Chapter 1 Biology and You Biology I Mrs. Mead

Welcome to BIOLOGY!

Section 1 Objectives “Themes of Biology” Relate the seven properties of life to a living organism. Identify the tiny structures that make up all living organisms. Differentiate between reproduction and heredity and between metabolism and homeostasis.

What is BIOLOGY??? Biology is the study of life. “Bios” = Life “Logos” = Study Biologists recognize that all living organisms share certain general properties that separate them from nonliving things. They study: 1. The interactions of life. 2. The interactions with the environment. 3. Problems and propose solutions. (EX: Medical treatment, disease prevention.

What is an ORGANISM??? All living things are organisms.

7 Properties of Life Organization and Cells Reproduction Metabolism Homeostasis Heredity Responsiveness to Stimuli Growth and Development/Change over Time

1. Organization and Cells All living things are composed of one or more cells. These tiny structures make up all living organisms. Each cell contains DNA. All parts function together in an orderly system.

2. Reproduction Reproduction: The process by which organisms make more of their own kind. Reproduction is an essential part of living. Why??? Because no organism lives forever!!!

3. Metabolism All living things use energy to grow, to move, and to process information. Without energy, life soon stops! Metabolism: The sum of all chemical reactions carried out in an organism.

4. Homeostasis Homeostasis: Maintaining stable internal conditions, in spite of change, that are suitable for survival. (Takes Energy!!!) Organisms respond to changes in their external environment, and their internal processes adjust accordingly.

5. Heredity All living things are able to pass on traits to their offspring through genes that are passed on from parents to offspring. Gene: the basic unit of heredity. The passing of traits from parent to offspring is called heredity.

6. Responsiveness to Stimuli Stimulus: Any condition that requires a response. Response: Reaction to a stimulus. What is the stimulus and what is the response?

7. Growth and Development Changes over Time Growth: A gradual increase in size over time. Results in more living material and forms new structures. Development: All the changes that take place during the life of an organism. Adaptation: Any structure, behavior or internal process that enables an organism to respond to stimuli better and better survive in an environment. Evolution: Gradual accumulation of adaptations over time. Evolution is just a change over time.

7. Growth and Development Changes over Time

How is life so DIVERSE? The great diversity of life on Earth is the result of a long history of change. Change in the inherited characteristics of species over generations is called evolution. A species is a group of genetically similar organisms that can produce fertile offspring. The process in which organisms with favorable traits are more likely to survive and reproduce is called natural selection. Charles Darwin used this term to describe genetic traits that better enable organisms to meet natures challenges.

Evolution The ancient sifrhippus, the earliest known horse, lived around 50 million years ago. It was very distinct in its appearance because it was only about the size of a modern day house cat, weighing in around 12 pounds.

Interdependence Organisms in a biological community live and interact with other organisms. A biological community is a group of interacting organisms. Ecology is the branch of biology that studies the interactions of organisms with one another and with the nonliving part of their environment.

Section 1 Objectives “Themes of Biology” Relate the seven properties of life to a living organism. Identify the tiny structures that make up all living organisms. Differentiate between reproduction and heredity and between metabolism and homeostasis.

Section 2 Objectives “Biology in Your World” Evaluate the impact of scientific research on the environment. Evaluate the impact of scientific research on society with respect to increasing food supplies. Describe the contributions of scientists in fighting disease.

Preserving Our Environment The increasing human population has had a significant impact on other organisms that are share this planet with. One of the great achievements of today’s biology has been to show the practical benefits of taking better care of our environment. Conservation and preservation are now everyday activities of government, industry, and individuals.

Preserving Our Environment

Improving the Food Supply Biologists have learned how to transfer genes from one kind of plant to another. Genetic engineering has made some crop plants resistant to herbicides. So that weeds can be killed without harming the food crop.

What is the Human Genome? Genome: the complete genetic material contained in an individual. The human genome contains 3 billion units! Biologists are able to read every human gene, providing them with a detailed map of genes. It will be years before this information is fully understood. Why is this useful???

Fighting Disease Progress in biology directly affects our lives through medicine, in which scientific advances are curing disease and improving health every day. New technologies have enabled biologists to combat disease in ways scarcely imagined only a few years ago. Consider: AIDS and Cancer.

Fighting Disease - AIDS For more than 20 years, biologist have been battling AIDS. AIDS: a fatal disease caused by HIV, which is a virus that attacks and destroys the human immune system. Biologists have been successful at developing a combination of drugs that slow the progression, but have not found a way to successfully halt its spreading.

Fighting Disease - AIDS The AIDS virus attacks the immune system, leaving a person vulnerable to a wide host of life- threatening diseases. The World Health Organization (WHO) classifies HIV as a pandemic, an infectious epidemic that has spread over multiple continents. The WHO estimates that there are over 34 million people diagnosed with HIV worldwide.

Fighting Disease - Cancer Cancer: a growth defect in cells. We now know that many cancers can be avoided. Lung Cancer – DON’T SMOKE!!! Skin Cancer – DON’T TAN ALL THE TIME!!! Many cancers have extra copies of proteins– some anticancer drugs can stick to these extra cell proteins gumming them up so that they cannot promote excessive cell division.

Fighting Disease - Cancer Cancer cells are the cells that acquired the ability of chaotic division and it is not possible to return them to their normal functions. Cancer cells live their own lives, regardless of the rules and regulations in the cell community and following only their own needs for persistent growth.

Gene Therapy Biologists have searched for years for a way to introduce “healthy” genes into people suffering from hereditary disorders. Cystic fibrosis is one candidate. A fatal disorder in which a thick, mucus clogs passages in many of the body’s organs.

Section 2 Objectives “Biology in Your World” Evaluate the impact of scientific research on the environment. Evaluate the impact of scientific research on society with respect to increasing food supplies. Describe the contributions of scientists in fighting disease.

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

Scientific Processes Science is characterized by an organized approach, called the scientific method, to learn how the natural world works. Although there is no single method for doing science, scientific studies involve a series of common steps.

Scientific Theory Steps 1. Observation 2. Hypothesis 3. Experiment 4. Conclude

Scientific Theory Steps 1. Observation The act of perceiving a natural occurrence that causes someone to pose a question. 2. Hypothesis A proposed explanation for the way a particular aspect of the natural world functions. 3. Prediction A statement that forecasts what would happen in a test situation if the hypothesis were true. 4. Experiment Used to test a hypothesis and its predictions. 5. Analyze Once the experiment has been conducted, analyze data. 6. Verify, reject, or modify conclusions. Communicate results to scientific peers and to the public.

Scientific Theory

What is an EXPERIMENT??? A planned procedure to test a hypothesis. Two groups are needed: Control Group Experimental Group Must have a control group: a group in an experiment that receives no experimental treatment. Control groups and experimental groups are designed to be identical except for one variable. Two types of variables:  Independent Variable: the factor that is changed.  Dependent Variable: the factor that is measured due to change.

Scientific Processes Scientists add to scientific knowledge by sharing observations and posing questions about those observations. In a controlled experiment, the independent variable is varied between the experimental and control groups. The measured variable is the dependent variable. A collection of hypothesis that have been repeatedly tested and are supported by a great deal of evidence forms a theory.

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