Question 1

Which structure is common to both gymnosperms and angiosperms?

Accepted Answer

Both gymnosperms and angiosperms have ovules, which are structures that contain the female reproductive cells and develop into seeds after fertilization. The other structures listed are specific to either gymnosperms (stigma, carpel) or angiosperms (ovary, anthers).

Question 2

The generative cell of male angiosperm gametophytes is haploid. This cell divides to produce two haploid sperm cells. What type of cell division does the generative cell undergo to produce these sperm cells?

Accepted Answer

The generative cell undergoes mitosis to produce two haploid sperm cells, maintaining the haploid number of chromosomes.

Question 3

Use the following information to answer the question(s) below.
Harold and Kumar are pre-med and pre-pharmacy students, respectively. They complain to their biology professor that they should not have to study about plants because plants have little relevance to their chosen professions.
-Which adaptations of land plants are likely to provide Harold with future patients?
I. sporophyte dominance
II. defenses against herbivory
III. adaptations related to wind dispersal of pollen

Accepted Answer

Defenses against herbivory could be relevant to pharmacy, as plants produce many secondary metabolites that can have medicinal properties. Adaptations related to wind dispersal of pollen are unlikely to have relevance to pharmacy or medicine. Sporophyte dominance is relevant to all biology, but may not have direct applicability to medicine or pharmacy.

Question 4

A botanist discovers a new species of land plant with a dominant sporophyte, chlorophylls a and b, and cell walls made of cellulose. In assigning this plant to a phylum, which of the following, if present, would be LEAST useful?

Accepted Answer

Spores are present in many plant phyla, including non-seed plants like ferns and mosses, making them less useful for distinguishing between major plant groups.

Question 5

Which of the following is a characteristic of all angiosperms?

Accepted Answer

Double internal fertilization is a characteristic of all angiosperms. They have two sperm cells, one that fertilizes the egg to form the zygote and another that combines with two polar nuclei to form the endosperm.

Question 6

Use the following information to answer the question(s) below.
The Brazil nut tree, Bertholletia excels, is native to tropical rain forests of South America. It is a hardwood tree that can grow to over 50 meters tall, is a source of high-quality lumber, and is a favorite nesting site for harpy eagles. As the rainy season ends, tough-walled fruits, each containing 8-25 seeds (Brazil nuts), fall to the forest floor. Brazil nuts are composed primarily of endosperm. About $50 million worth of nuts are harvested each year. Scientists have discovered that the pale yellow flowers of Brazil nut trees cannot fertilize themselves and admit only female orchid bees as pollinators. The agouti (Dasyprocta spp.), a cat-sized rodent, is the only animal with teeth strong enough to crack the hard wall of Brazil nut fruits. It typically eats some of the seeds, buries others, and leaves still others inside the fruit, which moisture can now enter. The uneaten seeds may subsequently germinate.
-Entrepreneurs attempted, but failed, to harvest nuts from plantations grown in Southeast Asia. Attempts to grow Brazil nut trees in South American plantations also failed. In both cases, the trees grew vigorously, produced healthy flowers in profusion, but set no fruit. Consequently, what is the likely source of the problem?

Accepted Answer

The statement that the Brazil nut trees cannot fertilize themselves and require female orchid bees as pollinators suggests that there may be a pollination failure issue. The failure of attempts to grow Brazil nut trees in plantations in Southeast Asia and South America, despite the healthy growth and profusion of flowers, also supports this idea.

Question 7

Which group of seedless vascular plants was the first to evolve roots?

Accepted Answer

Club mosses were among the first group of seedless vascular plants to evolve roots, which allowed them to anchor themselves and absorb water and nutrients from the soil.

Question 8

The fruit of the mistletoe, a parasitic angiosperm, is a one-seeded berry. In members of the genus Viscum, the outside of the seed is viscous (sticky), which permits the seed to adhere to surfaces such as the branches of host plants or the beaks of birds. What should be expected of the fruit if the viscosity of Viscum seeds is primarily an adaptation for dispersal rather than an adaptation for infecting host plant tissues? It should _________.

Accepted Answer

If the viscosity of Viscum seeds is primarily an adaptation for dispersal, it would be expected that the fruit would contain nutrients that would be beneficial to the organism(s) dispersing it, such as birds. This would increase the likelihood that the bird would consume and subsequently disperse the seed. Drab coloration, camouflage, secretion of enzymes to digest bark, or containing chemicals to cause vomiting would not directly aid in dispersal.

Question 9

Because they are morphologically simple, Psilotophyta (whisk ferns) have traditionally been thought to be a basal group in the radiation of land plants. Molecular phylogenies have challenged this hypothesis and support the alternative hypothesis that they________.

Accepted Answer

Psilotophyta (whisk ferns) are considered to have lost complex structures in their lineage, according to molecular phylogenies, rather than being a basal group due to their morphological simplicity. This suggests a more derived position within the plant kingdom through the process of simplification from more complex ancestors.

