28. Plants

The triploid nucleus of the embryo sac develops into the __________.

Seed plants reproduce using pollen, which develops into sperm cells. Which of the following structures is responsible for carrying the male gametes in seed plants?

What can be derived from seed plants?

During pollination, pollen grains are transferred from the __________ to the __________.

Each pollen grain of a gymnosperm contains a __________.

The diploid generation of the plant life cycle always __________.

A pea pod is formed from __________. A pea inside the pod is formed from __________.

Which one of the following is true of seed plants but not true of seedless plants?

In ovulate cones, megasporocytes undergo __________ and produce __________ megaspores.

The portion of a flower that receives the pollen is the __________.

Which of the following best describes the function of fruits?

The vast majority of angiosperms with two cotyledons formerly classified as __________ are now classified as __________.

Six major crops˜wheat, rice, maize, potatoes, cassava, and sweet potatoes˜contribute disproportionately to human diets. What percentage of all the calories consumed by humans is supplied by these crops?

What global change occurring between the Carboniferous period and the Permian period likely contributed to the success of the gymnosperms?

In a typical conifer, how long does it take for fertilization to occur after pollination?