Question 1

Compared to animal-pollinated plants, wind-pollinated angiosperms ________.

Accepted Answer

Wind-pollinated angiosperms produce much more pollen because wind dispersal is random and not targeted, requiring a larger quantity of pollen to increase the chances of successful pollination.

Question 2

Use the information to answer the following question.
The Brazil nut tree, Bertholletia excels (n = 17), is native to tropical rain forests of South America. It is a hardwood tree that can grow to over 50 meters tall, a source of high-quality lumber, and 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 then enter and allow the remaining seeds to germinate.
Animals that consume Brazil nuts derive nutrition mostly from tissue whose nuclei have how many chromosomes?

Accepted Answer

The answer of Use the information to answer the following...

Question 3

Which of the following sex and generation combinations directly produces the fruit of angiosperms?

Accepted Answer

The fruit of angiosperms is produced by the female sporophyte generation, which develops from the fertilized ovule and includes the ovary that matures into the fruit.

Question 4

Use the information to answer the following question.
The 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 from the pollen and shelter from the microsporophylls. Upon visiting megasporophylls, the beetles transfer pollen to the exposed ovules. In cycads, pollen cones and seed cones are borne on different plants. Cycads synthesize neurotoxins, especially in the seeds, that are effective against most animals, including humans.
Which feature of cycads makes them similar to many angiosperms?

Accepted Answer

Cycads are similar to many angiosperms because they are pollinated by animals, which is a common feature in angiosperms.

Question 5

Which of the following is a characteristic of all angiosperms?

Accepted Answer

Angiosperms are characterized by double fertilization, a unique process where one sperm fertilizes the egg, forming a zygote, and the other fuses with two polar nuclei to form the endosperm, providing nutrition to the developing embryo.

Question 6

Among plants known as legumes (beans, peas, alfalfa, clover, for example) the seeds are contained in a fruit that is itself called a legume, better known as a pod. Upon opening such pods, it is commonly observed that some ovules have become mature seeds, whereas other ovules have not. Thus, which of the following statements is/are likely accurate?

Accepted Answer

The statement that some ovules have become mature seeds while others have not suggests that not all ovules have been fertilized. This can occur if pollen tubes did not enter all of the ovules. However, fruit can still develop even if not all ovules have been fertilized, which is known as parthenocarpy. Therefore, option C is the most likely accurate statement. Options A, B, and D are not supported by the given information.

Question 7

Use the information to answer the following question.
The Brazil nut tree, Bertholletia excels (n = 17), is native to tropical rain forests of South America. It is a hardwood tree that can grow to over 50 meters tall, a source of high-quality lumber, and 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 then enter and allow the remaining seeds to germinate.
If a female orchid bee has just left a Brazil nut tree with nectar in her stomach, and if she visits another flower on a different Brazil nut tree, what is the sequence in which the following events should occur?

Accepted Answer

Pollination occurs first when pollen is transferred to the stigma. Then, the pollen tube emerges from the pollen grain, grows down the style, and enters the micropyle. Finally, double fertilization occurs when sperm cells fertilize the egg and central cell.

Question 8

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, as mitosis is the process that results in two genetically identical haploid cells from a haploid parent cell.

Question 9

If one were to propose a new taxon of plants that included all the plants that are pollinated by animals, but excluded all plants that are not pollinated by animals, then this new taxon would be ________.

Accepted Answer

A polyphyletic group is one that includes organisms from different evolutionary lineages, which is the case here as animal pollination has evolved independently in different plant lineages.

Question 10

Use the information to answer the following question.
Oviparous (egg-laying) animals have internal fertilization (sperm cells encounter eggs within the female's body). Yolk and/or albumen is (are) provided to the embryo, and a shell is then deposited around the embryo and its food source. Eggs are subsequently deposited in an environment that promotes their further development, or are incubated by one or both parents.
The shell of a fertilized animal egg has what type of analog in angiosperms?

Accepted Answer

The shell of a fertilized animal egg is analogous to the seed coat of an angiosperm. Both structures protect and provide nutrients to the developing embryo. Endosperm is a food source for the developing plant embryo, carpels are reproductive structures in a flower, and fruit is the mature ovary of a flower containing seeds.

Question 11

What adaptations should one expect of the seed coats of angiosperm species whose seeds are dispersed by frugivorous (fruit-eating) animals, as opposed to angiosperm species whose seeds are dispersed by other means?

Accepted Answer

Angiosperm species whose seeds are dispersed by frugivorous animals need seed coats that can withstand high acidity and resist the animal's digestive enzymes, as the seeds can be ingested and excreted intact. This adaptation increases the chances that the seeds will remain viable after passing through the animal's digestive system and be dispersed over a wider area.

Question 12

Stamens, sepals, petals, carpels, and pinecone scales are all ________.

