28. Plants

Three of the following are evidence that charophytes are the closest algal relatives of plants. Select the exception. a. similar sperm structure b. the presence of chloroplasts c. similarities in cell wall formation during cell division d. genetic similarities in chloroplasts

What important role does lignin play in vascular plants? a. It is the major component of the cuticle, which prevents plants from drying out. b. It forms the outer layer of pollen grains. c. It forms the tough, rigid cell walls of water-conducting cells. d. It nourishes the embryo in seed plants.

How is energy transferred among antenna pigment molecules? a. by heat b. by redox reactions c. by fluorescence d. by resonance

Which of the following characteristics of plants is absent in their closest relatives, the charophyte algae? a. chlorophyll b b. cellulose in cell walls c. sexual reproduction d. alternation of multicellular generations

The appearance of cuticle and stomata correlated with what event in the evolution of green plants? a. the first upright growth forms b. the first woody tissues c. growth on land d. the evolution of the first water-conducting tissues

Why is chlorophyll green? a. It absorbs all wavelengths in the visible spectrum. b. It absorbs wavelengths only in the red portions of the spectrum (680–700 nm). c. It absorbs wavelengths only in the blue part of the visible spectrum (450–480 nm). d. It absorbs wavelengths in only the blue and red parts of the visible spectrum.

In angiosperms, which of the following is correctly paired with its chromosome count? (A)microspore—n (B)zygote—n (C)egg—2n (D)megaspore—2n

In plants, which of the following are produced by meiosis? a. haploid gametes b. diploid gametes c. haploid spores d. diploid spores

Evaluate the following statements regarding seeds. Select True or False for each statement. T/F They contain an embryo. T/F They contain nutritive tissue for the embryo. T/F They consist entirely of diploid cells. T/F They are also referred to as spores.

At what point in photosynthesis is the electromagnetic energy of light first converted into chemical energy?

Why is the chlorophyll in chloroplasts less likely to produce fluorescence compared to extracted chlorophyll molecules?

What does it mean to say that a life cycle is gametophyte dominant versus sporophyte dominant?

Identify each of the following structures as haploid or diploid. a. sporophyte b. spore c. gametophyte d. zygote

EVOLUTION CONNECTION The history of life has been punctuated by several mass extinctions. For example, the impact of a meteorite may have wiped out most of the dinosaurs and many forms of marine life at the end of the Cretaceous period (see Concept 25.4). Fossils indicate that plants were less severely affected by this mass extinction. What adaptations may have enabled plants to withstand this disaster better than animals?

EVOLUTION CONNECTION DRAW IT Draw a phylogenetic tree that represents our current understanding of evolutionary relationships between a moss, a gymnosperm, a lycophyte, and a fern. Use a charophyte alga as the outgroup. (See Figure 26.5 to review phylogenetic trees.) Label each branch point of the phylogeny with at least one derived character unique to the clade descended from the common ancestor represented by the branch point.

The evolution of cuticle presented plants with a challenge that threatened their ability to live on land. Describe this challenge, and explain why stomata represent a solution. Compare and contrast stomata with the pores found in liverworts.

Predict how the following conditions would affect the production of O2, ATP, and NADPH and state whether noncyclic or cyclic electron flow would occur in each;(3) blue and red photons hit a chloroplast, but a proton channel has been introduced into the thylakoid membrane, so it is fully permeable to protons.

An investigator exposes chloroplasts to 700-nm photons and observes low O2 production, but high ATP production. Which of the following best explains this observation? a. The electrons from water are directly transferred to NADP+, which is used to generate ATP. b. Photosystem II is not splitting water, and the ATP is being produced by cycling electrons via photosystem I. c. The O2 is being converted to water as a terminal electron acceptor in the production of ATP. d. Electron transport has stopped and ATP is being produced by the Calvin cycle.

What is a pollen grain?

a. sperm-producing gametophyte

b. egg-producing gametophyte

c. sperm-producing sporophyte

d. sperm