chapter: exploring and classifying life table of contents section 3: where does life come from?where...

Chapter: Exploring and Classifying Life

Table of ContentsTable of Contents

Section 3: Where does life come from?

Section 1: What is science?

Section 2: Living Things

Section 4: How are living things classified?

• Science - An organized way of studying things and finding answers to questions.

The Work of Science

What is science? What is science?

11

• Physics – Relationship between energy and matter

Types of Science


11

• Biology – Study of Living things

• Botanists – Plants

• Zoologists - Animals

Critical Thinking


11

•Identify and solve problems

Solving Problems


11

• Scientific Method - series of procedures to solve problems

Solving Problems


11

• Control - Standard to which the outcome of a test is compared.

Controls


11

• Variable - Thing in an experiment that can change.

• Share information

Report Results


11

Developing Theories


11

• Theory – explanation based on scientific knowledge

•Result of many observations and experiments.

• Law - Statement about how things work in nature that seems to be true all the time.

Laws


11

• Less likely to change than theories.

Measuring with Scientific Units


11

Measuring with Scientific Units


11

• Called the International System of Units, or SI.

• Laboratory safety – Requirement of the Class

Safety First


11

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11Section CheckSection Check

Question 1

This diagram shows a way to use scientific methods to solve a problem. According to the diagram, if a hypothesis is not supported by data then you should _______.


A. change the data so that they do support the hypothesis B. find a different problem to solveC. propose a scientific theoryD. revise the hypothesis and perform new experiments


Answer

The correct answer is D. Scientific methods are an organized way to solve a problem in science. This series of procedures involves forming a hypothesis that can be tested.


Question 2

What is the definition of a control in a scientific experiment?

Answer

A control is the standard to which the outcome of a test will be compared. Controls help you determine how to interpret your data.


Question 3

A statement about how things work in nature that seems to be true all the time is a _______.

A. conclusion B. hypothesisC. lawD. variable


Answer

The correct answer is C. Although laws can be modified as more information becomes known, they are less likely to change than theories.

What are living things like?

• Organism - living thing.• Have similar traits.

Living ThingsLiving Things

22

Living Things Are Organized

• Cell - Smallest unit of an organism that carries on the functions of life.


22

Living Things Respond

• Interact with surroundings.

• Stimulus – Causes change


22

• Response – Reaction to stimulus

Living Things Respond


22

• Homeostasis - Ability to maintain internal stability

Living Things Use Energy


22

•All energy comes from the Sun

Living Things Use Energy


22

Living Things Grow and Develop• Growth - Increase in number of

cells or size of cells


22

• Development – Physiological Changes

Living Things Reproduce


22

• Organisms create offspring to maintain a population

A Place to Live


22

• Surroundings provide for all an organism’s needs.

Raw Materials


22

• You are made of 60 to 70 percent water.

Raw Materials• Organisms – Made mostly of proteins, fats,

and sugars.


22

• Materials – Recycled when organisms die


Question 1

What is the smallest unit in a cat that carries on the functions of life?

AnswerThe cell is the smallest unit. All organisms are composed of cells. Cells take in materials from their surroundings and use them in complex ways.


Question 2

Pulling your hand back when you accidentally touch a hot pan on the stove is an example of what characteristic of living things?

A. growth and development B. organizationC. reproductionD. response to stimuli


Answer

The correct answer is D. The hot pan is an example of a stimulus. Living things can respond to both external and internal stimuli.


Question 3

Give an example of two raw materials that you need to survive.

Answer

Some possible answers include: water, food, and oxygen. Some bacteria and plants can make food from raw materials in their surroundings.

Life Comes from Life

• Spontaneous generation – Original theory that organisms came from nonliving sources

Where does life come from?Where does life come from?

33

• Biogenesis - Living things come only from other living things


This diagram shows an experiment Louis Pasteur conducted with boiled broth and S-necked flasks. Why did microbes only grow in the bottom flask?

Question 1


Microbes from the air settled out at the bottom of the S-neck and only entered the broth when it was tilted so that the broth touched this area. This experiment by Pasteur helped disprove the theory of spontaneous generation.

Answer


Which one of the following examples supports the theory of biogenesis?

Question 2

A. kittens are produced from cats B. milk is produced by cowsC. rain is produced by rain cloudsD. stimuli produce responses


The correct answer is A. The theory of biogenesis states that living things come only from other living things.

Answer


What did Alexander Oparin suggest about Earth’s early atmosphere?

Question 3


He suggested that it contained no oxygen but was made up of the gases ammonia, hydrogen, methane, and water vapor. He hypothesized that these gases could have combined to produce compounds found in living things.

Answer

Classification

How are living things classified?How are living things classified?

44

• Classification - Organizing things into groups.

History of Classification• Aristotle – Organized organisms into

plants and Animals


44

• Animals - hair or no hair, four legs or few legs, and blood or no blood.

Linnaeus

• Carolus Linnaeus – Grouped organisms based on similarities


44

Modern Classification

• Scientists study

• Fossils

• Hereditary information

• Early stages of development.


44

• Phylogeny - Evolutionary history of an organism (How it has changed over time)

Six Kingdoms• A kingdom is the first and largest category.


44

Six Kingdoms


44

• Species- Organisms that can mate and produce fertile offspring.

Binomial Nomenclature

• Binomial nomenclature

• Two-word naming system

• Developed by Linnaeus


44

Binomial Nomenclature


44

• Genus - group of similar species.

• Species – a group of organisms that produce fertile offspring

Tools for Identifying Organisms

• Dichotomous keys – Give 2 choices that lead to classification


44


Question 1

Over 2,000 years ago, Aristotle developed a system to classify all organisms _______.

A. as either plant or animal.B. based on fossils. C. into six different kingdoms.D. using binomial nomenclature.


Answer

The correct answer is A. Aristotle broke these two groups into smaller groups. Two of his smaller groups of animals would have been animals with hair and those with no hair.


Question 2

What word is used to describe the evolutionary history of an organism?

Answer

The word is phylogeny. Phylogeny explains how an organism has changed over time and is the basis for the modern classification of many organisms.


Question 3

Acer rubrum is the scientific name for a red maple tree. This name is an example of _______.

A. a dichotomous key B. a hypothesisC. binomial nomenclatureD. spontaneous generation


Answer

The correct answer is C. Binomial nomenclature is the system used by modern scientists to name organisms. The first part of the scientific name identifies the genus of the organism.

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chapter: exploring and classifying life table of contents section 3: where does life come from?where...

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