Biological Science

Scott Freeman, Lizabeth Allison, Michael Black

Chapter 41

Plant Reproduction - all with Video Answers

Educators

Chapter Questions

Problem 1

What is the major evolutionary trend in land plant life cycles?
a. Instead of heing approximately the same size and shape, gametophytes and sporophytes began to look different.
b. Sporophytes became larger and long lived while gametophytes became drastically reduced.
c. In lineages that evolved more recently, such as angiosperms, spores are no longer produced.
d. Sporophytes began to rely on gametophytes for all of their nutritional needs.

John Barone

John Barone

Numerade Educator

Problem 2

What happens when double fertilization occurs?
a. Two zygotes are formed, but only one survives.
b. Two sperm fertilize the egg, forming a triploid zygote.
c. One sperm fertilizes the egg, while another sperm fuses with the polar nuclei
d. One sperm fertilizes the egg, while two other sperm fuse with a polar nucleus.

John Barone

Numerade Educator

Problem 3

What is a fruit?
a. an expanded ovary that includes a seed or seeds
b. a structure consisting of an embryo and a food supply surrounded by a tough coat
c. a female gametophyte
d. a male gametophyte

John Barone

Numerade Educator

Problem 4

Why is the interaction between angiosperms and pollinators considered mutualistic?
a. New species can form if mutant flowers attract new types of pollinators.
b. Flowers may have an array of traits, including corolla shape, color, scent, and the presence of nectar, to attract a specific type of pollinator.
c. Wind pollination is much "cheaper," but animal pollination is much more precise.
d. Angiosperms get their pollen dispersed, while pollinators get food.

John Barone

Numerade Educator

Problem 5

In the angiosperm life cycle, which cells undergo meiosis? Which cells are spores? Which structures are gametophytes?

John Barone

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Problem 6

What events take place during pollination and fertilization?

John Barone

Numerade Educator

Problem 7

Why is the emergence of the radicle an important first step in germination?
a. Its hook helps protect the shoot that emerges later.
b. It carries out photosynthesis to supply the embryo with food.
c. It is important for establishing a supply of water to the growing embryo.
d. It is necessary to break the seed coat.

John Barone

Numerade Educator

Problem 8

In terms of maximizing reproductive success, what is the advantage of asexual reproduction? What is the disadvantage?

John Barone

Numerade Educator

Problem 9

How do the structure and function of sepals and petals differ? How would you expect these structures to differ in species that are pollinated by wind versus bumblebees?

John Barone

Numerade Educator

Problem 10

What are the advantages and disadvantages of self-fertilization versus those of outcrossing?

John Barone

Numerade Educator

Problem 11

Consider a carpel, an ovary, and an ovule. Which is responsible for producing the female gametophyte, and which produces the pericarp of a fruit? Are these structures part of the sporophyte, the gametophyte, or a combination of the two?

John Barone

Numerade Educator

Problem 12

What is the relationship between the endosperm of corn and the cotyledons of beans?

John Barone

Numerade Educator

Problem 13

What happens when outcrossing occurs?
a. Inbred offspring are produced.
b. The same flower can be visited by many different types of pollinators - not a single specialist species.
c. Gametes from different individuals fuse to form a zygote
d. Gametes from the same individual fuse.

John Barone

Numerade Educator

Problem 14

Because wind is less efficient than animals at moving pollen from plant to plant, wind-pollinated plants generate far more pollen than animal-pollinated plants. How much of that pollen is wasted? Consider a typical field-corn plant that makes one ear. Ears contain about 600 kernels, each of which is fertilized by an individual pollen grain. Male flowers clustered in the tassel at the top of the plant release about 10 million pollen grains per plant. Using these numbers, what percentage of corn pollen is wasted?

John Barone

Numerade Educator

Problem 15

Some flowering plants "cheat" their pollinators because they offer no food reward. Likewise, certain pollinators cheat plants by removing nectar from flowers without picking up pollen. (In some cases, they do so by chewing through the petals that hold the store of nectar.) Speculate on the types of mutations that might modify insect behavior and/or plant structure in a way that limits cheating and enforces mutualism.

John Barone

Numerade Educator

Problem 16

Consider the following fruits: an acorn, a cherry, a burr, and a dandelion seed. Based on the structure of each of these fruits, predict how the seed is dispersed. Design a study that would estimate the average distance that each type of seed is dispersed from the parent plant.

John Barone

Numerade Educator