Chapter 7 Flashcards
What are 4 key processes of all animals)
1) acquiring and digesting food
2) absorbing oxygen
3) maintaining body temperature and water balance
4) adapting to systematic variation in light and temperature
What is scaling?
morphological and physiological features change as a function of body size in a predictable way
How does surface area to volume ratio differ with size?
smaller bodies have larger surface area relative to their volume
What is a drawback for a larger size?
the more surface area it required for oxygen and food absorption
What does metabolism require?
transfer of energy between organism and the environment
How do larger animals adapt to decreasing surface area? (3)
- by having a complex, wrinkled surface, it increases surface area so that oxygen can diffuse faster
- oxygen is transported through diffusion or active transport
- food canal/ digestive system to incorporate carbon and other nutrients
How do grazers, browsers, granivores, and frugivores all differ?
- grazers- leafy material
- browsers- woody
- granivores- seed
- frugivores- fruit
What do herbivores depend on?
specialized bacteria to digest cellulose
What makes a plant high quality, and why?
high in nitrogen, as more nitrogen means more growth
What parts of the plants do herbivores focus on, and how can they detec them?
- high nitrogen parts like new shoots
- detects through taste and odor
What kind of food do carnivores focus on, and why?
1) quantity is more important than quality
2) prey has resynthesized and store proteins and nutrients from plants into their tissues
What is the omnivorous food habit like?
food habits can vary with seasons, life stage, and size
What are conformers?
animals that induce internal changes that parallel external conditions
What are tradeoffs for conformers? (3)
- unable to maintain consistent internal conditions like body fluid salinity or oxygen levels
- involves changes in the biochemical systems to function under new conditions
- low energy but reduced growth and activity
What are regulators?
use a variety of biochemical, physiological, morphological, and behavior mechanisms to regulate internal environments over a broad range of external conditions
What are tradeoffs for regulators?
requires energetically expensive changes but can perform in a bigger range of conditions
What is the first change regulators often do?
behavior
What is homeostasis?
maintenance of a relatively constant internal environment in a varying external environment
What does homeostasis depend on?
negative feedback- when a system deviates from norm (set point), mechanism functions to restore system
What are the three parts of negative feedback?
- receptor- measures internal environment for change
- integrator- evaluates receptor info and determines whether action should be taken
- effector- functions to modify the internal environment
What is oxygen conformity, and what is it seen in?
oxygen consumption decreases in proportion to decreasing ambient oxygen concentrations, seen in small, marine organisms
How do small terrestrial organisms get oxygen?
diffusion into body
How do insects get oxygen?
spiracles
How do large terrestrial organisms get oxygen?
lungs to transfer
How do aquatic mammals get oxygen?
coming to the surface
How do most aquatic organisms get oxygen?
gills
How do aquatic insects get oxygen?
fill tracheal system with air at the surface, or carry a bubble of air under wings
How do terrestrial animals get water? (2)
1) drinking and eating
2) metabolic water through respiration
How do terrestrial animals lose water (3)?
- urine, feces
- evaporation from skin
- moist air the exhale
How do birds and reptiles absorb water? (2)
1) cloaca
2) salt glands
How do animals deal with arid environments? (7)
- move if seasonal
- estivation- dormancy during heat
- diapause- stage of arrested development in their life cycle
- lower temperature of air they breathe out
- remaining in borrows and emerging at night
- extract food from water
- produce concentrated urine and dry feces
How do freshwater organisms deal with water? (3)
There are hyperosmotic, so they must
- must absorb and retain salt in cells in gills
- produce watery urine
- amphibians can absorb salt through skin
How are marine animals related to the exchange of water?
Hypoosmotic
What are examples of isosmotic organisms?
jellyfish, anemones, molluscs
What are osmoconformers?
don’t actively adjust amount of water in tissues
What are osmoregulators?
maintains constant salt concentration in body, such as by secreting magnesium and calcium as a paste
What is a boundary layer?
thin layer of air or water around the surface of the skin
What is thermal conductivity, and what is it influenced by?
- ability to conduct or transmit heat
- influenced by insulation like muscle and fat
How do animals maintain core body temperatures
- change metabolic rate
- heat exchange through conduction (solid) or convection (radiation and evaporation)
What are poikilotherms?
animals with different ranges of body temperature
What are homeotherms, and what is it found in?
