Exam 38: Angiosperm Reproduction and Biotechnology

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 ________.

Sperm cells are formed in plants by ________.

Use the following information to answer the 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, 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. 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 ________.

Some dioecious species have the XY genotype for male and XX for female. After double fertilization, what would be the genotypes of the embryos and endosperm nuclei?

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 ________.

Which of the following would be the most problematic for the natural environment in the development of genetically engineered crops?

Use the following information to answer the 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, 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. Orchid bees are to Brazil nut trees as ________ are to pine trees.

Which of the following pollinating agents is correctly matched with the type of plant it helps pollinate?

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 ________.

Pineapple is a ________ fruit.

Which of the following flower parts develops into the pulp of a fleshy fruit?

The vast number and variety of flower species is probably related to various kinds of ________.

The black dots that cover strawberries are actually fruits formed from the separate carpels of a single flower. The fleshy and tasty portion of a strawberry derives from the receptacle of a flower with many separate carpels. Therefore, a strawberry is

Which of the following could be considered an evolutionary advantage of asexual reproduction in plants?

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?

Which statement concerning grafting is correct?

A typical angiosperm embryo sac (female gametophyte) has ________ cells.

Which of these is a major trend in land plant evolution?

Which of the following is a scientific concern related to creating genetically modified crops?

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.