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Inquiry into Life, 10th edition

bySylvia Mader

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

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Chapter 1: The Study of Life

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The Characteristics of Life

Life is diverse yet all living things share common characteristics.

• Living things are organized.

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• Living things acquire materials and energy.

Photosynthetic organisms use carbon dioxide, water, and solar energy to make food.

Animals obtain nutrients and energy from food eaten.

Energy is the capacity to do work.

Many living things can convert energy to motion.

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• Living things reproduce.

Genes (DNA) contain information needed for heredity and metabolism.

Metabolism is all the chemical reactions in the cell.

Reproduction may be asexual or sexual.

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• Living things respond to stimuli.

Living things may respond to external stimuli by movement toward or away from a stimulus.

Movement constitutes part of the behavior of an organism.

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• Living things are homeostatic.

Homeostasis is the ability of an organism to maintain relatively constant internal conditions.

An example is temperature regulation in the human body.

All organ systems contribute to homeostasis.

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• Living things grow and develop.

All organisms undergo development.

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• Living things are adapted. Adaptations come about through

evolution. Evolution is the process by which a

species changes through time. Evolution explains both the unity and

diversity of life.

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The Classification of Living Things • Taxomony is the science of identifying

and classifying organisms according to specific criteria using these categories:

Kingdom Phylum (Division) Class Order Family

Genus

Species

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There are three domains:

Archaea and Bacteria – unicellular prokaryotes that lack a membrane-bound nucleus.

Eukarya – showing cellular complexity and having a nucleus and other organelles.

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Archaea live in harsh environments and may represent the first cells to

have evolved.

Bacteria, some of which cause human diseases, are present in almost all

habitats on earth.

Many bacteria are important environmentally and commercially.

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The Domain Eukarya is divided into 4 kingdoms:

Protists (kingdom Protista)

Fungi (kingdom Fungi)

Plants (kingdom Plantae)

Animals (kingdom Animalia)

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Most genera contain a number of similar species, with the exception of Homo that only contains modern humans.

Classification is based on evolutionary relationships.

Each successive classification category contains more different types of organisms than the preceding category.

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Scientific names are binomial names, using genus and species.

Modern humans are Homo sapiens.

 

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The Organization of the Biosphere

The biosphere is the zone of life in the air, water, and land that surrounds the planet.

Groups of individuals of a species are called populations.

Populations of different species that interact make up communities.

Communities plus the physical habitat form ecosystems.

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Ecosystems are characterized by chemical cycling and energy flow.

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Climate determines what ecosystem can exist in an area.

Human populations tend to modify ecosystems for their uses.

Loss of ecosystems results in loss of biodiversity, the total number of species.

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Preservation of ecosystems is important to ensure our continued existence.

Loss of species threatens ecosystems.

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The Process of Science

Biology, the study of life, uses the scientific method.

The scientific method has these steps: Observation Hypothesis Experiments/Further Observations Conclusion Theory

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An experimental design contains a control group that goes through all the steps of the experiment but is not exposed to the factor being tested.

Results of an experiment are called data.

Data undergo statistical evaluation.

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Several theories in biology include:

Cell

Biogenesis

Evolution

Gene

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Scientific studies may be carried out in the field or in the lab.

In either type of study, scientists formulate testable hypotheses, make observations or perform experiments, and come to objective conclusions.

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Field Study Example

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Controlled Laboratory Experiment Example

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Science and Social Responsibility

Technology is the application of knowledge for a practical purpose.

Technology has both benefits and drawbacks.

Ethical and moral issues surrounding the use of technology must be decided by everyone.