Characteristics of Life
Name one of the characteristics that make something alive
growth and development, metabolism, organization, response to stimuli, reproduction, evolution
What is the smallest unit of life?
A cell
What are the 3 parts of an atom?
Protons, neutrons, and electrons
What does hydrophobic mean?
"Water-fearing" - doesn't dissolve in water
Ice (sinks in/floats on) liquid water
floats on
Growth
What happened to the generations of finches on the Galapagos Islands that showed that they were evolving?
Their beak shapes changed over generations to match the type of food that was available to them - they were adapting to their environment
Which part of the atom makes bonds with other atoms?
Electrons
Why can polar molecules attract or repel one another?
Because they have partial positive and negative ends (like magnets)
What property of water causes it to bead up into droplets?
Cohesion
What is the difference between growth and development?
Growth = increase in size
Development = becoming more complex
How are unicellular and multicellular organisms different?
Unicellular = organism made of one cell; Multicellular = organism made of many cells
What is formed when atoms join by covalent bonds?
A molecule
What are hydrogen bonds?
bonds formed between polar molecules with partially positive hydrogen atoms
What's the difference between cohesion and adhesion
Cohesion = attraction between molecules of the same type (water-to-water); Adhesion = attraction between molecules of different types (water-to-other)
Give an example of a stimulus and a possible response
Example: Light (stimulus) → plant grows toward it (response)
Place these in order from smallest to largest: organ, tissue, cell, organ system
Cell → Tissue → Organ → Organ System
What's the difference between an ion and an isotope
Ion = charged atom (uneven protons/electrons); Isotope = different number of neutrons
How many hydrogen bonds can water make and why is this important?
Up to 4 - this gives water it's unique properties
Why is water called the "universal solvent"?
It dissolves more substances than any other liquid
Explain homeostasis and give one example
Keeping internal conditions stable (ex: sweating to cool body)
Is a single atom or molecule considered "alive"? Why or why not?
Explain the main difference between ionic and covalent bonds
Ionic = electrons transferred; Covalent = electrons shared
Why is water a polar molecule?
Water's electrons spend more time near the oxygen than the hydrogens
Water can absorb lots of heat without changing its temperature very much. Why is this important for life on Earth?
It keeps stable temperatures in oceans, lakes, rivers, etc. for the organisms that live in them.