Chapter 6: Plant Adaptations to the Environment Flashcards
Any plant that produces as its first step in photosynthesis the 3-carbon compound phosphoglyceric acid
C3 plant
A plant that has evolved a modified form of photosynthesis that increases water-use efficiency in warmer and drier environments
C4 plant and CAM plant
C4 photosynthetic pathway
Involves 2 distinct types of photosynthetic cells: the mesophyll cells and the bundle sheath cells
CO2 initially reacts with PEP to form 4-carbon compounds in the mesophyll cells
These compounds are then transported into the bundle sheath cells where they are converted into CO2 and undergo the C3 photosynthetic pathway (Calvin cycle)
CAM pathway (crassulacean acid metabolism)
Photosynthetic pathway (using same processes involved in C4 pathway) that separates the processes of carbon dioxide uptake and fixation when growing under arid conditions
It takes up gaseous carbon dioxide at night, when stomata are open, and converts it into simple sugars during the day, when stomata are closed
Difference between the rate of carbon uptake in photosynthesis and carbon loss in respiration
net photosynthesis
Depth of water or level of light at which photosynthesis and respiration balance each other
light compensation point
Able to grow and reproduce under low light conditions
shade-tolerant
Amount of light at which plants achieve the maximum rate of photosynthesis
light saturation point
The slowing or stopping of a plant process by light
photoinhibition
Loss of water vapor from a plant to the outside atmosphere
transpiration
Pores in the leaf or stem of a plant that allow gaseous exchange between the internal tissues and the atmosphere
stomata
Growing and reproducing best under high light conditions
Growing poorly and failing to reproduce under low light conditions
shade-intolerant
Dry, especially in soil
xeric
Moderately moist
mesic
A layer of still air close to or at the surface of an object
boundary layer
Essential nutrient needed in very small quantities by plants and animals
micronutrient
Essential nutrients plants and animals need in large amounts
macronutrient
An erect respiratory root that protrudes above waterlogged soils
Typical of bald cypress and mangroves
pneumatophore
Let’s talk about trade-off between growth rate and tolerance
“Plant adaptations to the abiotic environment represent a fundamental trade-off between phenotypic characteristics that enable high rates of photosynthesis and plant growth in high resource/energy environments and the ability to tolerate (survive, grow, and reproduce) under low resource/energy conditions.”
“The set of phenotypic characteristics that enhance a species’ carbon gain (photosynthesis and plant growth) under high resource/energy environments limit its tolerance (survival and growth) of low resource/energy conditions.”
“Conversely, the phenotypic characteristics that enable a species to survive, grow, and reproduce under low resource/energy conditions limit its ability to maximize growth rate in high resource/energy environments.”
Plants exhibit what 2 primary responses to CO2?
Increase in photosynthesis
Reduction in stomatal conductance
Let’s talk about plant response to increasing atmospheric carbon dioxide
Plants exhibit 2 primary responses to CO2:
- Increase in photosynthesis
- Reduction in stomatal conductance
The increase in photosynthesis occurs primarily in C3 plant species and is a response to reduced photorespiration.
The decrease in stomatal conductance functions to increase water-use efficiency.
Increased rates of photosynthesis result in an increase in growth rates.
