What is biology?

1. What is biology? • The study of living things (organisms) • Organism – any living thing • All living things share certain characteristics

2. Characteristics of Living Things1. Made of 1 or more cells • Unicellular (one cell) - ex. Bacteria • Multicellular (many cells) - ex. Animals, plants, fungi, protists

3. 2. Need energy to survive • Autotrophs - get energy from sun • (make glucose by a process called photosynthesis) • Convert glucose into ATP (cellular respiration)

4. Heterotrophs - get energy by consuming nutrients from their environment (take glucose and make ATP by a process called cellular respiration)

5. 3. Respond to stimuli in their environment • Stimuli - factors in the environment that living things react to (ex. Light, temperature, sound, etc.)

6. 4. All living things reproduce • Sexual - two sex cells required (sperm and egg) (meiosis –cell division to make an egg or sperm) • Asexual - only one parent cell is needed

7. 5. Grow and Develop • Each cell divides to make new cells (cell division) – results in growth (mitosis) • To progress from earlier to later stages of a life cycle:----Caterpillars develop into butterflies.

8. 6. Maintain homeostasis • Homeostasis – a relatively stable internal environment (within a certain range) “Balance” - (ex. Human body temperature (approximately 98.6 degrees F))

9. 7. Adapt and evolve over time • Evolution - gradual change in a populationof organisms over time • Individuals DO NOT evolve

10. 8. Have a universal genetic code • All living things have DNA • DNA passes on genetic information from one generation to the next • DNA = Deoxyribonucleic Acid

11. Which of the life characteristics is the one that only living things do/make? ATP (remember our challenge of what is living?) – a molecule of useable Energy (what our cells use!)