Chapter 1 Biology And You

Section 1: Themes of Biology Objectives  Relate the 7 properties of life to a living organism.  Describe 7 themes that can help you organize what you learn about biology.  Identify the tiny structures that make up all living organisms.  Differentiate between reproduction and heredity and between metabolism and homeostasis.  Relate the 7 properties of life to a living organism.  Describe 7 themes that can help you organize what you learn about biology.  Identify the tiny structures that make up all living organisms.  Differentiate between reproduction and heredity and between metabolism and homeostasis.

Characteristics of Living Organisms  Biology is the study of life  Life is characterized by the presence of specific criteria.  All of the properties must be present at one point in the organisms life.  Biology is the study of life  Life is characterized by the presence of specific criteria.  All of the properties must be present at one point in the organisms life.

7 Unifying themes of Biology 1.Cellular structure and function 2.Reproduction 3.Metabolism 4.Homeostasis 5.Heredity 6.Evolution 7.Interdependence 1.Cellular structure and function 2.Reproduction 3.Metabolism 4.Homeostasis 5.Heredity 6.Evolution 7.Interdependence

Cellular structure and function  All living things are made of one or more cells.  Cells are highly organized, tiny structures with thin coverings called membranes.  Some cells are more complex than others and some organisms only have one cell, where we have over 100 trillion cells.  All living things are made of one or more cells.  Cells are highly organized, tiny structures with thin coverings called membranes.  Some cells are more complex than others and some organisms only have one cell, where we have over 100 trillion cells.

Reproduction  All living things can reproduce.  Reproduction is the process by which organisms make more of their own kind from one generation to the next.  All living things can reproduce.  Reproduction is the process by which organisms make more of their own kind from one generation to the next.

Metabolism  All living things use energy to grow, to move, and to process information.  Metabolism is the sum of all of the chemical reactions carried out in an organism.  Almost all the energy originates from the sun.  All living things use energy to grow, to move, and to process information.  Metabolism is the sum of all of the chemical reactions carried out in an organism.  Almost all the energy originates from the sun.

Homeostasis  All living organisms must maintain a stable environment in order to survive.  Homeostasis is the maintenance of stable internal conditions in spite of changes in the external environment.  Can you think of another example other than the harp seal?  All living organisms must maintain a stable environment in order to survive.  Homeostasis is the maintenance of stable internal conditions in spite of changes in the external environment.  Can you think of another example other than the harp seal?

Heredity  All living things are able to pass on traits to their offspring through genes.  A gene is the basic unit of heredity which determine an organisms traits. (DNA)  Heredity is the passing of traits from parent to offspring.  All living things are able to pass on traits to their offspring through genes.  A gene is the basic unit of heredity which determine an organisms traits. (DNA)  Heredity is the passing of traits from parent to offspring.

Heredity cont.  Mutations can occur within in genes. It is a change in the DNA of a gene.  Most are harmful, few can be beneficial.  Example: Sickle cell anemia.  Sex cell mutations-passed on  Body cells mutations-not passed on  Mutations can occur within in genes. It is a change in the DNA of a gene.  Most are harmful, few can be beneficial.  Example: Sickle cell anemia.  Sex cell mutations-passed on  Body cells mutations-not passed on

Evolution  Evolution is the change in the inherited characteristics of species over generations. –Species: a group of genetically similar organisms that can reproduce fertile offspring.  Evolution is the change in the inherited characteristics of species over generations. –Species: a group of genetically similar organisms that can reproduce fertile offspring.

Evolution continued  When individuals pass on favorable traits to their offspring, those traits become more common, and make the organism more likely to reproduce and survive; this is called natural selection.  Charles Darwin is the scientist that developed the theory of evolution by natural selection.  When individuals pass on favorable traits to their offspring, those traits become more common, and make the organism more likely to reproduce and survive; this is called natural selection.  Charles Darwin is the scientist that developed the theory of evolution by natural selection.

Interdependence  All living organisms are interdependent with one another.  Ecology is the branch of biology that studies interactions of organisms with one another and with the nonliving parts of their environment.  All living organisms are interdependent with one another.  Ecology is the branch of biology that studies interactions of organisms with one another and with the nonliving parts of their environment.

