What is biology?

The study of living things (organisms)Organism – any living thingAll living things share certain characteristics

Characteristics of Living Things

1. Made of 1 or more cellsUnicellular (one cell)

- ex. BacteriaMulticellular (many cells)

- ex. Animals, plants, fungi, protists

2. Need energy to survive

Autotrophs - get energy from sun(make glucose by a process called photosynthesis)Convert glucose into ATP (cellular respiration)

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

3. Respond to stimuli in their environment

Stimuli - factors in the environment that living things react to

(ex. Light, temperature, sound, etc.)

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

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.

6. Maintain homeostasis

Homeostasis – a relatively stable internal environment (within a certain range) “Balance”

- (ex. Human body temperature (approximately 98.6 degrees F))

7. Adapt and evolve over time

Evolution - gradual change in a population of organisms over time

Individuals DO NOT evolve

8. Have a universal genetic code

All living things have DNADNA passes on genetic information from one generation to the nextDNA = Deoxyribonucleic Acid

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!)