define life create a list of characteristics associated with life--what tells you that something is...
TRANSCRIPT
Define Life
Create a list of characteristics associated with life--what tells you that something is alive?
Brainstorm with your partner.
Write them in the space up top (not by the numbers, we’ll fill those in in a bit)
What is biology?
The study of living things
All living things share certain characteristics
Characteristics of Living Things
2. Composed of 1 or more cells
Unicellular (one cell)
- ex. Bacteria
Multicellular (many cells)
- ex. Animals, plants
3. Require energy to survive
Autotrophs - get energy from sun
Heterotrophs - get energy by consuming nutrients from their environment
4. All living things reproduce
Sexual - two sex cells required (sperm and egg)
Asexual - only one parent cell is needed
5. Grow and develop
Each cell divides to make new cells (cell division) – results in growth
Some cells become specialized and perform different jobs than others (differentiation)
6. Respond to stimuli in their environment
Stimuli - factors in the environment that living things react to
(ex. Light, temperature, sound, etc.)
7. Adapt to their environment and evolve over time
Evolution - gradual change in a population of organisms over time
Individuals DO NOT evolve
8. Maintain homeostasis
Homeostasis – a relatively stable internal environment (within a certain range)
- (ex. Human body temperature (approximately 98.6 degrees F))
9. Have DNA
All living things have DNA
DNA passes on genetic information from one generation to the next
Do you think there is life elsewhere in the universe?
Take a couple minutes to think about what you think and explain WHY you think that.
http://www.pbs.org/wgbh/nova/space/hunt-alien-earths.html
ASTROBIOLOGY
*study of the origin, evolution, distribution, and future of life in the universe
Studying ways to look for life on other planets or moons.
1. Temperature
Must be between -15 to 115 deg Celsius
5 to 239 deg F
2. Water
Planet must have liquid water
It helps with chemical reactions
3. Atmosphere
Atmospheres protect planets from UV rays, meteorites, etc.
They can also serve as a source for nutrients, i.e. Nitrogen
4. Energy
All life needs a source of energy
Sun – light energy -> plants ->animals
Chemical energy – from volcanoes
5. Nutrients
Nutrients are the raw materials organisms need to construct and maintain their bodies
Ex. Carbon, Nitrogen, minerals
Extra: Magnetic Field
Earth’s magnetic field protects us from ions & solar wind that would kill all living things