Highest_priority_cards_12_-_all_duplicates Flashcards
Q: Reasons plants are important to ecosystems/life? (uses in human society is separate card)
Key roles in ecosystems: producers (make their own food; serve as energy source in food chain), food source, shelter for other animals, prevent erosion etc.
Oxygen source (via photosynthesis); needed for respiration in other organisms.
Tools for use by non-humans.
Their evolution onto land created new biomes and habitats, e.g., trees gave vertebrates new niches to fill
Q: Uses of plants in human society?
Tools, structures, rubber for tires…
Fiber for clothing, paper…
Food, spices. (30,000 edible plant species, 7,000 species are cultivated for food -E.O. Wilson)
Fuel.
Decoration, scents.
Medicine and drugs.
-E.O. Wilson, an American biologist, estimated that 41% of prescription drugs used in the US come from living organisms and 70% of anticancer drugs come from rain forest plants.
-In 2010, Italian scientists developed a way of turning rattan wood into bone that is almost identical to the human tissue. Rattan is the name for approximately 600 species of palms.
-Widespread example immediately relevant to most people: Aloe plant contains compounds that soothe burns.
Q: Value of oxygen in the atmosphere in the development of life on our planet?
The build up of oxygen in the air allowed for the evolution of aerobic organisms, who take in oxygen and release carbon dioxide during respiration.
Respiration is a key component to life in most organisms.
Q: Early evolution of plants?
-All plants evolved from a common ancestor.
-Plants began in the seas as aquatic green algae and moved to land as competition for resources increased. This was around the time of the first vertebrates. It is generally recognized that the colonization of land by plants and their subsequent radiation and diversification are profoundly important episodes in the history of life.
-Plants brought oxygen into the air/water that animals needed for respiration.
-Created new biomes and habitats.
-Faced new challenges when moving onto land (separate flashcard).
Q: Plant adaptations to life outside of the water?
Needed:
-Structural support for their bulk.
-Way to absorb nutrients on land.
-Way to conserve water.
-Mechanism for reproduction outside of a watery environment.
Adaptations:
-Cellulose as a component of the cell wall. Provided protective framework for a plant cell to survive. Reinforced plant’s structure, helped keep their shape, allowed plants to grow to greater heights.
-Seeds. Protected embryo from parasites, drying out, digestive juices of animals, and excessive temperatures.
Q: Which group of plants was the first to develop wood? Why is this a notable development?
Nonflowering plants (gymnosperms).
Support enabled tall stature. Structures provide habitats for animals.
Q: Plant pollen dispersal mechanisms and strategies? Which groups use each mechanism?
Plants have evolved two means of dispersing pollen:
-Wind
–Must produce copious amount of pollen because chance of landing on correct species is low.
–Some trees release their pollen before leafing out because there is less blockage by the leaves.
–Used by nonflowering plants. E.g., conifers. No showy flowers (brightly colored petals, fragrances, and nectar would be waste of material and energy)
–Wind-pollinated plants are rare in tropical forests. More are seen in Northern temperate forests (of, e.g., North America).
-Pollination by animals (e.g., bees, butterflies, birds, bats)
–Can use less pollen because insect flies from flower to flower increasing the probability the pollen would land on the same species.
–Depends on adaptations that attract the insect: scents, colors, shapes, and foods.
–Adaptations that increased the plant’s distinctiveness were advantageous.
–Seeds need time to mature and the attention of animals is discouraged until then. Plant-pollinator schedule coordination adaptations: Buds are green and closed until the flowers are ready to be pollinated. Flower pollination may occur later in summer when insects peak. Fruit stays green until seed has developed.
–Different species stagger their pollination to avoid competition for the pollinators at the same time.
Q: Key factor in the diversity and success of the flowering plants that dominate today?
Beneficial interaction between pollinators. (details on other cards)
Q: What percentage of flowering plants are pollinated by animals?
90%
Q: Pollination
The process by which pollen is transferred from the anther (male part) to the stigma (female part) of the plant, thereby enabling fertilization and reproduction.
Q: Discuss the ongoing mutual adaptations of the plant and the pollinator. Is there a key term for this?
-Coevolution: The process of reciprocal evolutionary change that occurs between pairs of species or among groups of species as they interact with one another; two (or more) species reciprocally affect each other’s evolution.
-Both the plant and the pollinator benefit from and exert selective pressure on the other, so they evolve together.
-Angiosperms provide pollen, nectar, and fruit to pollinators as a source of food. In return, pollinators pollinate the plants.
-The coevolution of flowering plants and pollinators is a key to their successful radiation and abundance today.
-Compared to wind-pollination, requires less pollen because insect flies from flower to flower increasing the probability the pollen would land on the same species.
Q: Name three examples of things a plant may provide to a pollinator as payment
Pollen, nectar, fruit.
Q: Plant adaptations for attracting the correct pollinator and for guiding pollinator to nectar?
-Unique color patterns.
-Unique fragrances.
-Visual guides on petals that attract and guide pollinators to their nectar.
-Some visual cues that can only be seen in ultraviolet light, which limits the type of animal that can see the cues.
-Brightly colored flowers attract daytime pollinators whereas white or other light colored flowers are meant to attract night-time pollinators such as moths and bats.
-Lighter colored flowers tend to have stronger smells associated with them. Helps guide a pollinator who may not be navigating by sight alone.
Q: Give an example of a flower that provides something besides food to its pollinator.
The Arctic poppy flower follows the sun collecting the sun’s rays and warmth. The warmth attracts insects which are unable to generate heat of their own. These insects in turn pollinate the poppies.
Q: Uses of fragrances in plants.
Aromas developed for two main reasons:
-Leaf, root, and bark fragrances defend a plant against being browsed or chewed.
-Flower and fruit fragrances attract animals for pollination and seed dispersal.
The goals of these two strategies are often opposed to each other with bad smelling leaves and sweet smelling flowers.
Also:
-Nectar can sometimes protect the plant. Some flowering plants will secrete nectar on the outside of the plant that will attract predatory insects which then eat the insects that attack the plants.
-Plants also release airborne signals to warn of predators, giving other members of their species time to mount a defense
