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!)