Chaptere 38 Flashcards

1) Which of the following is the correct order of floral organs from the outside to the inside of a complete flower?
A) petals → sepals → stamens → carpels
B) sepals → stamens → petals → carpels
C) spores → gametes → zygote → embryo
D) sepals → petals → stamens → carpels

2) Arrange the following structures from largest to smallest, assuming that they belong to two generations of the same angiosperm.
1. ovary
2. ovule
3. egg
4. carpel
5. embryo sac
A) 4, 2, 1, 5, 3
B) 5, 4, 3, 1, 2
C) 5, 1, 4, 2, 3
D) 4, 1, 2, 5, 3

3) A summer occupation in the Corn Belt states is de-tasseling the corn: removing unwanted male flowers so that female flowers on the same plant are pollinated by the desired pollen for the hybrid corn. What does this tell you about corn? The flowers are _____.
A) perfect and the plant is dioecious
B) perfect and the plant is monoecious
C) imperfect and the plant is dioecious
D) imperfect and the plant is monoecious

4) During the alternation of generations in plants, _____.
A) meiosis produces gametes
B) mitosis produces gametes
C) fertilization produces spores
D) fertilization produces gametes

5) Which of these is a major trend in land plant evolution?
A) the trend toward smaller size
B) the trend toward a gametophyte-dominated life cycle
C) the trend toward a sporophyte-dominated life cycle
D) the trend toward larger gametophytes

6) Retaining the zygote on the living gametophyte of land plants _____.
A) protects the zygote from herbivores
B) evolved concurrently with pollen
C) helps in dispersal of the zygote
D) allows it to be nourished by the parent plant

7) Sperm cells are formed in plants by _____.
A) meiosis in pollen grains
B) meiosis in anthers
C) mitosis in male gametophyte
D) mitosis in the micropyle

8) A researcher has developed two stains for use with seed plants. One stains sporophyte tissue blue; the other stains gametophyte tissue red. If the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur?
A) The pollen grains will be pure red.
B) The pollen grains will be pure blue.
C) The pollen grains will have red interiors and blue exteriors.
D) The pollen grains will have blue interiors and red exteriors.

9) In which of the following pairs are the two terms equivalent?
A) ovule — egg
B) embryo sac — female gametophyte
C) seed — zygote
D) microspore — pollen grain

10) 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?
A) mitosis
B) meiosis
C) mitosis without subsequent cytokinesis
D) meiosis without subsequent cytokinesis

11) Which of the following statements regarding flowering plants is correct?
A) The gametophyte is the dominant generation.
B) Female gametophytes develop from megaspores within the anthers.
C) Pollination is the delivery of pollen to the stigma of a carpel.
D) The food-storing endosperm is derived from the cell that contains one polar nucleus and two sperm nuclei.

12) In a typical angiosperm, what is the sequence of structures encountered by the tip of a growing pollen tube on its way to the egg?
1. micropyle
2. style
3. ovary
4. stigma
A) 4 →? 2 → 3 → 1
B) 4 → 3 → 2 → 1
C) 1 → 3 → 4 → 2
D) 3 → 2 → 4 → 1

13) If an ovary contains 50 ovules, what is the minimum number of pollen grains that must land to form 50 mature seeds?
A) 25
B) 50
C) 100
D) 500

14) Double fertilization means that _____.
A) flowers must be pollinated twice to yield fruits and seeds
B) one sperm is needed to fertilize the egg, and a second sperm is needed to fertilize the polar nuclei
C) the egg of the embryo sac is diploid
D) every sperm has two nuclei

15) What is typically the result of double fertilization in angiosperms?
A) The endosperm develops into a diploid nutrient tissue.
B) A triploid zygote is formed.
C) Both a diploid embryo and triploid endosperm are formed.
D) Two embryos develop in every seed.

16) Suppose that 100 pollen grains land on a stigma, and 50 mature seeds are formed in the fruit. What does this indicate about the pollination process and success?
A) 50% success: 100 pollen grains grew to 50 ovules, and double fertilization occurred.
B) 50% success: evidently, only 50 sperm pollinated 50 anthers.
C) 50% success: 50 sperm fertilized 50 eggs, and 50 sperm fused with 50 polar nuclei.
D) 50% success: 50 sperm fertilized 50 eggs, and 50 sperm fused with 100 polar nuclei.

