Science 2 Flashcards
How long ago did life on Earth evolve?
3.5 billion years ago
What does evolution mean for life on Earth?
It means all life on Earth is related and shares a common ancestor.
What is evolution fueled by?
Genetic mutations
True or false? Individuals themselves can evolve.
False
Organisms have the ability to __, __, and __ energy
capture, store, and transmit
How many chemical elements is Earth composed of?
23 of the 107 known chemical elements
What four chemical elements make up 99% of the mass of living organisms?
Carbon, hydrogen, oxygen, and nitrogen
What do scientists think protocells developed into?
Single-celled bacteria-like organisms
Where do scientists think life on Earth originated from?
Deep-sea hydrothermal vents
The basic unit of life is ___?
Cell
List the 4 main categories of macromolecules
Carbohydrates, lipids, proteins, nucleic acids
What are viruses most known for?
Causing diseases in humans; they can also infect and destroy bacteria and unicellular algae in the ocean in the process of reproduction
What do viruses span?
The living and nonliving
Are viruses living or nonliving?
Biologists are not in agreement that viruses are alive
In what shapes do bacteria come?
Spheres, spirals, rods, and rings
Where is decay bacteria common in and what does it do?
In detritus, breaks down waste products as well as dead organic matter and releases nutrients back into the environment
What does archaea look like and where was it first discovered?
They can be spherical, spiral, or rod-shaped; first discovered in extreme temperatures (e.g. hot sulfur springs)
What is seaweed and where does it thrive?
Multicellular algae; shallow, cold nutrient-rich temperature
How is it divided?
In colors: red, brown, green
How does it affect the economy?
It is widely used for products, ranging from foods to cosmetics
What are autotrophs?
Organisms that can nourish themselves from inorganic sources using photosynthesis or chemosynthesis.
What is taxonomy?
The study of biological classification.
What are the three classifications of organisms on Earth?
Bacteria, archaea, and eukarya.
What are algae?
Freshwater photosynthetic organisms
What is plankton?
Pelagic organisms that live suspended in seawater
Are plankton animals or plants?
They can be both
What are invertebrates
Animals without a backbone
What are vertebrates?
Animals with a backbone
How many multicellular animals are invertebrates?
More than 97 percent
