Observation: The process of gathering information, in a ...blog.wsd.net/jfiliaga/files/2009/09/Chap-1-The-Nature-of-Science... · •Science is characterized by the systematic gathering

• Observation: The process of

gathering information, in a

careful orderly way.

Prediction vs Hypothesis

• Predictions are meant to be proven once.

• A hypothesis can still end up as a

hypothesis even if it has already proven.

– Another scientific inquiry might prove it

contrary in the future.

Disclosure

• Find it on Mr. Filiaga’s blog.

– http://blog.wsd.net/jfiliaga

Fee

• $10.00

– Pay it at the book keeper

• Science is characterized by the

systematic gathering of information

through various forms of direct and

indirect observations and the testing of

this information by methods including,

but not limited to, experimentation. The

principal product of science is

knowledge in the form of naturalistic

concepts and the laws and theories

related to those concepts. (NSTA)

Vocab Chapter 11. Science

2. Scientific method

3. Theory

4. Hypothesis

5. Observation

6. Data

7. Inference

8. Controlled experiment

9. Manipulated variable

10. Responding variable

11. Biology

12. Cell

13. Microscope

14. Compound light

Microscope

15. Cell culture

16. Metric system

17. Unicellular

18. Multicellular

19. Sexual reproduction

20. Asexual reproduction

21. Metabolism

22. Stimulus

23. Homeostasis

The Nature of Science

• A process for gaining

knowledge

• The main goal

–Understand the natural

world.

• The scientific method is a

science process for solving

science problems.

–It involves a variety of methods

and may not always use the

same procedures.

Science findings are based upon evidence.

Empirical evidence (scientific process)

Evidence is influenced by natural laws

which are constant

Conclusions are subject to change

Hypothesis

Theory

Predictions

Test

Consistent

Not consistent

Modify hypothesis

• Hypothesis = A proposed

explanation for a set of

observations.

–a tentative statement about

the natural world.

– need to be able to test

• Theory explanation of some aspect of the natural world

It tries to unify a broad range of observations.

It is a well-tested explanation–A hypothesis that has withstood the test

of time.

–Must be validated by the scientific community before it is accepted.

• A theory has a much stronger

meaning.

–broadly based concepts that make

sense of a large body of observations

and experimentation.

– successfully tie together such a huge

amount of information, they are among

the most important ideas in science.

• Theories do not become laws even

with additional evidence

–they explain laws

• not all scientific laws have

accompanying explanatory theories

–Laws differ from Theories

• Laws do not assume a mechanism or

explanation of phenomena

Scientific Laws

• Laws are generalizations or universal

relationships related to the way that

some aspect of the natural world

behaves under certain conditions.

–A phenomenon of nature that has

been proven to consistently occur

• Scientific facts are observable

phenomenon in a particular situation.

–"Dinosaurs were cold-blooded"

• cannot be observed

–"The caterpillar is 2.6 cm in length“

•a fact, because the phenomenon can

be observed in a particular situation

• Quantitative data is information about

quantities; can be measured and written

down with numbers.

• Qualitative data is information about

qualities; information that can't actually be

measured. • The age of your car.

• The number of hairs on your knuckle.

• The softness of a cat.

• The color of the sky.

• The number of pennies in your pocket.

Data: facts and statistics collected together

for reference or analysis

What is an inference

• a conclusion reached on the basis of

evidence and reasoning.

–Logical interpretation.

• An inference is made when you combine

a new observation with what you already

know to form a conclusion.

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

HYPOTHESIS: Flies produce maggots.

PROCEDURE

Controlled Variables:jars, type of meat,location, temperature,time

Manipulated Variables:gauze covering thatkeeps flies away from meat

Uncovered jars Covered jars

Several days pass

Maggots appear No maggots appear

Responding Variable: whether maggots appear

CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous

generation of maggots did not occur.

Spontaneous GenerationRedi concluded that this theory is not a plasuible theory

Parts of a controlled experiment

• Controlled variable is constant

• The Manipulated variable is the

independent variable

• The Responding variable is the

dependent variable

PROCEDURE

Controlled Variables:jars, type of meat,location, temperature,time

Manipulated Variables:gauze covering thatkeeps flies away from meat

Uncovered jars Covered jars

Several days pass

Maggots appear No maggots appear

Responding Variable: whether maggots appear

Biology

• Bio = living

• logy = the study of

• Organization

–There are many levels at which to study living things.

•Smaller systems are found within larger systems.

Biosphere

Ecosystem

Community

Population

Organism

Groups of cells

Cells

Levels of

organization

The part of

Earth

that contains all

ecosystems

Community and

its nonliving

surroundings

Populations that

live together in

a

defined area

Group of

organisms of one

type that live in

the same area

Biosphere

Hawk, snake, bison, prairie dog, grass, stream, rocks, air

Hawk, snake, bison, prairie dog, grass

Bison herd

Cells

Individual living

thing

Tissues,

organs,

and organ

systems

Smallest

functional

unit of life

Groups of atoms;

smallest unit of

most chemical

compounds

Bison

Nervous tissueNervous system

Brain

Nerve cell

Water

DNA

Important Tools and Techniques

• A microscope is used to see objects

that are too small for the naked eye.

