BIO182 flowers and fruits amplifire

Which of the following is a conifer?

The common juniper, longleaf pine, European larch, and sequoia are all conifers. Phylum Coniferophyta, the largest gymnosperm phylum, consists of about 600 species of conifers (from the Latin conus, "cone"; ferre, "to carry"), including many large trees. Most species have woody cones, but a few have fleshy cones. Some, such as pines, have needlelike leaves. Others, such as redwoods, have scalelike leaves. Some species dominate vast northern forests, whereas others are native to the Southern Hemisphere. Most conifers are evergreens, which retain their leaves throughout the year.

A bright pink flower with deep floral tubes will most likely be pollinated by which mechanism?

A bright pink flower with deep floral tubes will most likely be pollinated by birds with long beaks. Flowers such as the one in mentioned in this example could have coevolved with nectar-feeding birds. Only birds with long beaks can feed on the plant's nectar. Meanwhile, pollen becomes attached to the top of the bird's head, from which it is transported to other flowers as the bird continues to feed. It is incorrect to say that a bright pink flower with deep floral tubes will most likely be pollinated by bats, honeybees, wind, or by self-pollination. Flowers that are pollinated by nocturnal animals such as bats are usually light-colored and highly fragrant; a bat may not be able to access the nectar contained in a long floral tube. Insects such as honeybees most likely wouldn't have access to the nectar contained in long floral tubes. Finally, plants that spend large amounts of energy producing flowers would not be wind-pollinated or self-pollinated.

Which of the following is not a gymnosperm?

A coconut palm is not a gymnosperm. It is an angiosperm. Extant seed plants form two sister clades: gymnosperms and angiosperms. Gymnosperms have "naked" seeds exposed on modified leaves (sporophylls) that usually form cones (strobili). Gymnosperm phyla include Cycadophyta, Gnetophyta, and Coniferophyta. Douglas fir, sequoia, Ginkgo, and Ephedra are all gymnosperms. Angiosperms are flowering plants with seeds enclosed in chambers that mature into fruits (including beans, grains, and nuts).

Which of the following is enclosed within the pollen wall of a pollen grain?

A male gametophyte is enclosed within the pollen wall of a pollen grain. Sporopollenin in the pollen wall protects the male gametophyte in the pollen grain as it is transported by wind or by hitchhiking on an animal. The transfer of pollen to the part of a seed plant that contains the ovules is called pollination. Following pollination, the male gametophyte develops a pollen tube that discharges sperm to fertilize the egg, which will develop into the sporophyte embryo. The microsporangium is the structure of the sporophyte that produces the microspores that develop into the pollen grains. The megasporangium is the structure of the sporophyte that produces the megaspore. Seed plants retain the megasporangium within the parent sporophyte, where it produces the megaspore. The whole structure of the megasporangium, megaspore, and their integument(s) is called an ovule. Protected inside each ovule, a female gametophyte develops from the megaspore and produces one or more eggs.

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

A pea pod is formed from an ovary. A pea inside the pod is formed from an ovule. A pod is a fruit, and a fruit develops from an ovary. The pea develops from an ovule surrounding a zygote and its food supply. It is incorrect to say that the pod develops from an ovule and a pea develops from a carpel. An ovule contains the female gametophyte and develops into the seed coat—not into the pea pod—and only a portion of the carpel is involved in the formation of the pea and pea pod. It is incorrect to say that a pea develops from a pollen grain. Pollen grains, which simply carry the male gamete, would not develop into peas. It is incorrect to say that the pod develops from an anther. The anther houses sporangia, which give rise to the male gametophyte. Finally, it is incorrect to say that the pod develops from an endosperm and a pea develops from an ovary. The endosperm is a food source found within a seed, and the ovary develops into the pod, not into the pea.

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

A plant is said to be cross-pollinated if pollen grains are transferred to a flower on a different plant. Wind can result in either self-pollination or cross-pollination, so it is not the best answer choice. Both self- and cross-pollination can result from insects. Cross-pollination does not mean the pollen came from a different species of plant; for cross-pollination to occur, the pollen must be from a plant of the same species. Finally, cross-pollination does not mean pollen grains are transferred from a different flower on the same plant; this is self-pollination.

Which of the following is not a trait characteristic of monocots?

A taproot is not a trait characteristic of monocots. Until the late 1990s, most systematists divided flowering plants into two groups, based partly on the number of cotyledons, or seed leaves, in the embryo. Species with one cotyledon were called monocots, and those with two were called dicots. Recent DNA studies, however, indicate that the species traditionally called dicots, are paraphyletic, while others have been placed in the eudicot group. The monophyletic monocots are characterized as having a fibrous root system, parallel leaf venation, a pollen grain with one opening, and floral organs in multiples of three.

Which of the following is not an advantage seeds provide over spores?

