Thinking Critically/Review Questions
Dr. Maggie Boylan
January 15, 2013
Chapter 1: Plants in Our Lives
Review Questions: 1. What are the characteristics of angiosperms?
Angiosperms are characterized by flowers and fruits. Angiosperms also contain four whorls of parts: the stamen, sepals, petals and one or more carpels. They are also unique because their sexual reproductive structures are contained in a flower.
Thinking Critically: 1. Plants are crucial to the existence of many organisms, including human beings. Could life on Earth exist without plants? Explain.
Life on Earth would be impossible without plants. Plants are essential for the human diet as well as for fuel to cook meats. Without plants for food one could not live for a long period time and without plants we do not have fuel to cook meat. Eating raw meat could subject a human to certain diseases leading to death. Plants are the base of most food chains and without it other organisms such as cows, goats, and pigs would also die. Plants also give other living organisms oxygen which is vital to survival.
Chapter 5: Plant Life Cycle: Flowers
Review Questions: 1. Describe the parts of a flower.
Sepals: Leafy structures that cover the unopened flower bud and protect the flower bud.
Calyx: The whole whorl of sepals of a single flower.
Corolla: The petals that make up the next whorl of flower parts.
Perianth: Where the calyx and corolla constitute.
Androecium: The whorl of male structures.
Anther: Pollen-producing, part of the stamen.
Filament: Stalk of the stamen that supports the anther.
Pollen: A fine powdery substance that is discharged from the androecium.
Stigma: The extended tip of the style.
Style: A slender column that rises from the top of the ovary.
Ovules: Vary in number and will eventually become seeds.
Ovary: Found within the gynoecium and bears ovules.
Gynoecium: The whorl of female structures.
Petals: Attract the animal pollinators.
Stamens: Contain pollen which will produce sperm.
Carpels: Or also called the pistil (old term) contains a swollen base or ovary which also contains the eggs.
Receptacle: also known as the stem and holds the flower’s organs.
Bracts: Found only in some flowers and located on the outside of the calyx. They appear leaf like or petal-like and can be various sizes.
2. What is the general appearance of a wind-pollinated flower? Of an animal-pollinated flower? Take a walk in a garden or tour a greenhouse and try to determine whether the flower is wind- or animal-pollinated by examining the flower’s structure.
Wind-pollinated flowers are small and inconspicuous while animal-pollinated flowers have bright, showy petals and fragrant aromas they are also rich in nectar.
Thinking Critically: 1. The coevolution of flowers and animal pollinators is one of the marvels of nature and can greatly enhance the rate of successful pollinations. Few flowers, however, are so specialized that they can only be pollinated by only one type of animal. Why would extreme specialization between pollinator and flower be at once both an advantage and a drawback?
The extreme specialization between a flower and pollinator is both an advantage and a drawback. The relationship between the two ensures the success of pollination. The drawback is the availability of the pollinator if the population of the pollinator is low the occurrences of pollination will be as well. Since the plant can only be pollinated by one type of animal there are no other alternatives.
2. In many perfect flowers, the stamens and carpels mature at different times. For instance, the anthers of a flower may release pollen while the stigma is still immature and unreceptive, and by the time the stigma is receptive, the anthers have released all of their pollen and are empty. What is the advantage of this adaption?
This adaptation decreases the chances that the flower will…