Section Review Questions

Section 2: Biology in Your World Objectives  Evaluate the impact of scientific research on the environment.  Evaluate the impact of scientifc research on society with the respect to increasing food supply.  Explain the primary task of the Human Genome Project.  Describe the contributions of scientists in fighting AIDS and cancer.  Define the term gene therapy.  Evaluate the impact of scientific research on the environment.  Evaluate the impact of scientifc research on society with the respect to increasing food supply.  Explain the primary task of the Human Genome Project.  Describe the contributions of scientists in fighting AIDS and cancer.  Define the term gene therapy.

Preserving our Environment  With the increasing populations on Earth, we are having a significant impact on other organisms we share the planet with.  Conservationist biologists are finding ways to achieve a balance between our growing need for land and the need to preserve the environment.  With the increasing populations on Earth, we are having a significant impact on other organisms we share the planet with.  Conservationist biologists are finding ways to achieve a balance between our growing need for land and the need to preserve the environment.

Improving the food supply  With genetic engineering, scientists have discovered ways of making some crops resistant to herbicides so when the herbicide is sprayed on the weeds, it does not kill the crop.  The addition of genes from other plants to add more nutrition to rice.  With genetic engineering, scientists have discovered ways of making some crops resistant to herbicides so when the herbicide is sprayed on the weeds, it does not kill the crop.  The addition of genes from other plants to add more nutrition to rice.

Understanding the Human Genome  A genome is the complete genetic material contained in an individual.  Human genome: 3 billion individual units.  The gene sequence allows scientists to create a road map of human genes. –Figure 11, pg 11  A genome is the complete genetic material contained in an individual.  Human genome: 3 billion individual units.  The gene sequence allows scientists to create a road map of human genes. –Figure 11, pg 11

Fighting Disease  Scientists are making incredible scientific advances curing diseases and improving health.  New technologies are available now to combat diseases that were considered incurable years ago.  Scientists are making incredible scientific advances curing diseases and improving health.  New technologies are available now to combat diseases that were considered incurable years ago.

AIDS  Fatal disease caused by HIV.  HIV is a virus that attacks and destroys the human immune system.  Scientists have had difficulty trying to find a cure because the virus alters itself too frequently when it passes from one person to the next.  Fatal disease caused by HIV.  HIV is a virus that attacks and destroys the human immune system.  Scientists have had difficulty trying to find a cure because the virus alters itself too frequently when it passes from one person to the next.

Cancer  Caused from a defect in the mechanism that controls cell growth.  We now know that many cancers can be avoided(smoking), while others can be treated successfully when caught early.  Much progress is being made.  Caused from a defect in the mechanism that controls cell growth.  We now know that many cancers can be avoided(smoking), while others can be treated successfully when caught early.  Much progress is being made.

Emerging diseases  West Nile virus- not in US until 1999 –Transmitted by mosquitoes –Infects birds, humans, horses, and possibly others  Mad cow disease- in Europe –Caused from cows eating infected animals, they’re fed supplement proteins from other parts of cows  Similar condition in US that affects elk and deer  West Nile virus- not in US until 1999 –Transmitted by mosquitoes –Infects birds, humans, horses, and possibly others  Mad cow disease- in Europe –Caused from cows eating infected animals, they’re fed supplement proteins from other parts of cows  Similar condition in US that affects elk and deer

Section Review Questions

Section 3: Scientific Process Objectives  Describe the stages common to scientific investigations.  Distinguish between forming a hypothesis and making a prediction.  Differentiate a control from an experimental group and an independent variable from a dependent variable.  Define the word theory as used by scientists  Describe the stages common to scientific investigations.  Distinguish between forming a hypothesis and making a prediction.  Differentiate a control from an experimental group and an independent variable from a dependent variable.  Define the word theory as used by scientists

Scientific Method  Observations  Hypotheses  Predictions & Experiments  Theories  Observations  Hypotheses  Predictions & Experiments  Theories

Using the scientific method  EX: Tiger salamanders numbers dropped by 65%  Live in ponds on the western slopes of the Rockies  Wanted to find out why.  EX: Tiger salamanders numbers dropped by 65%  Live in ponds on the western slopes of the Rockies  Wanted to find out why.

