28. Plants

Where in an angiosperm would you find a megasporangium? a. in the style of a flower b. enclosed in the stigma of a flower c. within an ovule contained within an ovary of a flower d. packed into pollen sacs within the anthers found on a stamen

Which of the following is a key feature of seed plants facilitating life on land? (A)homospory (B)pollen (C)reduced sporophytes (D)spores

Key features of seed plants facilitating life on land include three of the following four traits. Select the exception. a. homospory b. pollen c. reduced gametophytes d. seeds

With respect to angiosperms, which of the following is incorrectly paired with its chromosome count? a. egg—n b. megaspore—2n c. microspore—n d. zygote—2n

Which of the following actions correctly describe a role performed by at least one type of intercellular connection? Select True or False for each statement. T/F Allows communication between adjacent cells. T/F Forms a watertight barrier between the cells. T/F Uses components of the extracellular matrix to indirectly connect adjacent cells. T/F Associates with cytoskeletal components to resist pulling forces.

Which of the following is a characteristic that distinguishes gymnosperms and angiosperms from other plants? (A)alternation of generations (B)independent gametophytes (C)vascular tissue (D)ovules

Which of the following is not a characteristic that distinguishes gymnosperms and angiosperms from other plants? a. dependent gametophytes b. ovules c. pollen d. alternation of generations

Gymnosperms and angiosperms have the following in common except a. seeds. b. pollen. c. ovaries. d. ovules.

DRAW IT Use the letters a–d to label where on the phylogenetic tree each of the following derived characters appears. a. flowers b. embryos c. seeds d. vascular tissue

Explain the difference between homosporous and heterosporous plants. Where are the microsporangium and megasporangium found in a tulip? What happens to the spores that are produced by these structures?

Steroid hormones, like most lipid-soluble signaling molecules, are processed directly. How does the absence of a signal transduction cascade in the processing of steroid hormones affect the cellular response that is possible?

Angiosperms such as grasses, oaks, and maples are wind pollinated. The ancestors of these subgroups were probably pollinated by insects, however. As an adaptive advantage, why might a species 'revert' to wind pollination? (Hint: Think about the costs and benefits of being pollinated by insects versus wind.) Why is it logical to observe that wind-pollinated species usually grow in dense stands containing many individuals of the same species? Why is it logical to observe that in wind-pollinated deciduous trees, flowers form very early in spring—before leaves form?

You have been hired as a field assistant for a researcher interested in the evolution of flower characteristics in orchids. Design an experiment to determine whether color, size, shape, scent, or amount of nectar is the most important factor in attracting pollinators to a particular species. Assume that you can change any flower's color with a dye and that you can remove petals or nectar stores, add particular scents, add nectar by injection, or switch parts among species by cutting and gluing.

Which of the following are present in angiosperms but not in gymnosperms?

A. seeds

B. pollen

C. ovaries

D. ovules