Biology 100, Study Guide for Exam 1
UPDATED ACTUAL Exam Questions and
CORRECT Answers
What are the 5 characteristics of life? - CORRECT ANSWER - (1) Organization, (2)
energy use, (3) maintenance of internal constancy (homeostasis) (4) reproduction, growth, and
development, (5) evolution
What is an element? - CORRECT ANSWER - An element is a substance that is made
entirely from one type of atom.
What is an isotope? - CORRECT ANSWER - An atom of the same element that has the
same number of protons but a different number of neutrons
What is a polar covalent bond? - CORRECT ANSWER - A bond formed when atoms
share electrons unevenly
Know the 5 characteristics of water that are important to life - CORRECT ANSWER -
Water is cohesive (sticks to itself), water regulates temperature, water expands when it freezes,
universal solvent, and it participates in life's chemical reactions
What are the two chemical reactions that build up and break down organic molecules -
CORRECT ANSWER - Dehydration synthesis and hydrolysis
What is a lysosome? - CORRECT ANSWER - Small organelles filled with digestive
enzymes; one function is to break down lipids, carbohydrates, and proteins from food particles;
may also break down old cell parts
What is the cell membrane primarily made up of? - CORRECT ANSWER - The cell
membrane, the most external layer of all animal cells, is composed of two layers of lipid
molecules (the lipid bilayer). The lipid molecules each have a hydrophilic (water-loving, or
polar) end and a hydrophobic (water-hating, or nonpolar) end.
UPDATED ACTUAL Exam Questions and
CORRECT Answers
What are the 5 characteristics of life? - CORRECT ANSWER - (1) Organization, (2)
energy use, (3) maintenance of internal constancy (homeostasis) (4) reproduction, growth, and
development, (5) evolution
What is an element? - CORRECT ANSWER - An element is a substance that is made
entirely from one type of atom.
What is an isotope? - CORRECT ANSWER - An atom of the same element that has the
same number of protons but a different number of neutrons
What is a polar covalent bond? - CORRECT ANSWER - A bond formed when atoms
share electrons unevenly
Know the 5 characteristics of water that are important to life - CORRECT ANSWER -
Water is cohesive (sticks to itself), water regulates temperature, water expands when it freezes,
universal solvent, and it participates in life's chemical reactions
What are the two chemical reactions that build up and break down organic molecules -
CORRECT ANSWER - Dehydration synthesis and hydrolysis
What is a lysosome? - CORRECT ANSWER - Small organelles filled with digestive
enzymes; one function is to break down lipids, carbohydrates, and proteins from food particles;
may also break down old cell parts
What is the cell membrane primarily made up of? - CORRECT ANSWER - The cell
membrane, the most external layer of all animal cells, is composed of two layers of lipid
molecules (the lipid bilayer). The lipid molecules each have a hydrophilic (water-loving, or
polar) end and a hydrophobic (water-hating, or nonpolar) end.
