1 The Science of Life

2 What is Biology? Biology is the study of all living things Living things are called organisms Living things are called organisms Organisms include bacteria, protists, fungi, plants, & animals

Biology and….. Biology and You Biology and You -healthy foods -healthy foods -exercise and reproduction -exercise and reproduction -DNA -DNA Biology and Society Biology and Society -ecosystems -ecosystems -animal/plant interactions -animal/plant interactions -pollution and water supply -pollution and water supply -curing disease -curing disease 3

4 All Living Things Share Common Characteristics 1. Basic Unit is the Cell and cells are organized. 2. They Reproduce and have DNA. 3. Grow & Develop

5 Common Characteristics 4. Obtain & Use Materials & Energy (Metabolism) (Metabolism) 5. Respond To Their Environment 6. Maintain A Stable Internal Environment (Homeostasis) 7. AS A GROUP, Living Things Evolve, That Is They Change Over Time

6 Characteristics of Organisms

7 All Organisms are made of Cells and are organized

8 Facts About Cells Cells are the smallest living unit of an organism All cells contain living material called cytoplasm All cells are surrounded by a cell membrane that controls what enters & leaves the cell

9 More Cell Facts Cells are complex & highly organized Cells have parts called organelles that do different jobs e.g. Chloroplasts in plants make sugars e.g. Chloroplasts in plants make sugars

10 More Cell Facts The simplest cells are called Prokaryotes These cells DO NOT have a nucleus or membrane-bound organelles Bacteria are examples

11 More Cell Facts More complex cells are called Eukaryotes These cells DO have a nucleus and membrane- bound organelles Plants, animals, protists, & fungi are examples

12 Organisms are Grouped by their Number of Cells Unicellular Organisms Unicellular Organisms –Living Organism Made Up Of One Cell Multicellular Organisms Multicellular Organisms –Living Organism Made Up Of Many, Specialized Cells

13 Levels of organization AtomsMoleculesOrganellesCellsTissuesOrgansSystemOrganism

14 Organisms Reproduce to Pass on their Genetic Traits

15 Two Types of Reproduction Sexual Reproduction Involves 2 parents Egg fertilized by sperm to make a ZYGOTE Offspring DIFFERENT from parents

16 Two Types of Reproduction Asexual Reproduction Involves a single organism or cell Cell divides Offspring IDENTICAL to parent

17 Genetic Code DNA (deoxyribose nucleic acid) carries the genetic code for all organisms All organisms contain DNA DNA codes for the proteins that make up cells & do all the work

18 Organisms Grow & Develop

19 Growth & Development Organisms grow by producing MORE CELLS & by cell ENLARGEMENT Organisms develop as they mature into an adult organism

20 Metabolism Sum of all the chemical reactions in an organism All require energy Sunlight is the ultimate energy for life on Earth Photosynthesis

21 Metabolism Cellular Respiration –Cells releasing the chemical energy stored in foods 6O 2 + C 6 H 12 O 6 6CO 2 + 6H 2 O

22 Organisms Respond to Stimuli Organisms Respond to stimuli (Temperature, Water, Food Supplies, etc.) In Order To Survive & Reproduce

23 Homeostasis Keeping The Internal Environment (Homeostasis) Of The Cell or Organism Within The Ranges Required For Life Stable internal conditions of pH, temperature, water balance, etc. Organisms must have a way of REGULATING themselves in order to maintain a stable internal environment.

24 Living Things Evolve Groups Of Organisms (Not Individuals) Change Over Time In Order To Survive Within Changing Environments. Fossil records show changes in groups of organisms DNA and MUTATIONS are important in evolution.

Major Themes in Biology Unity and Diversity - even though life is so diverse, it is characterized by the features that all living things share. - even though life is so diverse, it is characterized by the features that all living things share. 25

26 Three Domains of Life Eukarya – largest domain. Archea – live in extreme environments. Bacteria – ALL COME A FROM A COMMON ANCESTOR.

Major Themes in Biology Interdependence of Organisms Ecology – studies how living and non- living things (environment). Ecology – studies how living and non- living things (environment). Ecosystems – communities of living species and their physical environments Ecosystems – communities of living species and their physical environments 27

Major Themes in Biology Evolution of Life Individual organisms change during their lifetime, but their basic genetic plan does not. Natural selection – organisms with favorable traits will survive to pass those traits on to their offspring. They are better able to survive than those lacking the traits. Traits come from genes and DNA. 28