Exam 38: Angiosperm Reproduction and Biotechnology

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?

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?

In a typical dicot ovule, a surviving megaspore divided by ________ consecutive mitotic divisions without cytokinesis results in ________ nuclei.

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.

Which of the following is an effective method to produce plants exhibiting hybrid vigor?

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 flower parts develops into a seed?

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 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 is correctly paired with its life cycle generation?

During the alternation of generations in plants, ________.

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 this, the plant is ________.

Which of the following statements regarding flowering plants is correct?

Which of these events occurs first in seed germination?

Pineapple is a ________ fruit.

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

A fruit is

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. Animals that consume Brazil nuts derive nutrition mostly from tissue whose nuclei have how many chromosomes?

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

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 ________.