BIOL224 Final (All chapters from the Biology 224 class at
USask from Fall 2025) Questions With Complete Solutions
1 myofibril = Correct Answers many sarcomeres
3 Major Roles of Nervous systems Correct Answers 1.
Collects information from external or internal environment
using modified neurons.
2. Process and integrate information, evaluates based on past
experiences or genetics
3. Transmits information, coordinates/regulates effector
cells/organs.
Activity in Hypothalamus is dependent on: Correct Answers
Negative feedback. The thyroid interacts with our body to
interact with the body systems. It produces T3 and T4, the
hypothalamus tells the thyroid to produce those hormones which
causes it to activate.
All muscle is... Correct Answers Bioelectric (produces a
membrane action potential)
Are APs activated by EP? Correct Answers Yes.
Are contractile cells found in all animals? Correct Answers
Yes
Are glomerular capillaries very leaky? Correct Answers Yes
Are metabotropic and ionotropic receptors ligand-gated ion
channels? Correct Answers Yes
,Axon Correct Answers Nerve fiber
Bilateral symmetry Correct Answers Can be divided along a
vertical plane at the middle to create two identical halves.
Triploblastic
Bioelectricity Correct Answers It all happens at the membrane
- membrane potentials
Cells of the NS Correct Answers 1. Neurons - generate
bioelectric signals to transmit information to other cells
2. Glial cells - "support" cells, assist neuronal signaling and
produce cerebrospinal fluid. They also maintain the environment
around neurons.
Coelom Correct Answers Fluid-filled cavity between the
intestines and the body wall. Formed within the mesoderm of
the embryo.
Contraction is based on interaction between what? Correct
Answers Supporting filaments (actin) and a motor protein
(myosin)
Current Correct Answers Flow of electrical charge between
regions, opposites attract, like repels
Do ectotherms or endotherms generate excess metabolic heat to
thermoregulate? Correct Answers Endotherms
,Does the PNS increase heartrate? Correct Answers No, the
SNS does.
Does the SNS inhibit stomach activity? Correct Answers Yes,
PNS stimulates digestion and stomach activity.
Dueterosome cleavage Correct Answers Radial Cleavage, cells
fate is not decided when cells are created (how identical twins or
twins happen).
Ectoderm Correct Answers Becomes skin and nervous systems
Effector Correct Answers Can be a neuron, muscle cell or any
other cell
Electrical synapses: Correct Answers Gap junctions directly
connect cytoplasm of each cell. Ions flow between cells and
there is a rapid flow of currents. It cannot be modulated, it is
excitatory only. Gap junction can be found with more activity,
the basis for learning something.
Endoderm Correct Answers Becomes muscle and skeleton
tissues.
Extracellular Fluid always has... Correct Answers High Na+
and low K+
Feedforward Correct Answers Future needs are anticipated,
often involves learning and complex behaviours.
Gastrulation Correct Answers Begins at vegetal pole.
, Germ layers Correct Answers Ectoderm, mesoderm, endoderm
H zone is: Correct Answers Myosin only, bisected by M line
Homeostasis Correct Answers Regulation of the body's
internal environment
How are chemicals broken down in the digestive system?
Correct Answers - Bonds are broken by enzymatic hydrolysis
- These chemical reactions are driven by specific enzymes:
amylases, lipases, proteases, nucleases
How are muscles generally grouped? Correct Answers As
antagonistic pairs around joints
How could animals prevent respiration from being diffusion
limited? Correct Answers As animal grows bigger in size, so
does the diffusion area. There is a very steep increase with birds
and mammals. Birds & mammals are endothermic and maintain
a higher rate of metabolism which = a higher rate of oxygen
needed. Birds also fly which is an extremely energetically costly
process so they need to be very efficient and a have a rapid
supply of oxygen.
