Ch 1 PPT - Mr. B's Science Pagemrbssciencepage.weebly.com/.../ch_1_the_science_of_biology_ppt.pdf · between organisms and nonliving things. 9/1/2016 29 9 Characteristics of Living

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1. Review‐What is ScienceExplain‐What kinds of understandings does science contribute about the natural world

Form an Opinion‐ Do you think that scientists will ever run out of things to study, explain your reasoning

2. A few hundred years ago, observations seemed to indicate that some living things could just suddenly appear: maggots showed up on meat; mice were found on grain; and beetles turned up on cow dung. Those observations led to the incorrect idea of spontaneous generation‐ the notion that life could arise from non living matter. Write a paragraph for a history magazine evaluating the spontaneous generation hypothesis. Why did it seem logical at the time? What evidence was overlooked or ignored?

THE SCIENCE OF BIOLOGY

1.1 What Is Science?

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Where did plants and animals come from

How did I come to be

Humans have tried to answer these questions in different ways. Some ways of explaining the world have stayed the same over time. Science, however, is always changing.

What Science Is and Is Not

What are the goals of science?

To provide natural explanations for events in the natural world

To use those explanations to understand patterns in nature and to make useful predictions about natural events.

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What Science Is and Is Not

Biology is not just a collection of never‐changing facts or unchanging beliefs about the world

Some scientific “facts” will change soon—if they haven’t changed already – and scientific ideas are open to testing, discussion, and revision.

Science as a Way of Knowing

Science

An organized way of gathering and analyzing evidence about the natural world

Researchers can use science to answer questions about how whales communicate, how far they travel, and how they are affected by environmental changes.

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Science as a Way of Knowing

Science deals only with the natural world

Scientists collect and organize information in an orderly way, looking for patterns and connections among events

Scientists propose explanations that are based on evidence, not belief. Then they test those explanations with more evidence.

The Goals of Science

To provide natural explanations for events in the natural world

To use those explanations to understand patterns in nature and to make useful predictions about natural events.

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Science, Change, and Uncertainty

Almost every major scientific discovery raises more questions than it answers

Science rarely “proves” anything

Allows us to build enough understanding to make useful predictions about the natural world.

Scientific Methodology

Observing and asking questions

Making inferences and forming hypotheses

Conducting controlled experiments

Collecting and analyzing data

Drawing conclusions.

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Observing and Asking Questions

Observation

The act of noticing and describing events or processes in a careful, orderly way.

Observing and Asking QuestionsExample

Researchers observed that marsh grass grows taller in some places than others. This observation led to a question: Why do marsh grasses grow to different heights in different places?

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Making Inferences and Forming Hypotheses

Inferences

Logical interpretations based on what is already known.


Hypothesis

Statement that explains an Observation

Tested with experiments

Can be proved false

Can NOT be proved true.

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Hypothesis MUST contain

What you are measuring

What you are changing

What you think will happen.


Researchers inferred that something limits grass growth in some places. They hypothesized that marsh grass growth is limited by available nitrogen.

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Designing Controlled Experiments

Testing a scientific hypothesis often involves designing an experiment that keeps track of various factors that can change, or variables

Examples of variables include temperature, light, time, and availability of nutrients.

Controlled Experiment

An experiment when only ONE variable is changed and the rest are all kept constant or unchanged.

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Variable

Things that are or could be different in the experiment

Want to have them all the same except one

Why?

Controlling Variables

It is important to control variables because if several variables are changed in the experiment, researchers can’t easily tell which variable is responsible for any results they observe.

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Dependent VariableWhat is measured, What occurs, Y axis

Independent VariableWhat you are changing or testing, X axis.

Control and Experimental Groups

Control

The base, thing you haven’t changed, what it normally is

Used so you can compare your result with what normally should occur

Experimental Groups

The same as the control group except for the one independent variable.

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Researchers selected similar plots of marsh grass. All plots had similar plant density, soil type, input of freshwater, and height above average tide level.


Researchers added nitrogen fertilizer (the independent variable) to the experimental plots. They then observed the growth of marsh grass (the dependent variable) in both experimental and control plots.

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Collecting and Analyzing Data

Scientists record experimental observations, gathering information called data

Two main types of data

Quantitative data

Qualitative data.


Quantitative Data

Numbers obtained by counting or measuring. In the marsh grass experiment‐ i.e. Number of plants per plot, plant sizes, and growth rates‐ Preferred data type

Qualitative Data

Descriptive and involve characteristics that cannot usually be counted‐ Notes about foreign objects in the plots, or whether the grass was growing upright or sideways.

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Sources of Error

Data collection

Tools used to measure the size and weight of marsh grasses, for example, have limited accuracy

Data analysis

The larger the sample size the more reliable the data.


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Drawing Conclusions

Scientists use experimental data as evidence to support, refute, or revise the hypothesis being tested, and to draw a valid conclusion

Marsh grasses grew taller than controls by adding nitrogen.

Drawing Conclusions

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Experiments Are Not Always Possible

Observations are then used

Examples

How animals interact in the wild

Ethical issues especially with people.

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1. Review‐What is a scientific theoryCompare and Contrast‐ How does use of the word theory differ in science and in daily life

2. Review‐What is peer reviewApply Concepts‐ An advertisement claims that studies of a new sports drink show it boosts energy. You discover that none of the study results have been peer‐reviewed. What would you tell consumers who are considering buying this product

3. Review‐ How is the use of science related to its context in societyApply Concepts‐ A study shows that a new pesticide is safe for use on food crops. The researcher who conducted the study works for the pesticide company. What potential biases may have affected the study

THE SCIENCE OF BIOLOGY

1.2 Science in Context

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Exploration and Discovery: Where Ideas Come From

What scientific attitudes help generate new ideas

Curiosity, skepticism, open‐mindedness, and creativity.