Asexual reproduction is not an advantage seeds provide over spores. Spores provide a means of asexually producing and dispersing offspring. Production of a seed requires sexual reproduction. Spores are usually single-celled, whereas seeds are multicellular. The multicellular seed consists of an embryo protected by a layer of integument, the seed coat. A seed can remain dormant for days, months, or even years after being released from the parent plant, whereas most spores have shorter lifetimes. Also, unlike spores, seeds have a supply of stored food. If conditions are favorable where it lands, the seed can emerge from dormancy and germinate, with its stored food providing critical support for growth as the sporophyte embryo emerges as a seedling.

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

Besides the plant tissue that humans ingest, the angiosperm tissue most directly important for human survival is xylem. Xylem is the primary component of wood, which is so important for providing shelter to a large proportion of the human population. It is incorrect to say that besides the plant tissue that humans ingest, the angiosperm tissue most directly important for human survival is phloem, sepals, bark, or cones. Although phloem is a component of wood, this is not the best answer. Bark is used for mulch and to make paper, but these are not crucial to human survival. Cones are not produced in angiosperms. Sepals are not crucial to human survival.

Which of the following is a trait possessed by all angiosperms?

Double fertilization is a trait possessed by all angiosperms. Following pollination, the male gametophyte produces and discharges two sperm cells into the female gametophyte (embryo sac). One sperm fertilizes the egg, forming a diploid zygote. The other sperm fuses with the two nuclei in the large central cell of the female gametophyte, producing a triploid cell. This type of double fertilization, in which one fertilization event produces a zygote and the other produces a triploid cell, is unique to angiosperms. After double fertilization, the ovule matures into a seed. The zygote develops into a sporophyte embryo, and the triploid central cell of the female gametophyte develops into endosperm, tissue rich in starch and other food reserves that nourish the developing embryo. The gametophytes of all seed plants, including angiosperms, are greatly reduced and dependent on the sporophyte. Within the seed plants, gymnosperms, but not angiosperms, produce seeds in ovulate cones. Angiosperms possess flowers, but not all of them are pollinated by animals. Angiosperms possess seeds within fruits, but not all of them are dispersed by animals.

Dietary supplements and decongestants containing ephedrine have recently become more strongly regulated in the United States. Ephedrine is an extract of a plant belonging to which phylum?

Ephedrine—used in dietary supplements and decongestants—is an extract of plants belonging to phylum Gnetophyta. Gnetophyta consists of three genera: Gnetum, Ephedra, and Welwitschia; ephedrine is a compound produced by members of the genus Ephedra. Phylum Anthophyta, phylum Coniferophyta, phylum Ginkgophyta, and phylum Cycadophyta are incorrect.

In addition to seeds, what is a trait unique to seed plants?

In addition to seeds, pollen is a trait unique to seed plants. The evolutionary trend of gametophyte reduction in seedless vascular plants continued further in the seed plants. Although the gametophytes of seedless vascular plants are visible to the naked eye, the gametophytes of most seed plants are microscopic. A pollen grain consists of a male gametophyte enclosed within the pollen wall. The pollen wall protects the pollen grain as it is transported by wind or by hitchhiking on an animal to the female gametophyte, also miniaturized and protected within the megasporangium of the sporophyte. A few species of seedless plants exhibit heterospory, producing two kinds of spores. All land plants have sporangia that produce spores. Nonvascular plants and vascular plants other than seed plants use wind as a means of dispersing spores. Phloem, along with xylem, is vascular tissue present in all vascular plants.

In flowers, pollen is produced in the __________.

In flowers, pollen is produced in the anther. There are two types of fertile floral organs that produce spores, the stamens and the carpels. Stamens produce microspores that develop into pollen grains containing male gametophytes. A stamen consists of a stalk called the filament and a terminal sac, the anther, where pollen is produced. At the tip of the carpel is the sticky stigma that receives pollen. A style leads from the stigma to a structure at the base of the carpel, the ovary, which contains one or more ovules. The sepals are modified leaves at the base of a flower that enclose the flower before it opens. Interior to the sepals are the petals, which are brightly colored in most flowers and aid in attracting pollinators.

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

In gymnosperms, the seed coat develops from the integument. In angiosperms, the seed coat develops from the integuments. The embryo and its food supply are enclosed by a seed coat formed from the two integuments of the ovule. It is incorrect to say that in angiosperms, the seed coat develops from the ovary wall, receptacle, endosperm, or female gametophyte. The ovary wall gives rise to the pericarp. The receptacle is part of the flower stem. The endosperm is a nutritive tissue for the developing embryo.

The diploid generation of the plant life cycle always __________.

The diploid generation of the plant life cycle always produces spores. It is incorrect to say that the diploid generation is called the gametophyte; the gametophyte is the haploid generation. Although mosses and bryophytes have a haploid stage that is larger and more conspicuous than the diploid stage, this is not true for other types of plants. The diploid generation of a plant life cycle does not produce gametes: eggs and sperm. Eggs and sperm are produced by gametophytes during the haploid phase.

In which phylum is the organism thought to be the world's oldest living tree?