17) Which of the following flower parts develops into a seed?
A) ovule
B) ovary
C) stamen
D) carpel

18) The vast number and variety of flower species is probably related to various kinds of _____.
A) seed dispersal agents
B) pollinators
C) herbivores
D) climatic conditions

19) It is estimated that animal-pollinated or insect-pollinated plants produce 1000 pollen grains for each ovule; wind-pollinated plants produce 1,000,000 pollen grains for each ovule. What does that indicate about pollination systems?
A) Wind-pollinated plants rarely produce seeds.
B) Wind pollination is more efficient than animal-assisted pollination.
C) Wind pollination is less efficient than animal-assisted pollination.
D) Wind pollination is costlier to the plant than animal-assisted pollination.

20) Cottonwood, aspen, and willow trees have beige flowers, with no petals, that appear before the tree's leaves are out in the spring; and they are dioecious. What does this indicate about these trees?
A) Their insect pollinators are specialists.
B) Early emerging insects are probably the pollinators.
C) Their pollen is dispersed by wind.
D) The trees are self-pollinating.

21) Which of the following occur during the formation of an embryo from a zygote in angiosperms?
I) The root and shoot systems emerge from the seed.
II) Basal cells form a connection between the parent plant and the developing embryo.
III) Meiosis produces a mass of cells that become the young embryo.
IV) Cells differentiate to form the basic plant tissue types.
V) The early root-shoot axis is formed.
A) I, II, and III
B) II, IV, and V
C) II, III, IV, and V
D) III, IV, and V

22) The egg of a plant has a haploid chromosome number of 12 (n = 12). What is true about the number of chromosomes in the cells of other tissues of this plant?
A) The sperm has 6 chromosomes.
B) The leaves and stems have 12 chromosomes.
C) The zygote has 12 chromosomes.
D) The endosperm has 36 chromosomes.

23) 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?
1. The exterior of the seed coat should have barbs or hooks.
2. The seed coat should contain secondary compounds that irritate the lining of the animal's mouth.
3. The seed coat should be able to withstand low pHs.
4. The seed coat, upon its complete digestion, should provide vitamins or nutrients to animals.
5. The seed coat should be resistant to the animals' digestive enzymes.
A) 4 only
B) 1 and 2
C) 3 and 5
D) 3, 4, and 5

24) Which of these events occurs first in seed germination?
A) Cell division occurs in the embryo and growth starts.
B) Mitochondria multiply and provide energy for growth processes.
C) Water is taken up.
D) Oxygen is produced and proteins are synthesized.

25) Before plowing a field, a farmer thought the bare field looked weed-free. Three days after plowing and turning over the soil, he was amazed to see thousands of tiny seedlings. What is the most likely reason for the mass germination of seeds?
A) large seeds that needed soil disturbance to germinate
B) small seeds that need light to germinate
C) small seeds that were scarified by exposure to plow
D) large seeds that needed exposure to higher levels of oxygen to germinate

26) Angiosperms are the most successful terrestrial plants. Which of the following features is unique to them and helps account for their success?
A) wind pollination
B) dominant gametophytes
C) fruits enclosing seeds
D) sperm cells without flagella

27) Which of the following flower parts develops into the pulp of a fleshy fruit?
A) stigma
B) style
C) ovule
D) ovary

28) The black dots that cover strawberries are actually individual fruits. The fleshy and tasty portion of a strawberry derives from the receptacle of a flower with many separate carpels. Therefore, a strawberry is _____.
A) both a multiple fruit and an aggregate fruit
B) both a multiple fruit and an accessory fruit
C) both an aggregate fruit and an accessory fruit
D) a simple fruit with many seeds

29) 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) true?
1. The flowers that gave rise to such pods were not pollinated.
2. Pollen tubes did not enter all of the ovules in such pods.
3. There was apparently not enough endosperm to distribute to all of the ovules in such pods.
4. The ovules that failed to develop into seeds were derived from sterile floral parts.
5. Fruit can develop, even if all ovules within have not been fertilized.
A) 1 only
B) 1 and 5
C) 2 and 5
D) 3 and 5

30) Unripe fruits protect seeds from predation and early germination. What is the major function of ripe fruits?
A) attracting pollinators
B) dispersing seed
C) releasing nutrients to seeds
D) keeping the seed hydrated before germination

Use the following information to answer the question(s) below.
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, 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.
31) 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?
1. double fertilization
2. pollen tube emerges from pollen grain
3. pollen tube enters micropyle
4. pollination
A) 4, 2, 3, 1
B) 4, 3, 2, 1
C) 2, 4, 3, 1
D) 2, 4, 1, 3

Use the following information to answer the question(s) below.
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, 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.

