28. Plants

Which of the following adaptations is common to all seed plants?

Which one of the following is true of seed plants but not true of seedless plants?

The closest seedless relatives of seed plants produce one kind of spore that gives rise to a bisexual gametophyte. What does this suggest about the ancestors of seed plants?

The eggs of seed plants are fertilized within ovules, and the ovules then develop into __________.

The cells within pollen grains are __________ and together comprise the __________.

Besides the plant tissue that humans ingest, which angiosperm tissue is most directly important for human survival?

Six major crops˜wheat, rice, maize, potatoes, cassava, and sweet potatoes˜contribute disproportionately to human diets. What percentage of all the calories consumed by humans is supplied by these crops?

Which of the listed examples is evidence provided by living gymnosperms of an evolutionary transition between seedless and seed plants?

Which of the following best states the advantages that seeds have over spores?

Which gymnosperm phylum is characterized by large cones and fern-like leaves and thrived during the Mesozoic?

Dietary supplements and decongestants containing ephedrine have recently become more strongly regulated in the United States. Which phylum contains the plant from which ephedrine is extracted?

What global change occurring between the Carboniferous period and the Permian period likely contributed to the success of the gymnosperms?

What is located in the scalelike structures packed densely in pollen cones?

Each pollen grain of a gymnosperm contains a __________.

In ovulate cones, megasporocytes undergo __________ and produce __________ megaspores.

Which of the following lists of features characterizes eudicots?

In a typical conifer, how long does it take for fertilization to occur after pollination?

The diploid generation of the plant life cycle always __________.

Which types of angiosperms would most likely be wind-pollinated rather than animal-pollinated?

The vast majority of angiosperms with two cotyledons formerly classified as __________ are now classified as __________.

Like gymnosperms, many grasses and angiosperm trees are wind-pollinated. To conserve energy, these angiosperms do not produce complete flowers (complete flowers have all four of the basic parts). Which part would be unnecessary for wind-pollinated angiosperms?

The portion of a flower that receives the pollen is the __________.

In gymnosperms, the seed coat develops from the integument. In angiosperms, the seed coat develops from the __________.

During pollination, pollen grains are transferred from the __________ to the __________.

A pea pod is formed from __________. A pea inside the pod is formed from __________.

After fertilization, the __________ develops into a seed, and the __________ develops into a fruit.

Which of the following best describes the function of fruits?

A plant is said to be cross-pollinated if __________.

The triploid nucleus of the embryo sac develops into the __________.

The pollen tube releases two sperm cells into the embryo sac. The result of this is the __________.

Of the following, which is a difference in how reproduction occurs in gymnosperms compared to angiosperms?

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

Angiosperms are different from all other plants because only they have a. a vascular system. b. flowers. c. seeds. d. a dominant sporophyte phase.

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

Which of the following structures produce eggs and sperm? (Explain your answer.) a. fern sporophytes b. moss gametophytes c. the anthers of a flower d. moss sporangia

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

The eggs of seed plants are fertilized within ovules, and the ovules then develop into a. seeds. b. spores. c. fruit. d. sporophytes.

The diploid sporophyte stage is dominant in the life cycles of all of the following except a pine tree. a rose bush. a fern. a moss.

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

Which of the following terms includes all the others? a. angiosperm b. gymnosperm c. vascular plant d. fern e. seed plant

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?

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?

Compare a seed plant with an alga in terms of adaptations for life on land versus life in the water.

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.