Exam 40: Plant Reproduction

It is estimated that animal- 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?

What is the male gametophyte made of?

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

What is the similarity between spores and gametes?

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 most likely to reproduce by _____.

Use the following information when answering the corresponding question(s). Whitebark pine (Pinus albicaulis)is an important tree at timberline in the Rocky Mountains and Sierra Nevadas.Its large seeds provide food for grizzly bears,squirrels and other rodents,and many birds,including its major seed disperser,the Clark's nutcracker (Nucifraga columbiana).The Clark's nutcracker has a pouch below its tongue for carrying seeds,which it deposits 10 m to 12 km from a tree.Clark's nutcrackers often store many more seeds than they need for survival;in a single year,one bird can store more than 30,000 seeds.They store 3-5 seeds from one cone in each cache and typically use the seeds for food during spring and summer.When these birds do not harvest the seeds,the seeds germinate and form new whitebark pine trees.(D.F.Tomback.1982.Dispersal of whitebark pine seeds by Clark's nutcracker: A mutualism hypothesis.Journal of Animal Ecology 51:451-67. ) -Refer to the paragraph on whitebark pine seed dispersal by Clark's nutcracker.Clark's nutcracker stores seeds in caches.What type of spatial distribution of whitebark pine would you expect to find in an area with a high population of Clark's nutcrackers?

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

It is possible to make seedless tomatoes by removing the anthers of the flower and putting a hormone (auxin)on the stigma of the tomato flower.Weekly applications are required.Over the course of development,the stigma and style fall off,and the ovary develops into a normal-looking tomato with no seeds.Normally,seed and fruit formation are coordinated using hormone signaling.What does the application of auxin indicate?

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?

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

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).

Endosperm is a major part of monocot seeds.In most dicots,_____.

Which of the following correctly identifies the function of the flower part named?

During self-fertilization,which of the following is absent?

How are the life cycles of liverworts and angiosperms alike?

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 _____.

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?

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?

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

Use the following information when answering the corresponding question(s). Whitebark pine (Pinus albicaulis)is an important tree at timberline in the Rocky Mountains and Sierra Nevadas.Its large seeds provide food for grizzly bears,squirrels and other rodents,and many birds,including its major seed disperser,the Clark's nutcracker (Nucifraga columbiana).The Clark's nutcracker has a pouch below its tongue for carrying seeds,which it deposits 10 m to 12 km from a tree.Clark's nutcrackers often store many more seeds than they need for survival;in a single year,one bird can store more than 30,000 seeds.They store 3-5 seeds from one cone in each cache and typically use the seeds for food during spring and summer.When these birds do not harvest the seeds,the seeds germinate and form new whitebark pine trees.(D.F.Tomback.1982.Dispersal of whitebark pine seeds by Clark's nutcracker: A mutualism hypothesis.Journal of Animal Ecology 51:451-67. ) -Refer to the paragraph on whitebark pine seed dispersal by Clark's nutcracker.Pines,including the whitebark pine,are pioneer-type trees.Which disperal conditions would be best for high germination rates and seedling survival?