32) Orchid bees are to Brazil nut trees as ________ are to pine trees.
A) breezes
B) rain droplets
C) seed-eating birds
D) squirrels

33) 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?
A) poor sporophyte fertility
B) failure to produce fertile ovules
C) failure to produce pollen
D) pollination failure

34) The same bees that pollinate the flowers of the Brazil nut trees also pollinate orchids, which are epiphytes (in other words, plants that grow on other plants); however, orchids cannot grow on Brazil nut trees. These observations explain _____.
A) the coevolution of Brazil nut trees and orchids
B) why Brazil nut trees do not set fruit in monoculture plantations
C) why male orchid bees do not pollinate Brazil nut tree flowers
D) why male orchid bees are smaller than female orchid bees

35) The agouti is most directly involved with the Brazil nut tree's dispersal of _____.
A) male gametophytes
B) female gametophytes
C) sporophyte embryos
D) sporophyte megaspores

36) Animals that consume Brazil nuts derive nutrition mostly from tissue whose nuclei have how many chromosomes?
A) 17
B) 34
C) 51
D) 68

37) Which of the following could be considered an evolutionary advantage of asexual reproduction in plants?
A) increased success of progeny in a stable environment.
B) increased agricultural productivity in a rapidly changing environment.
C) maintenance and expansion of a large genome.
D) increased ability to adapt to a change in the environment.

38) Plants produce more seeds when they reproduce asexually than sexually. Yet most plants reproduce sexually in nature. What is the probable explanation for the prevalence of sexual reproduction? Sexual reproduction _____.
A) is more energy efficient than asexual reproduction
B) ensures genetic continuity from parents to offspring
C) mixes up alleles contributing to variation in a species
D) is not dependent on other agents of pollination

39) Which of the following is a true statement about asexual reproduction in plants?
A) Clones of plants do not occur naturally.
B) Cloning, although achieved in animals, has not been demonstrated in plants.
C) Making cuttings of ornamental plants is a form of fragmentation.
D) Reproduction of plants by cloning may be either sexual or asexual.

40) While looking at a flower in your garden, you notice that it has carpels with very long styles, and stamens with very short filaments. This plant is most likely to reproduce by _____.
A) cross-pollination
B) selfing
C) asexual reproduction

41) Which of the following types of plants are incapable of self-pollination?
A) dioecious
B) monoecious
C) wind-pollinated
D) insect-pollinated

42) Which of the following is a potential advantage of introducing apomixis into hybrid crop species?
A) Cultivars would be better able to cope with a rapidly changing environment.
B) They would have a larger potential genome than inbred crops.
C) All of the desirable traits of the cultivar would be passed on to offspring.
D) They would benefit from positive mutations in their DNA.

43) Pollen from a plant with the S1S2 genotype is recognized and allowed to germinate on the stigma of the same plant with the S1S2 genotype. According to the S-system hypothesis, this indicates that the plant is _____.
A) self-compatible and can self-pollinate.
B) self-compatible and must cross-pollinate.
C) self-incompatible and can self-pollinate.
D) self-incompatible and must cross-pollinate.

