bio 251 exam 1 WSU Ultimate Study Guide
(Updated 2025–2026)
Organs of the body are defined as - correct answer -a combination of two or more tissues that
make up a structure which performs a specific function
What contains most of the water found in the human body? - correct answer -intracellular fluid
What type of ductless gland secretes hormones into the bloodstream? - correct answer -
endocrine
smallest unit of life - correct answer -cells
Which tissue conducts signals primarily via electrical impulses? - correct answer -nervous tissue
Which ion has a greater concentration inside the cell than outside? - correct answer -
potassium, K+
What organelle synthesizes most of the ATP used by cells? - correct answer -mitochondria
the biggest component of the plasma membrane, generally consists of two hydrophobic fatty
acid "tails" and a hydrophilic "head" consisting of a phosphate group - correct answer -
phospholipid
Process of maintaining the interval environment in a state compatible for life - correct answer -
homeostasis
,How many cells are in the human body? - correct answer -100 trillion
what are the 4 types of primary tissue? - correct answer -epithelial, muscle, nerve, connective
What detects change in a regulated variable in negative feedback? - correct answer -sensors
Where do sensors send information to? - correct answer -the integrating center
Where do the integrating center relay messages to? - correct answer -the effector
What type of membrane protein spans the membrane, allowing part of it to face the cytosol
and another part to face the extracellular fluid? - correct answer -the transmembrane protein
What transport mechanism is passive? - correct answer -movement of sodium through ion
channels
What gradient determines the movement of ions across the membrane? - correct answer -
electrochemical gradient
What is primary active transport - correct answer -the process in which energy (ATP) is directly
used to move against a concentration gradient.
What is an example of primary active transport? - correct answer -Na+/K+ pump (sodium
potassium pump)
Molecules always move from... - correct answer -high to low concentration
, in facilitated diffusion, a molecule is moved... - correct answer -down its concentration gradient
with the assistance of a protein carrier molecule, and no energy is required.
What charge does intracellular fluid have? - correct answer -negative
Extracellular fluid has more... - correct answer -anions
What transport mechanism requires energy? - correct answer -primary and secondary
transport
In active transport, the affinity of the carrier protein for the molecule being transported is
greater on which side of the membrane? - correct answer -the side where the molecule is in a
lower concentration
Intracellular communication that occurs through the binding of a chemical receptor from one
cell to the other goes to a specfific... - correct answer -receptor
Direct communication between cells in contact with one another is accomplished through... -
correct answer -gap junctions
as the number of receptors on the cell membrane decreases, the response of the target cell
will... - correct answer -decrease
The affinity of a receptor for its messenger is a measure the... - correct answer -strength of
binding between messenger and receptor
Which type of chemical messenger, when releases, binds to receptors on the same cell that
released the chemical messenger? - correct answer -autocrine
(Updated 2025–2026)
Organs of the body are defined as - correct answer -a combination of two or more tissues that
make up a structure which performs a specific function
What contains most of the water found in the human body? - correct answer -intracellular fluid
What type of ductless gland secretes hormones into the bloodstream? - correct answer -
endocrine
smallest unit of life - correct answer -cells
Which tissue conducts signals primarily via electrical impulses? - correct answer -nervous tissue
Which ion has a greater concentration inside the cell than outside? - correct answer -
potassium, K+
What organelle synthesizes most of the ATP used by cells? - correct answer -mitochondria
the biggest component of the plasma membrane, generally consists of two hydrophobic fatty
acid "tails" and a hydrophilic "head" consisting of a phosphate group - correct answer -
phospholipid
Process of maintaining the interval environment in a state compatible for life - correct answer -
homeostasis
,How many cells are in the human body? - correct answer -100 trillion
what are the 4 types of primary tissue? - correct answer -epithelial, muscle, nerve, connective
What detects change in a regulated variable in negative feedback? - correct answer -sensors
Where do sensors send information to? - correct answer -the integrating center
Where do the integrating center relay messages to? - correct answer -the effector
What type of membrane protein spans the membrane, allowing part of it to face the cytosol
and another part to face the extracellular fluid? - correct answer -the transmembrane protein
What transport mechanism is passive? - correct answer -movement of sodium through ion
channels
What gradient determines the movement of ions across the membrane? - correct answer -
electrochemical gradient
What is primary active transport - correct answer -the process in which energy (ATP) is directly
used to move against a concentration gradient.
What is an example of primary active transport? - correct answer -Na+/K+ pump (sodium
potassium pump)
Molecules always move from... - correct answer -high to low concentration
, in facilitated diffusion, a molecule is moved... - correct answer -down its concentration gradient
with the assistance of a protein carrier molecule, and no energy is required.
What charge does intracellular fluid have? - correct answer -negative
Extracellular fluid has more... - correct answer -anions
What transport mechanism requires energy? - correct answer -primary and secondary
transport
In active transport, the affinity of the carrier protein for the molecule being transported is
greater on which side of the membrane? - correct answer -the side where the molecule is in a
lower concentration
Intracellular communication that occurs through the binding of a chemical receptor from one
cell to the other goes to a specfific... - correct answer -receptor
Direct communication between cells in contact with one another is accomplished through... -
correct answer -gap junctions
as the number of receptors on the cell membrane decreases, the response of the target cell
will... - correct answer -decrease
The affinity of a receptor for its messenger is a measure the... - correct answer -strength of
binding between messenger and receptor
Which type of chemical messenger, when releases, binds to receptors on the same cell that
released the chemical messenger? - correct answer -autocrine