Question 10

Use the following description to answer the question(s) below.
Cycads, a mostly tropical phylum of gymnosperms, evolved about 300 million years ago and were dominant forms during the Age of the Dinosaurs. Though their sperm are flagellated, their ovules are pollinated by beetles. These beetles get nutrition by eating pollen and microsporophyll tissue and shelter within the male cones (they are dioecious). Upon visiting megasporophylls on nearby female plants, which become attractively aromatic and warm (but are not palatable), the beetles transfer pollen to the exposed ovules. Cycad megasporophyll tissues synthesize neurotoxins, some of which is transferred to the seeds, that are effective against most animals, including humans.
-Which feature of cycads distinguishes them from most other gymnosperms?
I. They have exposed ovules.
II. They have flagellated sperm.
III. They are pollinated by animals.

Accepted Answer

I is incorrect because many gymnosperms have exposed ovules. II is incorrect because some other gymnosperms, such as ginkgoes, also have flagellated sperm. III is correct and distinguishes cycads from most other gymnosperms, which are wind-pollinated.

Question 11

Use the following information to answer the question(s) below.
Harold and Kumar are pre-med and pre-pharmacy students, respectively. They complain to their biology professor that they should not have to study about plants because plants have little relevance to their chosen professions.
-Which of the following lines of evidence would best support your assertion that a particular plant is an angiosperm?

Accepted Answer

Angiosperms are characterized by the absence of gametangia, which are structures that produce gametes in other plant groups.

Question 12

What is TRUE about the genus Sphagnum?

Accepted Answer

Sphagnum is a genus of mosses that are known to be an important carbon sink. These mosses absorb carbon dioxide from the atmosphere during their growth and help to reduce the amount of carbon dioxide in the air.

Answer: D
 Sphagnum is sometimes known as peat moss because it accumulates to form peat, a material that can be harvested and burned as a fuel. Peat is also an important ingredient in some horticultural products, such as soil amendments and potting mixes.

A, B, and C are incorrect:
 Sphagnum is not a liverwort, and it typically grows in wetland habitats, not grasslands. While it can be used in horticulture, it is not usually used as a direct fertilizer.

Question 13

Which of the following statements is TRUE of the pine life cycle?

Accepted Answer

Conifer pollen grains contain male gametophytes. This is because the male gametophyte develops within the pollen grain and is released during pollination to fertilize the female gametophyte within the ovule of the pine cone. Choices A, B, C, and E are incorrect because cones are not homologous to the capsules of moss plants, the pine tree is not a gametophyte, male and female gametophytes are not in close proximity during gamete synthesis, and double fertilization is not a common phenomenon in pine trees.

Question 14

Which plant group is notable for the independence of gametophyte and sporophyte generations from each other?

Accepted Answer

Ferns are notable for having distinct and independent gametophyte and sporophyte generations, unlike other plant groups where one generation might be dominant or dependent on the other.

Question 15

Arrange the following structures, which can be found on male pine trees, from the largest structure to the smallest structure (or from most inclusive to least inclusive).
1) sporophyte
2) microspores
3) microsporangia
4) pollen cone
5) pollen nuclei

Accepted Answer

The sporophyte is the largest structure as it refers to the entire male pine tree. The pollen cone is next in size as it is a structure found on the tree itself. The microsporangia are smaller structures contained within the cone. Microspores are even smaller structures produced by the microsporangia, and pollen nuclei are the smallest structures as they are contained within the pollen grain itself. Therefore, the correct order from largest to smallest would be 1, 4, 3, 2, 5.

Question 16

Orchid bees are to Brazil nut trees as ________ are to pine trees.

Accepted Answer

The answer of Orchid bees are to Brazil nut trees...

Question 17

Angiosperms are the most successful terrestrial plants. Which of the following features is unique to them and helps account for their success?

Accepted Answer

Fruits enclosing seeds are a unique feature of angiosperms that provides protection and helps in effective dispersal of seeds. This has contributed to their success as they can colonize new habitats and environments with greater ease.

Question 18

Where are you LEAST likely to see green algae?

Accepted Answer

Green algae require water to grow and are typically found in aquatic environments or moist habitats. Dry rock in meadows would not provide an environment conducive to the growth of green algae, making it the least likely option. Option A, B, D, and E are all plausible habitats for green algae growth.

Question 19

Liverworts, hornworts, and mosses are grouped together as Bryophytes. Besides not having vascular tissue, what do they all have in common?

Accepted Answer

Liverworts, hornworts, and mosses all require water for their reproduction as they do not have true roots, stems, or leaves and cannot transport water and nutrients internally. Thus, they rely on water for the dispersal of their reproductive cells.

Quiz 28: Green Algae and Land Plants