Accepted Answer

Stamens, sepals, petals, carpels, and pinecone scales are all considered modified leaves, as they are specialized structures that have evolved from leaf-like origins to perform specific functions in plants.

Question 13

Use the information to answer the following question.
Oviparous (egg-laying) animals have internal fertilization (sperm cells encounter eggs within the female's body). Yolk and/or albumen is (are) provided to the embryo, and a shell is then deposited around the embryo and its food source. Eggs are subsequently deposited in an environment that promotes their further development, or are incubated by one or both parents.
The yolk of an animal egg has what type of analog in angiosperms?

Accepted Answer

The yolk of an animal egg is similar in function to the endosperm in angiosperms, as both provide nutrients to the growing embryo.

Question 14

In onions (Allium), cells of the sporophyte have 16 chromosomes within each nucleus. Match the number of chromosomes present in each of the following onion tissues. How many chromosomes should be in a megasporangium nucleus?

Accepted Answer

All cells in the sporophyte of onions have 16 chromosomes. Therefore, all tissues in the sporophyte will also have 16 chromosomes. The megasporangium is a part of the sporophyte and thus will have 16 chromosomes in each nucleus. The correct choice is B, which represents the number of chromosomes in each onion tissue.

Question 15

Use the information to answer the following question.
Oviparous (egg-laying) animals have internal fertilization (sperm cells encounter eggs within the female's body). Yolk and/or albumen is (are) provided to the embryo, and a shell is then deposited around the embryo and its food source. Eggs are subsequently deposited in an environment that promotes their further development, or are incubated by one or both parents.
The laying of eggs has what type of analog in angiosperms?

Accepted Answer

The answer of Use the information to answer the following...

Question 16

In onions (Allium), cells of the sporophyte have 16 chromosomes within each nucleus. Match the number of chromosomes present in each of the following onion tissues. How many chromosomes should be in an embryo nucleus after fertilization?

Accepted Answer

All cells of the sporophyte have 16 chromosomes within each nucleus, so all tissues in the onion plant should have 16 chromosomes. After fertilization, the embryo nucleus would have a total of 32 chromosomes because it receives 16 chromosomes from the male gamete (sperm) and 16 chromosomes from the female gamete (egg), totaling to 32 chromosomes. Therefore, the answer is B.

Question 17

Use the information to answer the following question.
Oviparous (egg-laying) animals have internal fertilization (sperm cells encounter eggs within the female's body). Yolk and/or albumen is (are) provided to the embryo, and a shell is then deposited around the embryo and its food source. Eggs are subsequently deposited in an environment that promotes their further development, or are incubated by one or both parents.
The internal fertilization that occurs prior to shell deposition has what type of analog in angiosperms?

Accepted Answer

In angiosperms, the pollen tube must grow and deliver sperm nuclei to the ovule for fertilization to occur, which is analogous to the internal fertilization that occurs in oviparous animals before shell deposition.

Question 18

Mistletoe is a plant that lives on trees and gains nutrition from them (that is, it is a parasite). The fruit of the mistletoe is a one-seeded berry and is consumed by birds. 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? The fruit ________.

Accepted Answer

If the viscosity of Viscum seeds is primarily an adaptation for dispersal, then it is likely that the fruit is nutritious to the dispersing organisms (birds). This would increase the likelihood that birds would eat the fruit and help to disperse the seeds. Options A and B are not related to the viscosity of the seeds, and option D suggests that the seeds have an adaptation for infecting host plant tissues, which is not relevant to this question.

Question 19

Arrange the following structures from largest to smallest, assuming that they belong to two generations of the same angiosperm.

Accepted Answer

The carpel is the largest structure as it encompasses the ovary, which contains the ovules. The ovules contain the embryo sac, which houses the egg. Therefore, the correct order from largest to smallest is: carpel, ovary, ovule, embryo sac, egg. Choice D is the only option that follows this sequence.

Question 20

Use the information to answer the following question.
The 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 from the pollen and shelter from the microsporophylls. Upon visiting megasporophylls, the beetles transfer pollen to the exposed ovules. In cycads, pollen cones and seed cones are borne on different plants. Cycads synthesize neurotoxins, especially in the seeds, that are effective against most animals, including humans.
If the beetles survive by consuming cycad pollen, then whether the beetles should be considered mutualists with, or parasites of, the cycads depends upon the ________.

Accepted Answer

Whether the beetles should be considered mutualists or parasites depends on how their activities affect cycad reproduction overall. If the beetles help pollinate the cycads and thus enhance their reproduction, they can be considered mutualists. However, if the beetles damage the cycad flowers or consume too much pollen, they may be considered parasites. The other options - the extent to which the beetles are affected by neurotoxins, whether they damage the cycad flowers or the distance they travel between microsporophylls and megasporophylls - are not directly relevant to determining whether the beetles are mutualists or parasites.

Quiz 30: Plant Diversity II: The Evolution of Seed Plants