Chapter 1 Biology and You

Everyone is a Biologist ! Biologist – a person who studies biology Biology – the study of LIFE Bio- = life -logy = study of

Topics for consumption… What are the characteristics of life? How do we describe the diversity of living things? How do we go about the study of life?

What are the characteristics of life?

Characteristics of Life Cellular structure and function Reproduction Metabolism Homeostasis Heredity Evolution Interdependence

Cellular Structure and Function All living things are made of one or more cells The cell is the smallest unit of life Cells have a highly ordered structure Cells Tissues Organs Organ Systems

Reproduction All living things reproduce (make more of themselves) Reproduction is essential to the survival of the species Asexual reproduction - involves a single parent; progeny are genetically identical to the parent. Sexual reproduction - involves 2 parents; progeny are genetically diverse.

Metabolism The sum of all the chemical reaction in the body or cell Provides energy for all life functions Important Processes ATP Cycling Photosynthesis Cellular Respiration

Homeostasis The ability of an organism to maintain its internal environment despite conditions in the external environment.

Heredity Defined as the ability to pass on traits to offspring Hereditary information is stored in our DNA (deoxyribonucleic acid) found in the cell Genes - sets of instructions for making proteins and the mechanism for passing on traits Mutations - any change in a gene; can be positive, negative or neutral Mutations that occur in the sex cells will be passed down to the next generation; mutations occurring in somatic (other body cells) will not

Evolution Defined as change in inherited traits of a species over time Species - any group of genetically similar (same type/number of genes) individuals that can produce fertile offspring (offspring that can reproduce) Individuals with favorable genes are more likely to live, reproduce and pass on their genes; making those traits more prominent in the population. Darwin called this natural selection. Adaptation - an inherited behavior or characteristic that enables an organism to survive & reproduce.

Interdependence Organisms interact with and often depend on each other Ecology - the study of these interactions

Biology Advances in Everyday Life Living in harmony with our environment Humans can be very destructive to the environment; therefore biologists are learning how to Conserve current natural resources Learn about and from extinct species Restore a more natural balance in the environment Feeding a growing population To produce enough food biologists are Learning how to Grow crops more efficiently, protecting them from disease, drought, and infestation Genetically engineering (altering) plants to make them stronger

Fighting disease AIDS - (Acquired Immune Deficiency Disorder); caused by HIV (Human Immunodeficiency Disorder) People who have developed AIDS can not fight off otherwise non-lethal diseases Biologists study the transmission and progression of this disease in order to stop the spread and attempt to treat and maybe someday cure this condition Cancer Occurs when cells divide uncontrollably Biologists study the processes of cell division to develop treatments and have identified many underlying causes of this condition allowing prevention a many cases Cystic Fibrosis Attacks the lungs of the affected causing the body to produce a thick sticky mucus that impairs breathing, also affects many other organs functioning Biologists now know this is a genetic disorder passed on from parent to child Currently in development are gene therapies that may one day cure this ailment, this would hopefully replace the painful and limited treatments available today

How do we describe the diversity of living things?

Categorizing Organisms Biodiversity refers to the many different types of organisms on earth. Taxonomy is the biological science that classifies life according to evolutionary relationships. The Domain is the largest group of organisms and can be divided into six kingdoms.

Seven Levels of the Taxonomy Kingdom Phylum Class Order Family Genus Species Kings Play Chess On Funny Green Squares Keep Pots Clean Or Family Gets Sick

How do we go about the study of life?

The Scientific Process/Method Scientific Method of Investigation - Organized framework followed for most scientific studies Six common stages: a. Collecting observations: act of noting or perceiving objects or events using the senses b. Asking questions: who, what, where, when, how, and why c. Forming a hypothesis: an explanation that might be true and Making a prediction: an expected outcome of a test assuming your hypothesis is correct d. Confirming predictions: proving your hypothesis/predictions to be true or false through observation, research, or experimentation e. Drawing conclusions: determining if your hypothesis has been confirmed or rejected (NOT PROVEN!) f. Sharing results: through publication or other public means

The Scientific Experiment A planned process to test a hypothesis Controlled experiments have the following elements: Control group – receives no experimental treatment Experimental group - receives the experimental treatment Independent variable – the factor that is varied of changed Dependent variable – the factor that is measured (will be affected by the independent variable)

Levels of scientific thought… What is difference between hypothesis, theory & law? Hypothesis - “an educated guess”; a tentative explanation of phenomena. Theory - a widely accepted explanation of natural phenomena; has stood up to thorough & continual testing. Law - a statement of what always occurs under certain conditions.