Observation  The act of noting or perceiving objects or events using the senses.  He kept good records for years of the salamanders habits, eating, reproduction, behavior.  Asking questions- why did the number drop? He talked to other scientists –Thought acid rain had something to do with it  The act of noting or perceiving objects or events using the senses.  He kept good records for years of the salamanders habits, eating, reproduction, behavior.  Asking questions- why did the number drop? He talked to other scientists –Thought acid rain had something to do with it

Hypothesis  An explanation that might be true- a statement that can be tested by additional observations or experiments.

2 Hypotheses 1.Acids that were formed in upper atmosphere by pollutants were falling onto the mountains in the winter snows. 2.Melting snow was making the ponds acidic and harming the salamander embryos. 1.Acids that were formed in upper atmosphere by pollutants were falling onto the mountains in the winter snows. 2.Melting snow was making the ponds acidic and harming the salamander embryos.

Prediction  The expected outcome of a test, assuming the hypothesis is correct.  He predicted he would find acid in the pond after the snow melted.  And there would be enough acid in the pond to harm the embryos  The expected outcome of a test, assuming the hypothesis is correct.  He predicted he would find acid in the pond after the snow melted.  And there would be enough acid in the pond to harm the embryos

Confirming predictions  He used a pH scale 0-14 that indicates the hydrogen ion concentration  Figure 16, pg 16  Mapped his data  The pH rose then leveled off  This confirmed his first hypothesis  He used a pH scale 0-14 that indicates the hydrogen ion concentration  Figure 16, pg 16  Mapped his data  The pH rose then leveled off  This confirmed his first hypothesis

Experiment  A planned procedure to test a hypothesis  Salamanders only lay eggs at the same time of year as the snow melts.  He performed an experiment to determine if the acidic water affected the embryos of the salamanders  A planned procedure to test a hypothesis  Salamanders only lay eggs at the same time of year as the snow melts.  He performed an experiment to determine if the acidic water affected the embryos of the salamanders

Parts of an experiment  Control group-no experimental treatment  Experimental group: receives treatment  Independent variable: the factor that is changed in the experiment (pH level)  Dependent variable: what is measured (number of hatched eggs)  Control group-no experimental treatment  Experimental group: receives treatment  Independent variable: the factor that is changed in the experiment (pH level)  Dependent variable: what is measured (number of hatched eggs)

pH Experiment: 5 groups  1 Control group- eggs in neutral pH  4 Experimental groups –Each group had different levels of acid that were found after the snow melt.  He found many did not hatch after being in the acidic water.  1 Control group- eggs in neutral pH  4 Experimental groups –Each group had different levels of acid that were found after the snow melt.  He found many did not hatch after being in the acidic water.

Drawing conclusions  Based on the data, determine whether or not it supports or rejects the hypothesis  His data supported both of his hypotheses  He concluded that melting snow could cause acid to be released into the water at snowmelt, harming embryos  Based on the data, determine whether or not it supports or rejects the hypothesis  His data supported both of his hypotheses  He concluded that melting snow could cause acid to be released into the water at snowmelt, harming embryos

Scientific Explanations  Hypotheses will either be rejected or supported.  Once several hypotheses have been supported, tested and confirmed, it becomes a theory.  Sometimes theories may not be accepted with all scientists at first, but if it is well supported, over time it may gain acceptance.  Hypotheses will either be rejected or supported.  Once several hypotheses have been supported, tested and confirmed, it becomes a theory.  Sometimes theories may not be accepted with all scientists at first, but if it is well supported, over time it may gain acceptance.

Constructing a theory  The research must be capable of replicating the theory by other scientists.  Theories can always be revised or rejected over time, but it is a well-supported scientific explanation that makes useful predictions.  Work is published for review by peers.  The research must be capable of replicating the theory by other scientists.  Theories can always be revised or rejected over time, but it is a well-supported scientific explanation that makes useful predictions.  Work is published for review by peers.