Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Boreal Ecology > Lecture 7 - Environmental Adaptations > Flashcards

Lecture 7 - Environmental Adaptations Flashcards

1
Q

what must plants and animals deal with in the boreal?

A

snow
wind
drought
lack of nutrients in soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what happens to plant tissues when water freezes?

A

water expands in the cells and destroys living tissues

sharp ice crystals can damage and kill cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

in what 2 ways does frozen water injure cells?

A
  1. rupturing cell membranes

2. altering permeability of membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what 2 methods do boreal plants escape frost damage?

A
  1. extra-cellular freezing

2. supercooling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

briefly describe extracellular freezing

A

antifreeze accumulates inside cell walls allowing cells to prevent freezing.
plants encourage ice formation in between cells and prevent them in cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

briefly describe supercooling

A

lowing temp of liquid or gas below its potential freezing point w/o becoming a solid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how do cold temps affect animals?

A

food scarcity
metabolism is disrupted
freezing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are 3 broad methods of staying able 0C

A

migration
stay warm
dormancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are 2 broad methods of dropping below 0C

A

Freeze avoidance

Freeze tolerance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does the choice of habitat reflect the difference strategies of coping with extreme temperatures?

A

above snow = accept cold temperatures and manage being cold

@ freezing zone = freeze tolerance (frogs)

below frost line = freeze avoidance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where is the best play to go for aquatic animals?

A

deeper bc fresh water is most dense at 4C so it sinks (warmer at bottom)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

why do fish dive deep in salt water?

A

avoid ice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what subnivean snow zone do arctic animals inhabit?

ex?

A

pukak

lemmings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what adaptation do greenland collared lemmings have to avoid freezing?

A

grow long wide claws in winter for digging snow since there are larger crystals in the pukak layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

acclimation vs adaptation

A

acclimation: readily and reversible modification caused by exposure to the environment (not inherited)
adaptation: accumulation of genteel changes to increase survival/reproduction. not readily reversible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

define homeotherm?

A

maintain a constant body temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

define endotherm

A

generates own body heat using own energy to maintain temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

define poikilotherm

ex?

A

animals with a variable body temp

moths/butterflies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

example of a poikilothermic endotherm

A

hibernating animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

define ectotherm

A

generally do not produce enough heat to maintain a constant body temp. Rely on external sources of heat.
MAY have constant Tb depending on behaviour and environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

example of a homeothermic ectotherm

A

several antarctic fish

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how do bee hives stay warm in winter?

A

bumblebees shiver to produce heat via muscle contraction. communal effort used to heat the colony and keep the queen warm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

list the general ways to reduce heat loss

A 
get big (bergman's rule)
get round (allen's rule)
adjust MBR
prevent heat loss (insulate, lower conductive HL, restrict evaporative HL)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

bergmann’s rule

A

animals of larger size found in colder envr (poles)

decrease SA:V

25
Q

why doesn’t bergmann’s rule always hold true with arctic animals?

A

large body size means more food is required

advantages of being large outweigh the disadvantages

26
Q

allen’s rule

A

roundness is most effective for SA:M

27
Q

example of allen’s rule

A

arctic foxes ears, muzzle, legs, tail

~allows them to conserve heat

28
Q

what can heat loss through conduction be prevented?

A

increase insulation

increase fur/feather thickness

29
Q

how is caribou hair adapted to cold environments?

A

hair is hollow and filled with air pockets since it’s such a good insulator

also increase density and thickness of fur

30
Q

what environmental variables decrease insulation through fur?

example of how this is mitigated

A

water
-pb fur sheds water efficiently
wind
- muskoxen w/ very long fur that isn’t affected by high winds

31
Q

Glogers Rule

A

pigmentation declines towards to poles since black objects absorb AND radiate more heat

32
Q

briefly, why are arctic animals white?

A
  • reduce heat gain from sun during activity to cool down and prevent overheating
  • lack of melanin increases room for air cavities (insulator)
  • reflect light onto black skin of the animal (doesn’t reflect but scatters!)
33
Q

how do animals cope with limited food availability in winter?

A

use fat deposits

34
Q

2 methods of lowering conductive heat loss

A

insulate extremities

allow peripheral tissues to cool

35
Q

example of insulating extremities

A

underside of paw with fur in caribou, polar bears and arctic fox

36
Q

benefits of knobbly feet?

A

reduce contact (conductive heat loss) between feet and ground

37
Q

how does foot size related to latitude?

A

increases with latitude

-> better at walking through snow

38
Q

why are huskies feet maintained so cold?

what is responsible for this?

A

decreases gradient tf less heat loss

cutaneous vascular plexus

39
Q

how to reduce convective heat loss? (evaporative less)

A

reindeer - conchae

  • increase SA
  • divide air flow
  • thick mucosal layer
40
Q

explain the process of inhaling and exhaling over conchae

A

inhale = air pass over warm mucosa, saturated with water. Mucosa cooled and warm air to lungs

exhale = air passing over cool mucosa is warm and wet from lungs. water condenses and mucosa warmed. animal exhales cool “dry” air

41
Q

4 options to dealing with temp when living in cold climate

A
  1. migration
  2. habitat selection
  3. adjust lifecycle
  4. adjust body temp
42
Q

what coping strategies are used that include a reduced metabolism?

A

hibernation
diapause
freezing
anoxia

43
Q

what are the 2 supercooling chemical categories and what habitats are each used in?

A

antifreeze proteins = subnivean habitats

cryoprotectants = exposed habitats

44
Q

what do antifreeze proteins do? where are they found?

A

decrease the freezing point

in plasma

45
Q

what does glycerol (cryoprotectant) do? where is it produced from?

A

reduce the nucleation potential of seed crystals

produced from fat

46
Q

what is it called when ice crystals form?

A

seeding

47
Q

what does freezing cause in the body?

A

freezing of intracellular fluids
change structure of proteins and inhibit function of enzymes
cause sells to shrink

48
Q

examples of freeze tolerate species

A 
frogs
painted turtles
garter snakes
some lizards
many insects
49
Q

freeze tolerance is most commonly seen in what animals?

A

those that cannot avoid coming in contact with ice

50
Q

how can wood frogs freeze without dying?

A

ice forms extracellularly but their growth it prevented.
Ice nucleating proteins initiate, antifreeze proteins prevent growth. high level of polyols intracellularly to prevent ice

51
Q

define hypothermia

A

core temperature drops below that required for normal metabolism and body functions

52
Q

define torpor

A

entry of animal into hypothermia with behavioural inactivity

53
Q

define hibernation

A

sustained state of torpor, entry to and exit from which is governed by internal signals together with exclusively seasonal external cues

54
Q

examples of animals that hibernate

A

richardson’s ground squirrel
arctic ground squirrel
little brown bat

55
Q

what are the precursors to hibernation?

A

seasonal phenomenon
gain up to 40% body mass
need polyundsaturated fats
find hibernaculum

56
Q

what indicates timing of hibernation?

A

circannual and environmental cues

57
Q

during hibernation, what slows down?

A 
DNA/RNA synthesis
protein synthesis
fuel metabolism
ion pumping
ATM turn over decrease to <5% normal
58
Q

what mechanism is used for arousal in hibernation?

A

BAT

59
Q

function of BAT vs WF

A

heat production via non shivering thermogenesis

insulation, energy and storage

Boreal Ecology (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions