form + function pt 1 (fusiform -> conformers)

how is a fusiform body shape related to evolutionary convergence?

fusiform means shaped like a torpedo or fish

this is related to evolutionary convergence because the environment that fish are in force their evolution to converge on a similar trait—their body—to help them swim better

what restricts exchange of materials in cells?

surface-to-volume ratio

→ small cells have a LARGE s/v ratio

→ large cells have a small s/v ratio

what body plan is easier for material exchange?

sac-like body plan

→ like cnidarians

how do animals with a large s/v ratio exchange materials with their environment?

they have complex systems to increase the surface area of that region

→ to help them transport materials across their membranes

what are the benefits of having a complex body plan (i.e. having organ systems with complex structures)?

protection (skin)

large muscles can enable rapid + precise movement

digestive organs break down food more easily + control the release of stored energy

*the organism can control the solute composition (i.e. homeostasis !!)

bioenergetics

flow of energy through an animal

how do bioenergetics limit behavior, growth, reproduction, and nutritional needs?

bioenergetics is energy. energy levels affect the traits above

→ i.e. if you are low on energy + hungry, it may affect your behavior

metabolic rate

sum of all energy requiring biochemical reactions occurring in a given period

how can metabolic rate be determined? what things can clue you in?

rate of heat loss

oxygen consumption or carbon dioxide release

rate of food consumption + energy content of food

there is an inverse relationship between ________ ____ and ____

metabolic rate + size

when an animal is small, its metabolic rate goes ____. when an animal is large, its metabolic rate goes ____.

up

down

what are 2 bioenergetic strategies?

1) endothermic

2) exothermic

endothermic vs exothermic

body heat generated from metabolism

vs

heat gained from external sources

endothermic is a _____ energy strategy. what does it allow? what animals does it include?

high

→ allows activity over a broad range of environmental temperatures

this includes birds and mammals

exothermic is a ____ energy strategy. what does it limit? what animals does it include?

low

→ limits the activity over varying environmental temperatures because animals are bound to a heat source

this includes invertebrates, fish, amphibians, and reptiles

basal metabolic rate

minimum rate of metabolic reactions to maintain basic life support functions (like cell maintenance, breathing, and heartbeat)

→ this must be measured on a non-growing endotherm at rest, with an empty stomach, and no stress

standard metabolic rate

minimum metabolic rate of an ectotherm at a specific temperature, resting, fasting, and non-stressed

what is the difference between basal metabolic rate and standard metabolic rate?

one refers to endotherms and the other refers to ectotherms

maximum metabolic rate

atp needed to sustain the highest metabolic rate (usually a burst of energy)

→ the atp is depleted immediately, meaning that the burst of energy cannot be sustained for more than a few seconds

endotherms can sustain a higher metabolic rate for longer compared to ectotherms. why?

they have a higher rate of respiration (more oxygen = more atp)

→ other factors that contribute to this are age, sex, body, environmental temperatures, quality + quantity of food, activity level, oxygen availability, and hormonal balance

what is NOT a factor that contributes to the difference in metabolic rate between endotherms and ectotherms?

size !!

where does the majority of food go once digested?

right to making atp

→ (most organisms spend little energy on growth and reproduction)

smaller animals have a big energy expenditure where as larger animals have a smaller energy expenditure. why?

small animals lose a lot of heat because they have less layers of fat in between their core and their skin so they need to thermoregulate more frequently

larger animals maintain heat easily because they have more layers of fat in between their core and their skin so they don’t need to thermoregulate as frequently

why do ectotherms use the least amount of energy expenditure?

the sun warms them up !! they don’t need to spend energy on something that the sun does for them. essentially, the sun thermoregulates them

what pH is needed to maintain homeostasis?

7.2-7.4

how do regulators cope with external changes?

they use internal control to moderate internal changes when an external fluctuation is occurring (like regulating temperature and solute concentration)

how do conformers cope with external changes?

they allow their internal environment to vary with external changes (like conforming to changes in temperature and solute concentration)

are there organisms that are regulators or conformers?

no

→ no organisms are perfect regulators or conformers