Capter 8

Question 1

What is Physiology?

Answer 1

The study of the functions of organisms and
their parts

Question 2

What is physiological ecology?

Answer 2

The study of how organisms function in their environment

Question 3

What is Ecophysiology?

Answer 3

Ecophysiology is an
integrative field that strives
to unite multiple
subdisciplines of biology to
solve ecological problems

• Ecophysiology: “Ecology
  provides the questions, and
  physiology provides the
  tools to determine the
  mechanisms.”

Question 4

Thermobiology

Answer 4

The physiological mechanisms and
behavioural choices that are used to achieve a favourable energy balance

Question 5

Metabolism

Answer 5

Heterotrophic organisms need other
organisms to fulfill energy and nutritional
requirements
* Metabolism: the
chemical processes
within living organisms
that maintain life

Question 6

Aerobic metabolism

Answer 6

oxygen is involved in
converting carbohydrates,
lipids, proteins to ATP in
mitochondria

Question 7

Anaerobic metabolism

Answer 7

lower efficiency production
of ATP without oxygen
* Measure metabolic rate as
oxygen consumption
(aerobic) or heat production
(anaerobic)

Question 8

Ectotherms

Answer 8

organisms
that rely on the external
environment as the
primary source of heat
* They have slower
metabolic rates
* They can survive long
periods with little food

Question 9

Endotherms

Answer 9

organisms that rely on their own
metabolism for warmth
* They have faster
metabolic rates, and can
remain active in cool
environments
* Retain heat by insulation
and circulatory system
* Use considerable energy
for thermoregulation
* Typically also homeotherm

Question 10

Homeotherms

Answer 10

Organisms that maintain constant body
temperature

Question 11

Heterotherms
(poikilotherms):

Answer 11

organisms that cannot
maintain a steady body
temperature
Heterotherms often bask
to maintain body
temperature

Question 12

Endothermy/homeothermy in insects

Answer 12

Sphynx moths can
raise their thorax
temperature within
minutes, by muscle
contraction

Question 13

Heat production

Answer 13

Three quarters of
metabolized energy is
released as heat
* Some mammals have
brown adipose tissue
(fat), which releases all
energy as heat without
producing ATP

Question 14

Insulation

Answer 14

Effective
thermoregulation
requires ability to
conserve heat: insulation
* Hair and feathers work by trapping stagnant air
* Fat is also a good
insulator (mostly in
aquatic organisms)

Question 15

Counter-current exchange

Answer 15

A counterflow mechanism that enables fluids at different temperatures flowing in channels in opposite directions to exchange their heat content without mixing.

Question 16

Responce to cold

Answer 16

Rapid muscle
contractions (shivering)
produce heat
* Vasoconstriction reduces
heat loss
* Muscles contract to fluff
up feathers or fur when
cold (e.g. goose bumps)

Question 17

Respponses to heat

Answer 17

• Sweating and panting
  (evaporation cools)
• Vasodilation, especially
  in large-area organs
  such as ears
• Reduction of metabolic
  rate
• Seeking shade Warm animals may sweat,
  pant, vasodilate, become
  less active, and seek shade

Question 18

Torpor

Answer 18

• Relatively short-term condition of
  decreased activity
• bats do this
• heart rate temperature breathing all drop

Question 19

Hibernation

Answer 19

Long-term condition of decreased
activity in cold temperatures
(months or weeks long)
- heart
rate and
breathing slow
down and body
temperature
lowers to near
freezing

Question 20

Estivation

Answer 20

decreased activity in hot temperatures

Question 21

sleep

Answer 21

• no pysiological change

Question 22

Antifreeze

Answer 22

Antifreeze proteins:
substances which
reduce the freezing
point
* Polar marine fish can
live in waters <0°C
* Ice crystals would
normally destroy cells
* Dehydration to
concentrate the
cytoplasm and avoid
crystals

Question 23

Acclimatization

Answer 23

Acclimatization is the
physiological
adjustment of
organisms to abiotic
factors outside of their
normal zone
* Change in physiological
function smaller than
expected if organisms
have time to acclimate

Question 24

Gas exchange

Answer 24

Oxygen is required for
mitochondrial
respiration, and CO2
must be removed
* Oxygen transport
system is required,
except in very small
organisms (e.g. insects)
* Organs for gas
exchange: lungs and gills

Question 25

Gills and gas exchange

Answer 25

Gills: The gas exchange surfaces of aquatic animals * Water is more viscous than air; more energy is needed to move water over exchange surface * If water is cold, heat loss is considerable

Question 26

Gas exchange in air

Answer 26

* Lungs and tracheal systems are gas exchange surfaces in terrestrial animals * Some amphibians exchange gases through skin * Water loss due to evaporation is a problem in dry climates Aquatic mammals and reptiles also breathe air