Exploration and Discovery: Where Ideas Come From

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Curiosity

“What’s that plant? Why is it growing here?”

Skepticism

Question existing ideas and hypotheses, and they refuse to accept explanations without evidence

Open‐Mindedness

Willing to accept different ideas that may not agree with their hypothesis

Creativity

Design experiments that yield accurate data.

The Role of Technology

Technology in one field may lead to new discoveries in another field

Technologies may have big impacts in your daily life‐ it is now possible to mass produce complex molecules like antibiotics and hormones.

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The Role of Technology

Communicating Results: Reviewing and Sharing Ideas

Scientists share their findings with the scientific community by publishing articles

Scientific papers are reviewed by anonymous, independent experts looking for oversights, unfair influences, fraud, or mistakes in techniques or reasoning.

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Communicating Results: Reviewing and Sharing Ideas

Sharing Knowledge and New Ideas

Once research has been published, it may spark new questions, experiments, and discoveries

The findings that growth of salt marsh grasses is limited by available nitrogen suggests that nitrogen might be a limiting nutrient for mangroves and other plants in similar habitats.

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Scientific Theories

A broad and comprehensive statement of what is thought to be true

It is supported by considerable evidence and may tie together several related hypotheses

Is only accepted after it has been supported by a vast body of experimental data.

Theory vs. Law

Theory

Take many pieces of data to explain how or why something happens

Law

States a relationship between two phenomena.

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Science and Society

Scientific questions may involve the society in which we live, our economy, and our laws and moral principles

Researchers can test shellfish for toxins that can poison humans. Should shellfish be routinely screened for toxins?

Science, Ethics, and Morality

Scientists can explain “why” something happens

Pure science does not include ethical or moral viewpoints

Science can tell us how technology and scientific knowledge can be applied but not whether it should be applied in particular ways.

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Science, Ethics, and Morality

Bias

Science aims to be objective

However, scientific data can be misinterpreted or misapplied by scientists who want to prove a particular point

Bias

Particular preference or point of view that is personal, rather than scientific.

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Understanding and Using Science

Don’t just memorize today’s scientific facts and ideas

Understand how scientists developed those ideas

Understanding biology will help you realize that we humans can predict the consequences of our actions and take an active role in directing our future and that of our planet.

Understanding and Using Science

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Quick lab

Replicating Procedures

1. Working with a partner behind a screen, assemble ten blocks into an unusual structure. Write directions that others can use to replicate that structure without seeing it

2. Exchange directions with another team. Replicate the team’s structure by following its directions

3. Compare each replicated structure to the original. Identify which parts of the direction were clear and accurate, and which were unclear or misleading.

Quick lab

Analyze and Conclude

1. Evaluate‐ How could you have written better directions

2. Infer‐Why is it important that scientists write procedures that can be replicated?

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1. Review‐What are the themes in biology that come up again and again

Predict‐ Suppose you discover a new organism. What would you expect to see if you studied it under a microscope

2. Review‐ At what levels do biologists study life

Classify‐ A researcher studies why frogs are disappearing in the wild. What field of biology does the research fall

3. Practice‐ In an experiment, you need 250 grams of potting soil for each of 10 plant samples. How many kilograms of soil in total do you need?

SCIENCE OF BIOLOGY

1.3 Studying Life

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• Think about important news stories you’ve heard. Bird flu spreads around the world, killing birds and threatening a human epidemic. Users of certain illegal drugs experience permanent damage to their brains and nervous systems. Reports surface about efforts to clone human cells.

• These and many other stories involve biology—the science that employs scientific methodology to study living things. The Greek word bios means “life,” and ‐logy means “study of.”

Characteristics of Living Things

What characteristics do all living things share

No single characteristic is enough to describe a living thing

Some things, such as viruses, exist at the border between organisms and nonliving things.

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9 Characteristics of Living Things

A universal genetic code

DNA.


Grow and develop

Single fertilized egg divides again and again

They differentiate, which means they perform different functions.

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Respond to their environment

Stimulus: signal to which an organism responds.


Reproduce

Most plants and animals engage in sexual reproduction

Cells from two parents unite to form the first cell of a new organism

Asexual reproduction

Single organism produces offspring identical to itself.

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Maintain homeostasis

Relatively stable internal environment.


Metabolism

Obtain and use material and energy to grow, develop, and reproduce.

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Made up of one or more cells

Cells can grow, respond to their surroundings, and reproduce

Cells are complex and highly organized.


Groups of organisms evolve.

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Big Ideas in Biology

Cellular basis of life

Information and heredity

Matter and energy

Growth, development, and reproduction

Homeostasis

Evolution

Structure and function

Unity and diversity of life

Interdependence in nature

Science as a way of knowing.

Fields of Biology

Global Ecology

Biotechnology

Building the Tree of Life

Ecology and Evolution of Infectious Diseases

Genomics and Molecular Biology

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Scientific Measurement

Scientists use the metric system when collecting data and performing experiments.


1 kilometer = ___ meters

.45 liters = ___milliliters

5000 milligrams = ___grams

130 meters = ___ kilometers

2500 milliliters = ___liters

.017 grams = ___milligrams

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1 kilometer = 1000meters

.45 liters = ___milliliters






1 kilometer = 1000 meters

.45 liters = 450milliliters





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.45 liters = 450 milliliters

5000 milligrams = 5 grams








130 meters = .13 kilometers



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2500 milliliters = 2.5 liters







2500 milliliters = 2.5 liters

.017 grams = 17milligrams

Ch 1 PPT - Mr. B's Science Pagemrbssciencepage.weebly.com/.../ch_1_the_science_of_biology_ppt.pdf · between organisms and nonliving things. 9/1/2016 29 9 Characteristics of Living

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