Term
| Plants are multicellular, _____________ organisms that have __________ with cellulose. |
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Definition
| photosynthetic; cell walls |
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Term
| Plants retain their ____________ within the tissues of the maternal parent where they develop into _____________. |
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Definition
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Term
| What is the key evolutionary innovation that enables plants to colonize land? |
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Definition
| The developing embryo of a plant is protected from desiccation. |
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Term
| Plants form a ______________ lineage (i.e., they are all descendants of a common ancestor that made the transition from an aquatic to a terrestrial environment). |
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Definition
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Term
| DNA sequence data indicate that the ancestors of plants belong to the _____________ lineage, which is a lineage of green algae. |
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Definition
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Term
| Two key processes in the sexual life cycles are __________ (or reduction division) and ______________. |
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Definition
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Term
| Sexual reproduction generates ______________, which is important in evolution. |
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Definition
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Term
| In the sexual life cycles of humans and many other animals, the gametes are __________ products of ___________. In other words, in the haploid phase of the life cycle, there is not an intervening _______________ stage in humans, as there are in plants. |
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Definition
| direct; meiosis; multicellular |
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Term
During the diversification of plants, there has been a shift from life cycles in which the ___________ is larger, longer-lived, and more self-sufficient to those in which the ___________ is larger, longer-lived, and more self-sufficient.
In the comparisons which plants is this shift the most evident? |
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Definition
| gametophyte; sporophyte; mosses, ferns, and gymnosperms |
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Term
| In the typical _________ life cycle, the multicellular gametophyte is photosynthetic and free-living. |
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Definition
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Term
| In the typical ________ life cycle, both the multicellular gametophyte and multicellular sporophyte are photosynthetic and free-living |
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Definition
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Term
| In the typical _____________ life cycle, the multicellular sporophyte is photosynthetic and free-living |
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Definition
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Term
| In the gymnosperm life cycle, two distinct types of spores are produced by meiosis, called _____________ and _____________. |
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Definition
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Term
| ____________ give rise via mitosis to multicellular male gametophytes, which then give rise to the male gametes (i.e., sperm). |
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Definition
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Term
| ______________ give rise via mitosis to multicellular female gametophytes, which then give rise to the female gametes (i.e., eggs). |
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Definition
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Term
| There are more than ___________ known species of angiosperms, which is by far the largest number for any plant group. |
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Definition
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Term
| In plants, the haploid phase of the life cycle is called __________ generation and, the diploid phase is called the __________ generation. Thus the life cycles of plants are said to involve "______________". |
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Definition
| gametophyte; sporophyte; alternation of generations |
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Term
Gymnosperms are thus said to be ____________.
By contrast, mosses are ___________, as are most (but not all) ferns. |
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Definition
| heterosporous; homosporous |
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Term
| In terms of their ecological and economic importance, angiosperms are _____________. ________________. and _____________. |
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Definition
| primary producers; sources of food; sources of drugs |
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Term
| Why are angiosperms primary producers? |
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Definition
| In most terrestrial ecosystems, angiosperms account for most of the photosynthetic conversion of radiant energy into chemical energy. Angiosperms thus form the basis for most terrestrial food chains. |
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Term
| What are some examples of food that uses angiosperms? |
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Definition
-all cereal grains and most vegetables, fruits, and nuts are obtained from angiosperms,
- most spices are obtained from angiosperms, and
- most non-alcoholic and alcoholic beverages are made from angiosperms. |
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Term
| How are angiosperms sources of drugs? |
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Definition
| Many angiosperms produce chemicals with significant medicinal properties. Other angiosperms produce chemicals with significant effects on the human central nervous system. |
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Term
| What are examples of chemicals made with angiosperms and what are their medical properties? |
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Definition
Quinine – used in treating malaria
Vincristine – used in treating leukemia
Curare – used as muscle relaxant in open-heart surgery
Diosgenin – used as a precursor to the active ingredient in oral contraceptives |
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Term
| What are chemicals made with angiosperms that affect the human central nervous system? |
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Definition
Mescaline – from peyote cacti (Lophophora)
Opium – from poppies (Papaver)
Cocaine – from cocoa plants (Erythroxylum)
Caffeine – from coffee plants (Coffea) |
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Term
| In angiosperms, the ovules are enclosed within specialized structures called _________ (or pistils), which are contained in the _________. |
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Definition
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Term
| Angiosperms exhibit __________ fertilization and _________ formation. |
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Definition
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Term
| Since angiosperms are heterosporous, the multicellular male gametophyte is the ___________, and the multicellular female gametophyte is the ____________. |
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Definition
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Term
| The vegetative body of a typical angiosperm consists of __________, ___________, and ___________. |
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Definition
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Term
