Biology Honors Chapter 5
What is a major difference between filtrate in the nephron and urine leaving the bladder?
The filtrate contains amino acids and vitamins, but urine does not because amino acids, some vitamins, and other nutrients are reclaimed as the filtrate is refined
Which of the following statements about fish gills is true?
They have a large surface area
The concentration of solutes in a red blood cell is about 2%. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions?
a hypertonic sucrose solution because water moves by osmosis from the hypotonic environment, the cell interior, to the hypertonic environment
The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of
active transport because the sodium-potassium pump moves ions across the plasma membrane against their concentration gradients. This requires energy and is an example of active transport
Which of the following is a difference between active transport and facilitated diffusion?
active transport requires the expenditure of cellular energy, and facilitated diffusion does not because active transport can move substances against the concentration gradient, but it requires energy, usually in the form of ATP
A waste product of respiration is
carbon dioxide
Fluidity of an animal cell plasma membrane is enhanced by __________.
cholesterol molecules because at low temperatures, cholesterol hinders solidification of the membrane because it prevents the close packing of phospholipids
Facilitated diffusion is
diffusion occurring via a transport protein
Which of the following statements regarding diffusion is false?
diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated
Phagocytosis is to eating as pinocytosis is to
drinking
The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of
endocytosis because in endocytosis, the plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell
Which of the following is one way that land animals tend to lose water to their environment?
evaporation because water evaporates from moist surfaces of the body
A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of
facilitated diffusion because in facilitated diffusion, molecules use a transport protein to move across the plasma membrane. There is a net movement of molecules down the concentration gradient -- that is, there is a net movement of molecules from where they are more concentrated to where they are less concentrated
The first step in the formation of urine is the
formation of filtrate that enters Bowman's capsule
Identify Structure A.
glycoprotein which is composed of both a carbohydrate and a protein
The cholesterol associated with animal cell membranes...
helps to keep phospholipids from being too close to one another
A plant cell placed in a(n) _____________ solution will lose water and plasmolyze.
hypertonic
There is a net diffusion of water out of an animal cell when it is placed in a(n) _____________ solution.
hypertonic
An animal cell placed in a(n) ___________ solution will gain water, swell, and possibly burst.
hypotonic
The ideal osmotic environment for a plant cell is a(n) ___________ environment.
hypotonic
Endocytosis moves materials _____ a cell via _____.
into ... membranous vesicles because the prefix "end-" means "inward"
Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment
is hypotonic to the protozoan
A plant cell surrounded by a(n) _________ solution will be flaccid (limp).
isotonic
The ideal osmotic environment for an animal cell is a(n) _____________ environment.
isotonic
What is hydrophobic like the interior of the plasma membrane?
lipid soluble molecules
In active transport,
molecules move across the plasma membrane against their concentration gradient because molecules move against their concentration gradient in active transport
In humans, incoming air is filtered, warmed, and humidified in the _____.
nasal cavity because the nasal cavity is a large air-filled cavity. Because of the large surface area, the air is warmed or cooled as it passes through; it is also humidified. Particulate matter is removed by the nasal hairs
What is the functional unit of the kidney?
nephron
Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of
passive transport
The process of a white blood cell is engulfing a bacterium is
phagocytosis
A white blood cell engulfing a bacterium is an example of _____.
phagocytosis because this occurs when a cell engulfs a large particle
The ________ is a passageway shared by both food and air.
pharynx
You know that this process is _____ because _____.
pinocytosis ... the cell is engulfing extracellular fluid because pinocytosis is "cell drinking"
Which of the following is a function of the human kidney?
processing of blood to form filtrate material, from which metabolic wastes are discarded because the kidneys function to adjust the composition of the body fluids and rid the body of metabolic waste materials
When placed in a hypotonic environment, where the solute concentration is below that of the cell, a houseplant will _____.
remain standing upright because the water balance in plants is remarkably different. In an isotonic solution plant cells will look flaccid (limp), and in a hypotonic environment they will be turgid (firm). The cell wall allows the plant cell to balance the osmotic pressures inside the cell
In earthworms, gas exchange occurs in the _________.
skin because the entire outer skin of earthworms is the respiration surface
The lipids in a cell membrane are arranged _________.
so that the non polar parts of two lipids point toward each other because a phospholipid bilayer can exist as a stable boundary between aqueous compartments because the molecular arrangement shelters the hydrophobic tails of the phospholipid from water while exposing the hydrophilic heads of water
Structure A is a ________.
solute because a solute is crossing the plasma membrane
Osmosis can be defined as
the diffusion of water
Identify Structure D.
the phospholipid bilayer of membrane that can be recognized by the presence of a head and two tails
Plasma membranes are selectively permeable. This means that...
the plasma membrane allows some substances to enter or leave a cell more easily than others
In order for gas exchange to occur, a respiratory surface must be _____.
thin and moist because carbon dioxide and oxygen must be dissolved in water to diffuse through the thin cells of a respiratory surface
Water crosses the plasma membrane
through facilitated diffusion or diffusion because water can cross the plasma membrane through the process of facilitated diffusion. However, water molecules can also cross the lipid bilayer directly
What is the function of Structure E (cholesterol)?
to stabilize the phospholipids in the plasma membrane
A series of air tubes that branches throughout the body describes which gas exchanges system?
tracheae because a tracheal system has its respiratory surfaces at the tips of tiny branching tubes inside the body
Structure B is a ________.
transport protein because the transport protein facilitates the movement of solute across the plasma membrane
Structure A is a(n) _______.
transport protein that allows solute molecules to enter the cell
Through which of the following structures does urine leave the bladder?
urethra
Exocytosis is
when a membranous vesicle is fusing with the plasma membrane and releasing its contents into the extracellular fluid
Phagocytosis is
when the process of engulfing large particles occurs