Unit 1: Adaptations to Environmental Conditions Flashcards
[–] and [–] are important concepts for understanding adaptation
homeostasis and phenotypic plasticity
Homeostasis
maintaining an internal environment within certain parameters (body temp, blood glucose…)
Phenotypic Plasticity
phenotype expressed changes with conditions
Most living cells prefere a [–] range of pH
narrow
protein shape is sensitive to
[H+] or pH
cellular mechanisms are [–]
temperature sensitive
how do skunk cabbage plants grow in the winter?
they use the inefficiency of energy transfer in mitochondria to generate enough heat for growth in wintery conditions
plant growth potential depends on
sunlight
water
availability of nutrients in the soil
What are the horizons of soil?
O = dead organic litter (you will see this layer)
A = soil + decomposing organic material (“topsoil”)
E = soil without minerals (“subsoil”)
topsoil
- soil combined with decomposed organic material
- provides minerals
- determines how well a plant can grow
The surface area of soil particles can determine
how much water the soil can hold
why does clay carry a lot of water
it has a charge and water is attracted to charged particles
saturated soil
increase of water in the soil
too much water in the soil
field capacity
how much water the soil can hold
wilting point
too little water is held in the soil
C3 plants store energy as
sugars through reactions in the mesophyll cells in their leaves
where do plants exchange gases
the stoma
mesophyll pathway
- CO2 enters calvin cycle
- CO2 + RuBP is converted to G3P
- G3P exits cycle to become others sugars/can accumulate to become glucose or it is converted to RuBP (Rubisco)
photosynthetic equation
6CO2 + 6H2O -> C6H12O6 + 6O2
carbon dioxide + water -> glucose + oxygen
CAM adaptations
- change timing of photosynthesis
- Day = open stoma
- Night = close stoma -> process CO2
- found in terestrial plants
WHEN
C4 adaptations
- take CO2 and store under hot + dry conditions as C4 mediary
- grabs CO2 and moves it deep inside leave
- found in terestrial plants
- more common in this latitude (as in PA)
WHERE
Other adaptations in plants include changes in
morphology to defelct radiation or dissipate heat
Animals use [–] to maintain optimal oxygen saturation and core body temperature
countercurrent exchange
concurrent flow maximizes exchange at
50%
countercurrent flow exchange is
- much higher compared to concurrent
- water is running past blood that is less saturatied to maximize exhange
if body temp is < 37 degrees C
- body organs increase metabolism or increase shivering
- body temperature rises
- more energy turnover
if body temperature > 37 degrees C
- sweating and panting begins
- body temperature falls
- reduces heat
moisture harvesting lizards collect water on the body and transfer it to the mouth by
- the spikes allow water to collect and roll down to the head
- they then tilt their head back to drink the water
convergent evolution
different species use same adaptation to a common problem
thermal dormancy can occur under [–] temperatures
low or high temperatures
Phenotypic trade-offs
small volume = greater heat loss = increased surface area
larger volume = less heat loss = decreased surface area
Torpor
shut down body at colder temperatures to save energy
Aestivation
hibernation during the summer
hibernation
hibernation during the winter