| ___________ are involved in water and nutrient uptake and in support (or anchoring). |
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Definition
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Term
| _________ are involved in the transport of water, nutrients, sugars, etc. between the roots and leaves and in support. |
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Definition
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Term
| __________ carry out photosynthesis. |
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Definition
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Term
| _________ is involved in the transport of water and nutrients, and ____________ is involved in the transport of sugars produced by photosynthesis of other compounds. |
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Definition
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Term
| The upper and lower leaf surfaces are covered by a ______________ to prevent water vapor from diffusing out of the leaf. |
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Definition
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Term
| The waxy cuticle prevents ________ from diffusing into the leaf. This is a major dilemma because the plant needs this for photosynthesis. |
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Definition
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Term
| The _________ (or pore, located in the leaf epidermis) is surrounded by two specialized epidermal cells called __________. |
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Definition
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Term
| What are two physical features of the guard cells that are important to the mechanism of stomatal opening? |
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Definition
1. Specialized bands of inelastic cellulose microfibrils are oriented perpendicular to the long axis of each guard cell, and
2. The cell wall of each guard is thicker on the side close to the stoma than on the side away from the stoma. |
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Term
| What does the basic mechanism of stomatal opening (in sequence) involve? |
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Definition
1. active transport causing potassium ions to move into the guard cells from the surrounding epidermal cells (remember: active transport requires energy),
2. net movement of water into the guard cells to maintain osmotic balance,
3. increased turgidity of the guard cells, and
4. stomatal opening. |
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Term
| A reverse process, first involving ___________ of potassium ions out of the guard cells into the surrounding epidermal cells, results in stomatal ________. |
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Definition
| passive diffusion; closing |
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Term
| Stomata regulates the balance between CO2 uptake and _________ loss. |
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Definition
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Term
| A key process that determines how plants respond in different environments is ______________. |
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Definition
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Term
| Plants obtain all of their chemical energy from _____________ once their seed resources have been depleted. |
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Definition
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Term
| Photosynthesis may be divided into two major sets of reactions that occur in the _____________. |
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Definition
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Term
| The _____________ (also known simply as the “light reactions”) occur in the thylakoid membranes in the chloroplasts. |
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Definition
| light-harvesting reactions |
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Term
| Light energy in the form of photons is absorbed by ____________ and associated accessory pigments. |
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Definition
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Term
| The light energy is converted into chemical energy in the form of _____ and _______. |
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Definition
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Term
| ____________ conversion occurs via a complex series of physical and chemical reactions involving an initial electron donor (H2O), two photosystems (I and II), an electron transport chain, and a final electron acceptor (NADP+). |
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Definition
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Term
| The ______________ (also known as the “dark reactions”) occur in the stroma (or protein-rich matrix) in the chloroplasts. |
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Definition
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Term
| The ________________ consist of a primary reaction by which CO2 is chemically bound (or “fixed”), together with a series of chemical reactions that ultimately yield glucose as a product and that serve to regenerate the primary CO2-acceptor molecule. |
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Definition
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Term
| This series of reactions uses the ATP and NADPH generated by the light-harvesting reactions. |
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Definition
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Term
What is the primary reaction by which CO2 is fixed in most plants? What enzyme is the reaction catalyzed by?
Hint: Ribulose |
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Definition
Bisphosphate + CO2 --> 2 3-phosphohulcerate
Enzyme: ribulose bisphosphate carbozylase (or RuBP carboxylase) |
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Term
| RuBP carboxylase often accounts for more than ___% of the soluble protein in leaves. |
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Definition
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Term
| Photosynthesis consists not only of this series of physical and chemical reactions occurring in the chloroplasts, but also of the ______________ between the leaf and its atmospheric environment. |
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Definition
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Term
| Describe how CO2 reaches the site of carboxylation after it diffuses from the atmosphere to the leaf surface. |
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Definition
| It goes through the stomata, across the intercellular air space, into the cell, across the cytoplasm, and into the chloroplast, where it finally reaches the site of carboxylation. |
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Term
| ____________ is a spontaneous process leading to the net movement of a substance from a region of higher concentration to an adjacent region where that substance has a lower concentration. |
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Definition
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Term
| In the case of CO2, its concentration in the atmosphere is usually much ___________ than its concentration at the site of carboxylation in the chloroplast. |
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Definition
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Term
| A key issue for plants living in dry environments is _________________. |
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Definition
| photosynthetic water-use efficiency |
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Term
| What is the equation for photosynthetic water-use efficiency? What are the units? |
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Definition
amount of CO2 fixed by photosynthesis/amount of H2O lost by transpiration
unit: mol |
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Term
In most plants, the primary fixation product of photosynthesis is the three-carbon compound
