U7 Test Flashcards
Define organism
Any living thing that functions as an individual
What is a cell?
A microscopic membrane bound sack made of specilized structures that work together to keep the cell alive and the basic building blocks of life
Define metabolism
All life-supporting chemical reactions taking place inside cells and bodies that produce, convert, and release energy
What does it mean to grow?
To get bigger
What does it mean to develop?
To get more complex
What is a stimulus?
Any change that triggers a response
Define homeostasis
The power to maintain stable internal conditions even if external environments change
What does it mean to reproduce?
The process of sharing genetic info to make more of the same kind of organism
What does it mean to evolve?
When a breeding group of organisms changes and better adapts to their environment from one generation to the next due to random changes in DNA coding and natural selection
How long has prokaryotic life been on Earth?
3.7 BYA
How long has eukaryotic life been on Earth?
2.7 BYA
What is the Primordial Soup Theory?
The chemistry of life came together in warm, shallow pools on Earth’s surface
What is the Deep-Sea Vents Theory?
The chemistry of life came together near deep ocean, mineral-rich, hot water (hydrothermal) vents
What is the Panspermia Theory?
Life was delivered to Earth from space on meteorites and comets
Approximately how many eukaryotic species have been identified?
~1.2 million different species
What is the ratio of identified eukaryotic species to estimated eukaryotic species?
3:1
List the 10 key characteristics of life shared by all organisms
- Made of one or more cells
- Made of similar, carbon-based molecules (proteins, carbohydrates, lipids, and nucleic acids)
- Require water to survive
- Take in and use energy
- Grow and develop
- Detect and respond to stimuli
- Rely on homeostasis
- Reproduce
- Use DNA and RNA to carry inherited information
- Evolve
What are the 3 reasons why water is essential to all life?
- Water fills up cells providing physical support from the inside
- Water-based fluids help transport molecules and remove waste products
- Water is the medium in which life-sustaining chemical reactions occur
What is the approximate number of human cells in an average adult human?
15 trillion
What is the approximate number of bacterial cells in an average adult human?
38 trillion
