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.