Textbook - Chapter 6: Plant Adaptations Flashcards
Aerenchyma
Interconnected gas-filled chambers in the roots of aquatic plants
Bundle sheath cells
Cells surrounding small vascular bundles in the leaves of vascular plants
Boundary Layer
A layer of still air to or at the surface of an object
Carbon balance
Balance between uptake of CO2 in photosynthesis and its loss through the process of transpiration
CAM pathway (crassulacean acid metabolism)
Photosynthetic pathway that separates the processes of carbon dioxite 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.
C4 Photosynthetic pathway
Photosynthetic pathway involving two distinct types of photosynthetic cells: the mesophyll cells and th bundle sheath cells. CO2 intially reacts with PEP to form 4-carbon compounds in the mesophyll cells. These compounds are then transported into CO2 and undergo the C3 photosynthetic pathway (Calvin cycle)
C3 plant
Any plant that produces as its first step in photosynthesis the three-carbon compound phosphoglyceric acid.
Halophyte
Terrestrial plant adapted morphologically or physiologically to grow in salt-rich soil.
Light saturation point
Amount of light at which plants achieve the maximum rate of photosynthesis
Leaf area ratio (LAR)
Total area of leaves per total plant weight
Leaf weight ration (LWR)
The total weight of leaves expressed as a proportion of total plant weight
Light compensation point
Depth of water or level of light at which photosynthesis and respiration balance each other
Micronutrient
Essential nutrient needed in very small quantities by plants and animals
Mesophyll
Specialized tissue located between the epidermal layers of a leaf
Matric potential
Tendency of water to adhere to surfaces
Macronutrients
Essential nutrients plats and animals need in large amounts
Net photosynthesis
Difference between the rate of carbon uptake in photosynthesis and carbon loss in respiration
Net assimilation rate (NAR)
Assimilation of new plant tissue per unit leaf area per unit time
Osmotic potential
The attraction of water across a membrane. The more concentrated a solution, the lower is its osmotic potential
Pneumatophore
An erect respiratory root that protrudes above waterlogged soils; typical of bald cypress and mangroves
Photosynthesis
Use of light energy by plants to convert carbon dioxide and water into simple sugars
Photoinhibition
The slowing or stopping of a plant process by light
Pep carboxylase
The enzyme that catalyzes the fixation of CO2 into four-carbon acids, malate and aspartate
Rubisco
Enzyme in photosynthesis that catalyzes the initial transformation of CO2 into sugar
Relative growth rate
Weight gained during a specified period time
Specific leaf area
The area of leaf per gram of leaf weigth (cm2/g)
Shade tolerant
Able to grow and reproduce under low light conditions
Shade-intolerant
Growing and reproducing best under high light conditions; growing poorly and failing to reproduce under low light conditions
Stomata
Pores in the leaf of stem of a plant that allows gaseous exchange between the internal tissues and the atmosphere
Target of selection
The phenotypic trait that natural selection acts directly upon
Turgor pressure
The state in a plant cell in which the protoplast is exerting pressure on the cell wall due to intake of water by osmosis
Transpiration
Loss of water vapor from a plant to the outside atmosphere
Water-use efficiency
Ratio of net primary production to transpiration of water by a plant