_______________ (C3).
However, in some plants, the primary fixation product of photosynthesis is the four-carbon compound _____________ (C4). |
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Definition
| 3-phosphoglycerate; oxaloacetate |
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Term
| In C4 plants, what is the primary reaction by which CO2 is fixed? What enzyme catalyzes the reaction? |
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Definition
Reaction: Phosphoenol pyruvate + CO2 -> oxaloacetate
Enzyme: phosphoenol pyruvate carboxylase (or PEP carboxylase) |
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Term
| The primary reaction of C4 plants occurs in specialized __________ cells in the leaves. |
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Definition
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Term
| Oxaloacetate is converted into malate, which is transported into specialized ___________ cells. |
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Definition
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Term
| What are the two special properties of PEP carboxylase relative to RuBP carboxylase? |
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Definition
1. PEP carboxylase has a much higher affinity for CO2 than does RuBP carboxylase.
2. PEP carboxylase is not competitively inhibited by O2, whereas RuBP carboxylase is. |
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Term
| C4 plants can maintain _________ rates of photosynthesis with lower degrees of stomatal opening than C3 plants. |
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Definition
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Term
| C4 plants have intrinsically _________ photosynthetic water-use efficiencies than C3 plants. |
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Definition
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Term
| C4 plants are most abundant in ______ environments where photosynthetic water-use efficiency is at a premium. |
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Definition
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Term
| A third major biochemical pathway of photosynthesis, known as ___________________, is found in other plants. |
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Definition
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Term
| CAM stands for __________________, so named because it was originally found in the plant family Crassulaceae. |
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Definition
| Crassulacean Acid Metabolism |
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Term
| CAM photosynthesis is now known to occur in about 20 plant families, including those with species such as ______ cacti, _________ cacti, _______ cacti, and ______ from the desert surrounding Tucson. |
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Definition
| saguaro; prickly-pear; barrel; agaves |
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Term
| CAM plants are ___________ (or fleshy), with the leaf or stem cells containing large __________. |
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Definition
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Term
| Meiosis always gives rise to _________ products. |
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Definition
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Term
| CAM plants exhibit a _______________, in which the stomata open during the night and close during the day. |
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Definition
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Term
When the stomata are open at __________, CO2 is fixed by PEP carboxylase into oxaloacetate, via the same reaction as in C4 plants.
_____________ is then converted into malate, which is stored in the large vacuoles. |
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Definition
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Term
| During the ______, when the stomata are _______, the malate is removed from the large vacuoles and decarboxylated, with the released CO2 then being fixed by RuBP carboxylase via a pathway similar to that in C3 plants. |
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Definition
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Term
In CAM plants, the reactions catalyzed by PEP carboxylase and RuBP carboxylase occur within the ________ cells.
This contrasts with the situation in C4 plants, where the reactions catalyzed by PEP carboxylase and RuBP carboxylase occur in _________ cells. |
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Definition
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Term
| The photosynthetic reactions involving PEP carboxylase and RuBP carboxylase are separated in ________ in CAM plants, whereas they are separated in _______ in C4 plants |
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Definition
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Term
| By opening their stomata at night and closing them during the day, CAM plants are able to achieve very ________ photosynthetic water-use efficiencies, typically much _________ than those of C4 plants. |
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Definition
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Term
| CAM plants usually exhibit ______ photosynthetic rates, and thus typically have ______ growth rates. |
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Definition
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Term
| _____________ is a perennial shrub that remains physiologically active throughout the year, even though air temperatures vary greatly from winter to summer. |
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Definition
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Term
| Plants growing under cool winter conditions exhibited ________ photosynthetic rates at ______ leaf temperatures, whereas plants growing under hot summer conditions exhibited _________ photosynthetic rates at ________ leaf temperatures. |
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Definition
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Term
| What did Stanford biologists find when they analyzed the biochemical properties properties of leaves of creosote bush and other species? |
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Definition
1. leaves of plants growing under cool winter conditions had higher levels of the enzymes fructose-phosphate phosphatase and RuBP carboxylase than leaves of plants growing under hot summer conditions, and
2. leaves of plants growing under hot summer conditions exhibited an increase in the thermal stability of the reactions associated with the thylakoid membranes in the chloroplasts relative to leaves of plants growing under cool winter conditions. |
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