chapter five Flashcards
1
Q
cline
A
- a gradual change in some phenotypic characteristic from one population to the next
- visible
2
Q
how cline and race are different concepts
A
- cline is based on environmental factors while race is a social concept
3
Q
grandmothering
A
postmenopausal females caring for children
4
Q
grandmothering as a tool for adaptive success
A
- providing food and essential information about the world to various members of their social groups
5
Q
how the body adapts to heat
A
- vasodilation: the dilation (expansion) of blood vessels; moves more blood (and associated heat) away from the body’s core to surface
- sweating: mostly water; evaporation of it leads to cooling
6
Q
how the body adapts to heat stress
A
- bergmann’s rule
- allen’s rule
7
Q
bergmann’s rule
A
- states that heat adapted mammal populations will have smaller bodies than cold-adapted mammal populations
- small bodies have more surface area = promotes heat dissipation
8
Q
allen’s rule
A
- states that heat-adapted mammal populations will have long limbs
- increase the surface area in which heat can dissipate
9
Q
how the body adapts to cold
A
- vasoconstriction: constriction of blood vessels; reduces blood flow and heat loss from body’s core to skin
- shivering
- larger bodies and shorter limbs = promotes heat conservation
10
Q
how solar radiation affects skin colour
A
- measured by skin reflectance, uv radiation
- darkest skin (low skin reflectance) = highest levels of uv radiation, lightest skin (high skin reflectance) = lowest levels of uv radiation
- ongoing exppsure = melanocytes (produces melanin) increase the number and size of melanin= darkening/tanning
11
Q
how solar radiation affects vitamin D synthesis
A
- UV photons penetrate the skin and is absorbed by 7-dehydrocholestrol in the epidermis and dermis layers
- produces previtamin D that is eventually converted to active form of vitamin D
12
Q
how solar radiation affects folate production
A
- uv radiation breaks down folate which is essential for for making DNA and supporting cell growth
- can lead to lower folate levels, increasing birth defects and anemia
13
Q
wolff’s law
A
- the principle that bone is placed in the direction of functional demand (where needed)
- i.e. when a person lifts weights, the bones experience increased stress and become denser and stronger over time
- adaptation helps prevent fractures and can improve overall athletic performance
14
Q
what is bone composed of
A
- connective tisue
- cells (osteoblasts, osteoclasts, osteocytes)
- collagen and calcium phosphate
15
Q
osteoblasts
A
responsible for the remodelling of new bone tissue
16
Q
osteoclasts
A
chewing up what needs to be removed
17
Q
osteocytes
A
surrounded by calcified extracellular matrix