- body temperature is constant, maintains through endothermy
- only birds and mammals
What is endothermy?
process of maintaining body temperature internally through metabolic heat
What can homeotherms do to maintain body temperature>
can raise metabolic activity in excess of need to maintain body temperature
What is ectothermy ?
process of maintaining body temperatures through exchange of thermal energy with the environment
How does body temperature affect poikilotherms?
performance like movement, growth, development, and fecundity varies
What are traits of poikilotherms?
low metabolic rate and high ability to exchange heat between body and environment
When do poikilotherms perform anaerobic respiration?
during stress or pursuing prey
How do poikilotherms maintain preferred body temperature?
behavioral thermoregulation like basking or finding shade
What is operative environmental temperature?
body temperature that occurs when an organism is in an environment
Examples of poikilotherm acclimation
- metabolic reaction in cold temperatures increased to a level closer to that of warm-acclimated individuals
- aquatic pokilotherms can acclimate to changing temperatures, since it changes more slowly
How do homeotherms maintain temperature?
oxidizing glucose and other molecules during respiration, which converts some energy into heat
What is basal metabolic rate?
rate of oxygen consumption
What is the thermoneutral zone?
range of environmental temperatures within which metabolic rates are minimal
Why do homeotherms maintain higher body temperatures?
enzymes operates at higher temperatures
How do homeotherms regulate temperature during colder times? (3)
- insulation
- shivering
- burning brown fat in smaller animals
How does types of insulation differ?
- fur- balances insulation and mobility, changing form when it acclimates
- color- light to reflect heat
What are trade-offs for endotherms? (3)
- homeotherms can be active regardless of temperature variation
- great energy costs/ high metabolic rate
- the smaller the organism, the greater the heat loss > smaller organisms have higher metabolism
What are ectotherm tradeoffs? (5)
- environmental temperatures regulate poikilotherm activity
- energy intake can be used for growth
- requires fewer calories per body weight
- can survive longer with limited food and water
- has a max body size because surface area decreases with volume, and larger it is, less heat it can absorb
What are heterotherms?
species that can switch between being a homeotherm and a poikilotherm
How can some adult insects act as heterotherms?
when flying, they produce heat like homeotherm > need to be warm to fly, but not too warm (warming can be done by basking or shivering)
How can homeotherms act as heterotherms?
mice and hummingbirds entering torpor
What is hibernation?
hibernation- cessation of activity and controlled hypothermia. allowing small homeotherms to eliminate need for food
What is acidosis?
high CO2 level in blood and acidic blood when hibernating, which lowers threshold for shivering and metabolic rate
How do bears act as heterotherms?
Enter winter sleep (not hibernation) and recycles urea through the bloodstream to use as amino acids > maintains body temperature and metabolism
How can camels and gazelles deal with heat?
can store body heat during they day and release at night > reduce need for evaporative cooling and water loss
What is supercooling?
body temperature falls below freezing without freezing using solutes like glycerol (seen in fish, insects, and reptiles)
How can intertidal invertebrates deal with extreme cold?
concentrating solutes in unfrozen fluids
What is countercurrent heat exchange?
conserving heat in a cold environment and cooling vital parts under heat stress
How do porpoises exchange heat, in a cold and warm environment?
exchanging heat between arterial (coming from lungs) and venous (returning to lungs) blood
when in cold environment veins carries warm blood to the extremities and cools from the venous blood (prevents body heat from passing and warms flippers)
when in warm environment, venous blood returns cold through veins near the skin to cool
What is rete?
discrete vascular bundles of divided vessels in poikilotherms like tuna to warm muscles
How does rete control temperature?
countercurrent heat exchange occurs as blood flows in opposite directions
What is the fundamental factor for an organism?
Habitat
What is the fundamental constraint of an organisms distribution?
availability of essential resources and environmental conditions (pH, temperature, salinity)
3 requirements for a species to be successful in a location
- provide food
- cover from predators
- areas for successful reproduction
What does habitat reflect?
habitat is a reflection of adaptations for species processes
What is habitat selection?
process of selecting a specific location to inhabit, involving a hierarchical approach
What is an example of habitat selection?
birds first find a broad area,
> then look into physical structure of vegetation > then look into actual plant species (seeds and fruit)
