Physiology 3: Body sizing and scaling Flashcards
Define allometry
Body parts grow at diff rates
Define isometry
Body parts grow at same rate
What is size important for?
Metabolism
Homeostasis
Growth
Reproduction
Larger animals have a _____ SA:V
smaller
Larger animals tend to:
Move ____ ____
_____ digestion rates
_____ respiration rates
Lose heat to the environ ___ quickly
Lose water to the environ ___quickly
more slowly
Slower
Slower
less
less
Define ontogenetic allometry
Body proportions change with development e.g baby’s head is much larger in proportion to adults
Define isometric scaling
Body proportions stay the same with development, quite unusual e.g froglets to frogs
Define static allometry
Body proportions differ between individuals of the same age and sex within a species. Often seen in sexually selected traits
Define evolutionary allometry
Body proportions between individuals of different species
Describe the equation used to describe allometric relationships
y = ax^b
y = size of body part
X = measure of whole body size
a = an initial growth index (size of y when x = 1)
b = scaling exponent. Proportional change in y per unit x
On an allometric relationship graph, what does it mean if b = 0, and what will the line look like?
There’s no relationship between size of body part and body size
= line is flat
On an allometric relationship graph, what does it mean if b = 1, and what will the line look like?
isometry
= positive straight line
On an allometric relationship graph, what does it mean if b = <1, and what will the line look like?
is b is less than 1 means negative allometry
= non linear curve (x increases at a greater rate than y)
On an allometric relationship graph, what does it mean if b = >1, and what will the line look like?
if b is greater than 1 means positive allometry
= non linear curve (y increases at greater rate than x)
On an allometric relationship graph, what is on the x and y axis?
x = body size
y = allometric trait (e.g body part, physiological trait)
