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Studying life. What does it mean to be alive? How do Biologists study life?. Living. http://videos.howstuffworks.com/hsw/8490-understanding-cells-the-characteristics-of-life-video.htm. To be alive you must -. Reproduce. Genetic code. Grow, develop. Obtain and use energy.
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Studying life What does it mean to be alive? How do Biologists study life?
Living • http://videos.howstuffworks.com/hsw/8490-understanding-cells-the-characteristics-of-life-video.htm
To be alive you must - • Reproduce. • Genetic code. • Grow, develop. • Obtain and use energy. • Respond to the environment. • Maintain a stable internal environment. • Change over time.
Reproduction • Reproduction: to copy, to produce again… • Sexual reproduction: two cells from two organisms unite to produce one for one new organism. (two parents) • Asexual reproduction: a cell from a single organism divides to form the cell for a new organism. (one parent)
Genetic code • Offspring must arise from an organism with similar genetic material. • DNA or RNA (in rare cases proteins) • A brown eyed mother and a blue eyed father produce a hazel eyed child. The genes for eye color are different but they share common human DNA- they are all three human!
Grow, Develop • All living things grow during some part of the life span.
Obtain and Use Energy • Metabolism: burning organic fuel to produce energy for life processes. • All life gets its energy from the sun- some organisms collect sun energy directly (plants), some organisms eat organisms that collect sun energy (everything else).
Respond to the Environment • Living things respond to stimuli (signals) from the environment. • Plants respond to light by? • Humans respond to eating lots of candy by?
Maintain an Internal Env. • Homeostasis: process that living things use to maintain a stable internal environment. • What happens when you cannot maintain a stable internal env? • Fever! • Hypothermia! • Dehydration! • Etc
Change Over Time • All living things evolve.
Cells • Smallest unit of life-all living things are made up of cells. • Cell: collection of living material separated from the environment.