Ch. 4 Coping With Environmental Variation: Temperature And Water Flashcards
Cryonics -
Preservation of bodies by freezing, in hopes they can be brought back to life in the future
Few vertebrates can withstand freezing -
Freeze tolerance
Organisms have two options for coping with environmental variation:
Tolerance
Avoidance
Physiological ecology -
- study of interactions between organisms and their environment
- how these interactions influence their survival and persistence
The physical environment influences an organisms success in two ways:
- Affects availability of energy and resources and the ability to maintain metabolic functions, grow and reproduce
- extreme environmental conditions affect survival
Actual geographic distribution of a species also related to other actors, such as ___ and ___.
Disturbance and competition
A species ___ ___ is the range of conditions over which it occurs.
Climate envelope
Stress -
Environmental change results in decreased rates of important physiological processes, lowering potential for survival, growth, or reproduction
Hypoxia -
Not enough oxygen is delivered to your tissues
Acclimatization -
Short-term, reversible, process within a single individuals lifetime
An individual phenomena
Adaptation -
Long-term, population-level change to environmental stress over time via natural selection
A population phenomena
Ecotypes:
- populations with adaptations to unique environments
Acclimatization and adaptation require investments of energy and resources.
Represents possible ___ with other functions that can also affect survival and reproduction.
Trade offs
Some organisms can survive periods of extreme heat or cold by entering a state of ___, in which little or no metabolic activity occurs.
Dormancy
Examples of dormancy:
- hibernation
- daily torpor
- estivation
Energy exchange with environment can be by four processes -
Conduction
Convection
Evaporation
Radiation
Conduction -
Transfer of energy from warmer to cooler molecules
Example: snuggling -> heat will transfer from warmer person to cooler person
Convection -
Heat energy is carried by moving water or air
Example: if you’re in a pool and you are warmer than the water, you will heat up water around you. If your little sister comes by and swishes water and will move cold water onto you.
Evaporation -
Water absorbs heat as it changes state from liquid to gas
Example:
Radiation -
Radiating heat from warmer to cooler
Example: heat from fire will radiate to your hands
Losses of energy include emission of infrared radiation to environment, and through ___.
Evapotranspiration
What factors effect energy transfer in plants?
- solar radiation
- infrared radiation
- convective heat transfer
- conductive heat transfer
- heat transfer by evapotranspiration
Transpiration rates can be controlled by specialized guard cells surround a pose, called a ___.
Stomate
___ has been studied in the daisy family.
Pubescence
Reciprocal transplanting -
Plants of all species were grown in both locations
Boundary layer -
Zone of turbulent flow
Evaporative heat loss in animals includes:
- sweating in humans
- panting in dogs and other animals
- licking of body parts by some marsupials
Ectotherms -
Primarily regulate body temperature through energy exchange with external environment
Endotherms -
Rely primarily on internal heat generation
Ectotherms generally have higher tolerance for ___ ___ ___ than do endotherms.
Internal temperature variation
In exchanging heat with environment, the body’s ___ ___-to-___ ___ is an important factor.
Surface area-to-volume ratio
Larger surface area allows greater heat exchange/loss..
- adaptive in warm environments to dump excess heat
- longer appendages
- makes it harder to maintain internal temperature
Smaller surface area relative to volume decreases animals ability to gain or lose heat…
- shorter appendages
- adaptive in cold environments to decrease heat loss
Thermoneutral zone -
Constant resting metabolic rate over a range of environmental temperatures
Lower critical temperature -
- when heat loss is greater than metabolic production
- body temperature drops and metabolic heat generation increases
Example of acclimatization in willow ptarmigan
Thermoneutral zones and basal metabolic rates may vary with season
___ is often used to indicate a short-term dormancy but is used in this text as a general state of dormancy with decreased metabolism and controlled hypothermia.
Torpor
___ is a long-term winter dormancy.
Hibernation
___ is a summer dormancy in some desert animals.
Estivation
Small endotherms may regularly undergo daily ___ to minimize energy needed during cold nights.
Torpor
Long-term __ is only possible for animals that have enough food and can store enough energy reserves.
Torpor
___ is the medium in which all biochemical reactions necessary for life occur.
Water
Water flows along energy gradients:
Gravity
Pressure
Gravity on water
Water flows downhill
Associated energy of gravity is ___ ___.
Gravitational potential
Pressure on water
Water flows from area of higher pressure to lower pressure
Associated energy of pressure is ___ ___.
Pressure potential
Osmotic potential -
Water flows from a region of high concentration to a region of low concentration
Matric potential -
Energy associated with attractive forces on surfaces of soil particles or on surfaces of large molecules inside cells
Resistance -
Force that impedes water movement along an energy gradient
Osmotic adjustment -
I’m variable environments, cells must alter their osmotic potential to maintain water balance
Terrestrial plants take up water through their roots, and by beneficial fungi called ___.
Mycorrhizae
Example of trade-off
Plants lose water by transpiration when stomates are open for CO2 uptake
Xylem can be under high tension, which call pull air into the water column, called ___.
Cavitation
Aerenchyma -
Air channels in roots to alleviate oxygen stress
Pneumatophores -
Specialized vertical roots that allow air to enter roots
Hyperosmotic -
More saline than the animals cells
Hypoosmotic -
Less saline than the animals cells
Isoosmotic -
Have same solute concentration as animals cells
What organisms have the highest resistance to water loss?
Desert invertebrates
___-___ proteins outside cells serve as sites of slow, controlled ice formation.
Ice-nucleating