How do gills work? Correct Answers Water enters the fish
through its mouth and passes out through the gills, oxygen
diffuses from the water into the blood in the gills and carbon
dioxide diffuses from the blood into the water
USask from Fall 2025) Questions With Complete Solutions
1 myofibril = Correct Answers many sarcomeres
3 Major Roles of Nervous systems Correct Answers 1.
Collects information from external or internal environment
using modified neurons.
2. Process and integrate information, evaluates based on past
experiences or genetics
3. Transmits information, coordinates/regulates effector
cells/organs.
Activity in Hypothalamus is dependent on: Correct Answers
Negative feedback. The thyroid interacts with our body to
interact with the body systems. It produces T3 and T4, the
hypothalamus tells the thyroid to produce those hormones which
causes it to activate.
All muscle is... Correct Answers Bioelectric (produces a
membrane action potential)
Are APs activated by EP? Correct Answers Yes.
Are contractile cells found in all animals? Correct Answers
Yes
Are glomerular capillaries very leaky? Correct Answers Yes
Are metabotropic and ionotropic receptors ligand-gated ion
channels? Correct Answers Yes
,Axon Correct Answers Nerve fiber
Bilateral symmetry Correct Answers Can be divided along a
vertical plane at the middle to create two identical halves.
Triploblastic
Bioelectricity Correct Answers It all happens at the membrane
- membrane potentials
Cells of the NS Correct Answers 1. Neurons - generate
bioelectric signals to transmit information to other cells
2. Glial cells - "support" cells, assist neuronal signaling and
produce cerebrospinal fluid. They also maintain the environment
around neurons.
Coelom Correct Answers Fluid-filled cavity between the
intestines and the body wall. Formed within the mesoderm of
the embryo.
Contraction is based on interaction between what? Correct
Answers Supporting filaments (actin) and a motor protein
(myosin)
Current Correct Answers Flow of electrical charge between
regions, opposites attract, like repels
Do ectotherms or endotherms generate excess metabolic heat to
thermoregulate? Correct Answers Endotherms
,Does the PNS increase heartrate? Correct Answers No, the
SNS does.
Does the SNS inhibit stomach activity? Correct Answers Yes,
PNS stimulates digestion and stomach activity.
Dueterosome cleavage Correct Answers Radial Cleavage, cells
fate is not decided when cells are created (how identical twins or
twins happen).
Ectoderm Correct Answers Becomes skin and nervous systems
Effector Correct Answers Can be a neuron, muscle cell or any
other cell
Electrical synapses: Correct Answers Gap junctions directly
connect cytoplasm of each cell. Ions flow between cells and
there is a rapid flow of currents. It cannot be modulated, it is
excitatory only. Gap junction can be found with more activity,
the basis for learning something.
Endoderm Correct Answers Becomes muscle and skeleton
tissues.
Extracellular Fluid always has... Correct Answers High Na+
and low K+
Feedforward Correct Answers Future needs are anticipated,
often involves learning and complex behaviours.
Gastrulation Correct Answers Begins at vegetal pole.
, Germ layers Correct Answers Ectoderm, mesoderm, endoderm
H zone is: Correct Answers Myosin only, bisected by M line
Homeostasis Correct Answers Regulation of the body's
internal environment
How are chemicals broken down in the digestive system?
Correct Answers - Bonds are broken by enzymatic hydrolysis
- These chemical reactions are driven by specific enzymes:
amylases, lipases, proteases, nucleases
How are muscles generally grouped? Correct Answers As
antagonistic pairs around joints
How could animals prevent respiration from being diffusion
limited? Correct Answers As animal grows bigger in size, so
does the diffusion area. There is a very steep increase with birds
and mammals. Birds & mammals are endothermic and maintain
a higher rate of metabolism which = a higher rate of oxygen
needed. Birds also fly which is an extremely energetically costly
process so they need to be very efficient and a have a rapid
supply of oxygen.
How do gills work? Correct Answers Water enters the fish
through its mouth and passes out through the gills, oxygen
diffuses from the water into the blood in the gills and carbon
dioxide diffuses from the blood into the water
