LIFE

Can be:

NATURE OF LIFE

5. Organization

Part of living things are arranged in a

particular way

There are levels of biological organization1) Atoms

2) Molecules

3) Cells4) Tissues

5) Organs

6) Organ System

NATURE OF LIFE

Can be:

NATURE OF LIFE

Can be:

NATURE OF LIFE

Can be:

NATURE OF LIFE

Can be:

NATURE OF LIFE

Can be:

01. Biology the Science of Life

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