The organism thought to be the world's oldest tree is in the phylum Coniferophyta. The bristlecone pine (Pinuslongaeva), which is found in the White Mountains of California, includes some of the oldest living organisms, which reach ages of more than 4,600 years. One tree is called Methuselah because it may be the world's oldest living tree. To protect the tree, scientists keep its location a secret. The Gnetophyta includes only one species, Welwitschia mirabilis, which is found in the deserts of southwestern Africa. Although not as long-lived as the bristlecone pine, it can also live for thousands of years, and its straplike leaves are among the largest leaves known.

The pollen of conifers is primarily dispersed by __________.

The pollen of conifers is primarily dispersed by wind. The conifers are the cone-bearing gymnosperms such as pines, firs, and redwoods. Pollen cones produce haploid microspores that develop into pollen grains, each containing a male gametophyte, which produces sperm. These pollen grains must reach the ovulate cones in order to fertilize the egg that develops from the megaspore retained in the cone. The yellow pollen of conifers is released in large amounts, dusting everything in its path, so that some pollen grains reach their target. In many angiosperm species, animals transfer pollen from one flower to the sex organs of another flower, which makes pollination more straightforward than the wind-dependent pollination of most gymnosperms. The flower is a unique angiosperm structure because it is specialized for mutualisms with insects, birds, bats, or other animals that facilitate sexual reproduction.

The pore in the integuments of an angiosperm ovule through which sperm is delivered is the __________.

The pore in the integuments of an angiosperm ovule through which sperm is delivered is the micropyle. Of the two sperm that are discharged through the micropyle, one sperm fertilizes the egg, forming a diploid zygote. The other sperm fuses with the two nuclei in the large central cell of the female gametophyte, producing a triploid cell that will develop into endosperm to nourish the developing embryo. The pollen tube is the structure produced from the pollen grain to deliver the sperm through the micropyle. The stigma is the sticky tip of a flower's carpel that receives pollen. The embryo sac is another name for the female gametophyte within the ovule. The sepals are the modified leaves at the base of a flower that enclose the flower before it opens.

Which of the following best describes the function of fruits?

The primary function of fruits is the protection and dispersal of seeds. When seeds develop from ovules, the ovary of a flower develops into a fruit, which protects the enclosed seeds and aids in their dispersal by wind or animals; thus, "protection and dispersal of seeds" is the correct answer. Fruit is not a reward for pollinators. Nectar, for example, rewards pollinators; fruit production is a result of successful pollination, but it usually occurs much later. Plants do not use fruit for the storage of food. Because it takes a lot of energy to maintain fruits, they usually drop from the plant before winter. Plants do not use fruit to distract herbivores from eating the leaves; fruit serves only to protect seeds and help with their dispersal—often by attracting herbivores.

The seed coat's most important function is to provide protection for the __________.

The seed coat's most important function is to provide protection for the sporophyte embryo. A seed consists of the seed coat (derived from sporophyte tissue called the integument) surrounding the spore wall, a food supply for the embryo, and the embryo. Seed plants retain the megasporangium within the parent sporophyte, where it is protected by the integument. The megaspore is produced by the megasporangium and remains protected within it. The whole structure—megasporangium, megaspore, and their integument(s)—is called an ovule. Protected inside each ovule, a female gametophyte develops from the megaspore and produces one or more eggs. A male gametophyte arrives protected in a pollen grain with a wall of sporopollenin. The male gametophyte develops a pollen tube that discharges sperm to fertilize the egg, which will develop into the sporophyte embryo and initiate the transformation of the ovule into a seed.

In which group is the sporophyte stage dominant in the alternation of generations?

The sporophyte stage is dominant in the alternation of generations in all vascular plants. Mosses and other bryophytes have life cycles dominated by gametophytes, whereas ferns and other seedless vascular plants have sporophyte-dominated life cycles. The evolutionary trend of gametophyte reduction continued further in the vascular plant lineage that led to seed plants. Although the gametophytes of seedless vascular plants are visible to the naked eye, the gametophytes of most seed plants are microscopic.

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

There is a difference in how reproduction occurs in gymnosperms compared to angiosperms: Only the sperm of angiosperms combine with two central cell nuclei to form a triploid endosperm. The endosperm serves as the nutrient source for the developing embryo. All of the other answer choices are incorrect; they are all characteristics common to both gymnosperms and angiosperms. Both angiosperms and gymnosperms have pollen grains that form pollen tubes. It's incorrect to say that double fertilization only occurs in gymnosperms. Double fertilization is more prevalent in angiosperms. In angiosperms, one sperm fertilizes the egg and another fuses with two nuclei, forming endosperm. However, in some gymnosperms, double fertilization results in two embryos. It is also incorrect to say that only gymnosperms can contain male and female sporangia on the same plant. Most angiosperms contain male and female sporangia within the same flower. Finally, it is incorrect to say that only angiosperms have reduced gametophytes; this is a trait of all seed plants.

Six major crops—wheat, rice, maize, potatoes, cassava, and sweet potatoes—constitute what percentage of all the calories consumed by humans?

Wheat, rice, maize, potatoes, cassava, and sweet potatoes constitute 80% of all the calories consumed by humans.