Exam 40: Plant Reproduction

The sperm and egg each contribute 50% of the nuclear genetic material to the zygote that becomes the embryo and the new plant.Mitochondria and plastids that become chloroplasts are passed primarily from the female parent.What feature of the male or female gametophytes accounts for this?

Angiosperms are unique in having double fertilization that forms endosperm.What is true about double fertilization in angiosperms?

Home flower gardeners in northern latitudes like to grow plants that flower only in the spring or flower only in the late summer and fall.They are planting flowers that are most sensitive to

Pines,including the whitebark pine,are pioneer-type trees,meaning the young seedlings and trees need to grow in open areas with sunlight.Which of these would be most helpful in spreading the seeds of the trees?

A population of flowers varies from deep blue to nearly white.Bees are active during the day and prefer color.Moths are active at night,when colors are not very visible and white is more conspicuous.Design a scenario in which the blue and white flowers form two species where there once was one species.You must end with a conclusion that the two new species cannot interbreed (a definition of a species).

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

Most plants are adept at asexual reproduction.What is the probable explanation for the energy spent for sexual reproduction?

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 kinds of seeds did the plowing help with germination?

A gardener in Canada wants to surprise his mother on her birthday and make her favorite Shrubalthea bush flower in May instead of the end of June.The bush is growing in the greenhouse.Which of the following might make the Shrubalthea bush flower early?

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?

After double fertilization in angiosperms,what development sequence is correct?

How are the life cycles of liverworts and angiosperms alike?

Charles Darwin experimented with reactions of grass seedlings (monocots)relative to applied auxin (a plant hormone)and light.He used the youngest seedlings with a structure that dicots do not have.What is the name of that structure?

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?

Which of these events happens first in nearly all seed germination?

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

What is the similarity between spores and gametes?

Hammer orchids resemble female thyranide wasps and release a chemical signal called pheromone to deceive male thyranide wasps and accomplish pollination.Compared to food-deceiving orchids,is it more or less likely that pollen of the hammer orchid will be transferred to the flower of the same species than to the flower of a different species?

Which of these events occurs first in seed germination?

Plants in crop fields such as corn are genetically very similar.What are benefits of this phenomenon? What are pitfalls of that phenomenon?