44) Over human history, which process has been most important in improving the features of plants that have long been used by humans as staple foods?
A) genetic engineering
B) artificial selection
C) sexual selection
D) pesticide and herbicide application

45) Which of these activities is part of the development of crop plants from wild relatives?
I) people planting seeds of the plants with the characteristic wanted
II) people making observations of desired plant characteristics
III) people eating products from only the plants with desired characteristics
IV) people developing several varieties of crops from a wild relative
A) I and II
B) I and IV
C) I, III, and IV
D) I, II, and IV

46) Regardless of where in the world a vineyard is located, for the winery to produce a Burgundy, it must use varietal grapes that originated in Burgundy, France. The most effective way for a new California grower to plant a vineyard to produce Burgundy is to _____.
A) plant seeds obtained from French varietal Burgundy grapes
B) transplant varietal Burgundy plants from France
C) acquire a tissue culture of varietal Burgundy grapes from France
D) graft varietal Burgundy grape scions onto native (Californian) root stocks

47) The most immediate potential benefits of introducing genetically modified crops include _____.
I) creating crops that can grow on land previously unsuitable for agriculture
II) creating crops with better potential for biofuel production
III) creating crops with better nutritional attributes
IV) increasing crop yield
V) decreasing the mutation rate of certain genes
A) only II, III, and IV
B) only I, II, III, and IV
C) only III, IV, and V
D) I, II, III, IV, and V

48) "Golden Rice" _____.
A) is resistant to various herbicides, making it practical to weed rice fields with those herbicides
B) includes bacterial genes that produce a toxin that reduces damage from insect pests
C) produces larger, golden grains that increase crop yields
D) contains daffodil genes that increase vitamin A content

49) Which of the following is a scientific concern related to creating genetically modified crops?
A) Herbicide resistance may spread to weedy species.
B) Genetically modified crops cannot survive without the addition of great amounts of fertilizer to the soil.
C) The monetary costs of growing genetically modified plants are significantly greater than traditional breeding techniques.
D) Genetically modified plants are less stable and may revert back to parental genotypes.

50) Which of the following would be the most problematic for the natural environment in the development of genetically engineered crops?
A) the introduction of male sterility into crops
B) the creation of transgenic crops with apomictic seeds
C) the creation of crops with flowers that develop normally, but fail to open
D) the creation of transgenic crops that hybridize more easily

51) Fruit ripening represents an example of positive feedback. Which one of the following statements accurately justifies why the process of fruit ripening involves positive feedback?
A) Once seeds have reached maturity, chemical signals increase enzymatic activity in fruit to convert sugars into starches, thicken pulp, and maintain color in the fruit.
B) Once seeds have reached maturity, chemical signals block enzymatic steps that normally convert sugars into starches and sugars accumulate from photosynthetic activity within the fruit.
C) Chemical signals initiate a process that triggers enzymatic activity, which involves converting starches into sugars, softening of pulp, and color change of fruit.
D) Chemical signals shut down enzymatic activity within the fruit, which results in breakdown of starches into sugars, softening of pulp, and color change of fruit.

52) In order for an ovule (egg cell) in a flower to be fertilized and form a viable seed, pollination must occur. In this process, a sperm cell is delivered to the ovule when the pollen grain lands on the stigma and grows a tube, which enters the ovary and discharges the sperm cell to form a diploid zygote when it fuses with the egg cell. Although it only takes one pollen grain to successfully deliver sperm to the egg, numerous pollen grains are generally transferred to the stigma during insect pollination of flowering plants. Which phenotypic traits of pollen would you predict to be selected upon to promote survival and fitness within an insect-pollinated flowering plant?
A) High pollen tube growth rate and ability to detect chemicals from cells surrounding the egg.
B) Ability to produce the most cells during mitotic growth of the pollen tube.
C) Elaborate and striking UV "nectary guides" on the petals to guide an insect to the stigma.
D) Larger pollen in order to carry the tube that is necessary for delivery of the sperm cells.

53) Many flowering plants coevolve with specific pollinators. The Madagascar orchid has a 12-inch floral tube and is a reliable nectar source for the hawkmoth, which has a correspondingly long proboscis (tongue). Which statement most accurately describes how coevolution might have occurred for the hawkmoth and Madagascar orchid shown here?
A) The hawkmoths that expended the most effort to reach the nectar would be the most fit, and pass the longer tongue phenotype to their offspring.
B) Natural selection would favor orchids with nectar tubes just long enough to for an insect with pollen to make contact. Hawkmoths whose tongue could reach the deep tubes would be more fit.
C) Hawkmoths whose tongue was just long enough to obtain nectar, but not able to pick up pollen would become the most fit in the population.
D) It is most likely that mutations that resulted in both the length of the orchid floral tube and the length of the hawkmoth tongue occurred abruptly and simultaneously.