BIO 242 CORE EXAM 2026 TEST QUESTIONS AND
ANSWERS GRADED A+
✔✔are birds reptiles? - ✔✔yes birds are reptiles
✔✔key characteristics of birds that set them apart from other reptiles (2) - ✔✔-reduced
number of bones, bones are thin-walled and hollow so they are extermly light weight for
thier size.
-endotherms; can sustain energy year round.
✔✔homeostasis - ✔✔stability in the chical and physical conditions within an organisms
cells, tissues and organs
✔✔thermoregulation and how animals vary in this. - ✔✔the process by which animals
control their body temperature
animals vary in how they obtain heat and weather body temperature is held constant.
✔✔endotherm vs ectotherm - ✔✔endotherms internally generate heat to keep warm
ectotherms rely on heat obtained from the environment.
✔✔homeothem - ✔✔an animal that keeps its body temp constant
✔✔Poikilotherm - ✔✔an animal whose body temp rises/falls depending on
environmental conditions.
✔✔osmoregulation - ✔✔the process by which animals control the concentration of
water and solutes within thier bodies
✔✔osmotic stress - ✔✔occurs when concentration of dissolved substances in cell/tissue
is abnormal.
✔✔osmoregulation in sea water for fish - ✔✔-done by gills that must be in direct contact
with seawater.
solute concentration is higher outside the cells (sea water) than inside the cells
-water tents to flow our of gill tissue
✔✔how do marine body replace lost water and pump ions? - ✔✔drink large quantities of
sea water, actively pump ions out of bodies using membrane proteins in the gill tissue
✔✔osmoregulation in freshwater - ✔✔solute concentration in higher inside cells so
water flows into tissue via osmosis, excrete large amount of water in urine and do not
drink.
✔✔water loss in terrestrial animals - ✔✔urine and sweat
, ✔✔water balance in terrestrial insects - ✔✔exoskeleton covered in a layer of wax called
the cuticle, this minimizes water loss from the body surface.
✔✔how does gas exchange happen for terrestrial insects? - ✔✔gas exchange happens
in the tracheal system the connects with atmosphere at openings called spiracles.
muscle can open and close the spiracles to control water loss.
✔✔electrolyte balance in insects - ✔✔insects have blood-like fluid called hemolymph.
pre urine is filtered out from hemolymph and flows into hindgut to join digested food.
electrolytes and water can be reabsorbed from hindgut into hemolymph.
✔✔osmoregulation in terrestrial vertebrates - ✔✔water loss via evaporation from
surface of body and lungs
water and electrolyte lost via urine
replace water and electrolytes by eating and drinking.
✔✔5 steps of gas exchnage - ✔✔1. ventilation
2. diffusion
3.circulation
4. difussion
5. cellular repiration
✔✔How do many small animals exchange gases? - ✔✔obtain O2 and expel CO2 by
diffusion across the body surface.
✔✔how do gills work? - ✔✔fish open and close thier mouths to move water through
gills. water flows in one direction over fill filaments and blood flows the opposite way.
✔✔amphibian lungs - ✔✔simple sacs lined with blood vessels
✔✔mammal lungs - ✔✔divided into tiny sacs and alveoli. mammalian limbs have 40 x
more surface area for gas exchange.
✔✔fitness - ✔✔an organims ability to survive and produce viable, fertile offspring.
✔✔4 types of species interactions - ✔✔-commensalism
-consumption
-mutualism
-competition.
✔✔mutulaism (+/+) - ✔✔both individuals get fitness benefits from each other (is NOT
the same as symbiosis)
bees and flowers
ANSWERS GRADED A+
✔✔are birds reptiles? - ✔✔yes birds are reptiles
✔✔key characteristics of birds that set them apart from other reptiles (2) - ✔✔-reduced
number of bones, bones are thin-walled and hollow so they are extermly light weight for
thier size.
-endotherms; can sustain energy year round.
✔✔homeostasis - ✔✔stability in the chical and physical conditions within an organisms
cells, tissues and organs
✔✔thermoregulation and how animals vary in this. - ✔✔the process by which animals
control their body temperature
animals vary in how they obtain heat and weather body temperature is held constant.
✔✔endotherm vs ectotherm - ✔✔endotherms internally generate heat to keep warm
ectotherms rely on heat obtained from the environment.
✔✔homeothem - ✔✔an animal that keeps its body temp constant
✔✔Poikilotherm - ✔✔an animal whose body temp rises/falls depending on
environmental conditions.
✔✔osmoregulation - ✔✔the process by which animals control the concentration of
water and solutes within thier bodies
✔✔osmotic stress - ✔✔occurs when concentration of dissolved substances in cell/tissue
is abnormal.
✔✔osmoregulation in sea water for fish - ✔✔-done by gills that must be in direct contact
with seawater.
solute concentration is higher outside the cells (sea water) than inside the cells
-water tents to flow our of gill tissue
✔✔how do marine body replace lost water and pump ions? - ✔✔drink large quantities of
sea water, actively pump ions out of bodies using membrane proteins in the gill tissue
✔✔osmoregulation in freshwater - ✔✔solute concentration in higher inside cells so
water flows into tissue via osmosis, excrete large amount of water in urine and do not
drink.
✔✔water loss in terrestrial animals - ✔✔urine and sweat
, ✔✔water balance in terrestrial insects - ✔✔exoskeleton covered in a layer of wax called
the cuticle, this minimizes water loss from the body surface.
✔✔how does gas exchange happen for terrestrial insects? - ✔✔gas exchange happens
in the tracheal system the connects with atmosphere at openings called spiracles.
muscle can open and close the spiracles to control water loss.
✔✔electrolyte balance in insects - ✔✔insects have blood-like fluid called hemolymph.
pre urine is filtered out from hemolymph and flows into hindgut to join digested food.
electrolytes and water can be reabsorbed from hindgut into hemolymph.
✔✔osmoregulation in terrestrial vertebrates - ✔✔water loss via evaporation from
surface of body and lungs
water and electrolyte lost via urine
replace water and electrolytes by eating and drinking.
✔✔5 steps of gas exchnage - ✔✔1. ventilation
2. diffusion
3.circulation
4. difussion
5. cellular repiration
✔✔How do many small animals exchange gases? - ✔✔obtain O2 and expel CO2 by
diffusion across the body surface.
✔✔how do gills work? - ✔✔fish open and close thier mouths to move water through
gills. water flows in one direction over fill filaments and blood flows the opposite way.
✔✔amphibian lungs - ✔✔simple sacs lined with blood vessels
✔✔mammal lungs - ✔✔divided into tiny sacs and alveoli. mammalian limbs have 40 x
more surface area for gas exchange.
✔✔fitness - ✔✔an organims ability to survive and produce viable, fertile offspring.
✔✔4 types of species interactions - ✔✔-commensalism
-consumption
-mutualism
-competition.
✔✔mutulaism (+/+) - ✔✔both individuals get fitness benefits from each other (is NOT
the same as symbiosis)
bees and flowers