• The compound light microscope

–Can study living cells and small organisms

–Disadvantage is its limit of resolution (1000x)

–Most commonly used in biology

• The electron microscopes

– The limit of resolution allows them to magnify objects about 1000x greater

– The disadvantage is that all specimens are dead

• Many specimens are stained or dyed

– increase the visibility

• Because of the Microscope

– Microscopy, Microbiology, Micro-organisms.

– The Germ Theory.

– Microdissection

• A technique where a microscope is used to assist in dissection.

• Cell Fractionation is the process used to

separate cellular components

– Still perserves individual functions of each

component.

Centrifugation• Process used to separate cells or cell parts.

• Separates things by their weight (density).

• Heavier things fall to the bottom.

• Cell fractionation breaks up the cell parts

–Then spun in a centrifuge.

• Cell culture is a process that can grow many cells to study.

• A single cell is placed in an environment that allows it to grow and replicate.

• *

• The Metric System

–The system of measurement used

by scientist.

–The system is based on powers or

multiples of 10

• Mass vs. weight

• Mass is the amount of matter

• Weight is the measurement of the

force of gravity

–Basic units of measure

• Liter = liquid volume

• Cubic centimeters = solid volume

• Meter = length

• Kilogram = mass

• Celsius = temp

–water freezing point = 0o

–water boiling point = 100o

• Lab safety is important

• The most important, when in a lab, follow the instructions exactly.

• Lab agreement and safety rules:

You must know and follow all safety

rules in the lab.

• Find it on Mr. Filiaga’s blog.

– http://blog.wsd.net/jfiliaga

Shells and Snowflakes

• How can we distinguish between living and

nonliving things, such as a radiolarian (left)

and a snowflake (right)?

• A radiolarian is a tiny living thing that is

covered with a glasslike shell and lives in

the ocean.

• A snowflake is a crystal made of frozen

water.

Characteristics of Life1. Living things are made up of cells

– The cell is the basic unit of function in all

living things

– A cell is a collection of living matter

• It is enclosed by a barrier that

separates it from its environment.

• Unicellular: one cell, many

microorganisms consist of a single

cell

• Multicellular: many cells, animals and

trees are multicellular

2. Living things grow and develop

– Growth rates will vary

– Development will vary

– Growth stops at death

– Flies begin life as eggs, then become maggots,

and then become adult flies

– Taken as a group living things change over

time

• Evolution – genetic change over time

• Plants that live in the desert survive because they

have become adapted to the conditions of the desert

3. Living things can obtain and use energy

– Some have very specialized systems for

obtaining energy

– Metabolism includes all the reactions that

build up and break down

• Anabolism: builds up

• Catabolism: breaks down

– Plants obtain their energy form sunlight

• autotrophs

– Animals obtain their energy from the food they

eat

• heterotrophs

4. Living things can reproduce

– Reproduction occurs as a means of

continuing the species.

– There are two types of reproduction.

• Asexual: a single organism reproduces w/o the aid

of another.

– It is a less complicated process

– Offspring are identical to parent

• Sexual: requires two cells from two different

organisms.

– Off spring are similar but not identical.

– Living things are based on a universal genetic

code that is passed on during reproduction.

• Flies produce flies, dogs produce dogs, maple

seeds produce maple trees.

5. Living things respond to their

environment

– In response living things try to maintain

a stable internal environment.

• Homeostasis, balance between

internal systems and the environment

– temperature Hot / Cold

– Irritability: the ability to respond to a

stimulus

– Stimulus is anything that causes a

response

• Humans need to maintain a body temp of

37º C.

• Branches of Biology

–Life on earth is very

diverse

• Zoology studies

• Mamology studies

• Ichthyology studies

• Entomology studies

• Ornithology studies

• Botany studies

• Microbiology studies

• Paleontology studies

• All sciences are interrelated and interconnected.

– The need for evidence seperates science from non-science.

– Common rules of evidence

• Inquiry characteristics:

–Logic

–Precision

–Open-mindedness

–Objectivity

–Skepticism

–Replicability of results

–Honesty

–Ethical reporting of findings

Ethics• Mitochondrial replacement removes

faulty mitochondrial DNA

–can cause inherited conditions such

as fatal heart problems, liver failure,

brain disorders, blindness and

muscular dystrophy.

–About 1 in 6,000 babies around the

world are born with serious

mitochondrial disorders.

Science and technology may raise ethical issues for which science cannot provide solutions for.

3-Parent IVF Babies

Pro:

– Can “cure” several genetic

diseases.

Con:

– Ethical treatment of

embryo?

– Genetically manipulated

humans?