Question 27

Respiratory pigments

Answer 27

Respiratory pigments (e.g. hemoglobin) allow more gas transport in body fluids * Blood plasma carries 3mL O2/L without hemoglobin; 200 mL O2/L with hemoglobin * Pigments are especially important for animals with high metabolic rates

Question 28

Physiological ecology of plants

Answer 28

Plants are autotrophs rooted in a fixed place, requiring: * Light * CO2 * Water * Mineral nutrients * Suitable temperature

Question 29

What is the formula for photosynthathis

Answer 29

Sunlight + 6CO2 + 6H2O → C6H12O6 + 6O2

Question 30

Stomata

Answer 30

Where carbon dioxide enters and oxygen and water vapour leaves

Question 31

Light reactions

Answer 31

* Absorption of sun’s energy produces ATP and NADPH (required to turn the carbon dioxide into glucose), and O2 is released from H2O * This reaction requires light

Question 32

Dark reaction

Answer 32

* ATP and NADPH is used to fix CO2 as sugars in the Calvin cycle * The first product is a molecule with 3 carbon atoms (3-phosphoglyceric acid), and the process is called C3 photosynthesis * Process is independent of light (but it can occur during daytime)

Question 33

Photorespiration

Answer 33

Photorespiration: Some plants can use O2 as a substrate for photosynthesis, instead of CO2 * This reaction is pronounced when CO2 is low, O2 is high, or temperatures are low * C4 plants evolved to avoid photorespiration because it is an energy-wasting reaction Corn, a warm climate plant, uses C4 path to avoid photorespiration

Question 34

C4 photosynthesis

Answer 34

C4 photosynthesis is an alternative chemical pathway, allowing plants to avoid photorespiration * C4 plants fix CO2 in mesophyll cells as a molecule with 4 carbon atoms (malate) then transport it to bundle sheath cells where O2 is absent * This also increases water efficiency - C4 plants fix CO2 in mesophyll cells as malate, transport it to bundle sheath, where O2 is absent - fixation of CO2 is done in different location than the Calvin cycle

Question 35

Co2 - h2o tradeoff

Answer 35

To acquire CO2 for photosynthesis, plants have to open their stomata * This leads to increased water loss * Under dry conditions, plants close their stomata * This is a problem for photosynthesis under dry conditions

Question 36

cam photosynthesis

Answer 36

Crassulacean Acid Metabolism (CAM) photosynthesis evolved to reduce loss of water * Stomata open at night when air humidity is high * CO2 is fixed as malate, stored in vacuoles * Stomata close during day * CO2 is released from the malate for Calvin cycle CAM plants are often succulents, such as cacti. - dry environments - fixation of CO2 is done at a different time than the Calvin cycle

Question 37

What equation describes pop size in an open pop

Answer 37

N(t+1) =Nt+ (B-D+(It-Et)

Question 38

Which one of the following statements about thermobiology is TRUE?A. Bears don't hibernate; they have extended sleep.B. Shivering allows organisms to warm up.C. Counter-current exchange allows animals to keep feet warm in cold environments.D. Antifreeze chemicals are important in the overwintering physiology of some frogs.E. All of the other statements are true.

Answer 38

e

Question 39

Which one of the following sequences about vocal learning behaviour is in the CORRECT ORDER? A. Crystallization > silent phase > sensory phase > sensorimotor phase B. Sensory phase > silent phase > sensorimotor phase > crystallization C. Sensory phase > sensorimotor phase D. Sensorimotor phase > sensory phase E. None of the sequences are in the correct order

Answer 39

b

Question 40

Which of the following statements about nutrient cycles is TRUE? A. Carbon is commonly found in Earth's atmosphere, and is not common within Earth's crust. B. Nitrogen is commonly found in Earth's atmosphere, and is not common within Earth's crust. C. Sulfur is commonly found in Earth's atmosphere, and is not common within Earth's crust. D. Phosphorus is commonly found in Earth's atmosphere, and is not common within Earth's crust E. All of the other statements are true

Answer 40

b

Question 41

What are autotrophs?

Answer 41

- plants - synthesis food using exsternal source of energy (sun) to create simple sugars from inorganic compounds

Question 42

What are heterotrophs?

Answer 42

- animals - survive by feeding on biomass

Question 43

Vasoconstriction

Answer 43

Vasoconstriction is accomplished by smooth muscle surrounding the arterioles that supply the skin. It slows the flow of blood to the surface, which reduces the heat lost to the environment

Question 44

Counter-Current Heat Exchange

Answer 44

The artery and vein supplying the limb are in proximity, so heat is exchanged between the two. As warm blood passes down the artery, heat is lost to the cooler venous blood returning from the distal end, thus reducing the amount of heat lost in the limb.

Question 45

Are CAM and C4 cycle the same?

Answer 45

C4 photosynthesis: fixation of CO2 is done in different location than the Calvin cycle CAM photosynthesis: fixation of CO2 is done at a different time than the Calvin cycle