AP Biology : Plant Structures

Study concepts, example questions & explanations for AP Biology

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Example Questions

Example Question #7 : Understanding Leaves

Which of the following terms is best defined as the microscopic pores on the leaf?

Possible Answers:

Thylakoids

Stomata

Stroma

Chlorophyll

Correct answer:

Stomata

Explanation:

Stomata are the pores on the leaves that allow for carbon dioxide to enter and oxygen to leave the leaf. Stroma, thylakoids, and chlorophyll are all components of the chloroplasts.

Example Question #3 : Macrostructures

Which of the following is a method plants use to attract potential pollinators?

Possible Answers:

Production of nectar in its flowers

Production of a foul or sweet odor

Formation of bright or colorful flowers

All of these

Correct answer:

All of these

Explanation:

Attracting pollinators is key for many plants' success. There are a variety of strategies plants use such as the creation of nectar or odor as well as bright colors to attract pollinators. Also, some plants have ultraviolet patterns on their flowers to direct animals toward their nectar to facilitate pollination.

Example Question #4 : Macrostructures

What strategies might a plant use to disperse its seeds?

Possible Answers:

The seeds may float and be carried by rain or streams

All of these

The seeds may survive animal digestion and be relocated when the animal defecates

The seeds may be blown by the wind

Correct answer:

All of these

Explanation:

Seed dispersal is key to plant success and plants use a wide variety of strategies to facilitate this process. Plants use all the listed strategies in order to spread their seeds. They also make seeds with adhesive properties that stick to animals that pass by. The seeds are then brushed off some time later at a different location. 

Example Question #1 : Understanding Seeds, Flowers, And Fruits

Which of the following are not a part of a flower?

Possible Answers:

Ovary

Leaf

Petal

Anther

Stigma

Correct answer:

Leaf

Explanation:

Leaves are the sites of photosynthesis. Petals are specialized leaves that help attract pollinators. The stigma collects pollen, and facilitates its passage down the style to the ovary to fertilize the ovules (eggs). Anthers produce pollen. The ovary contains a collection of 1 or more ovules.

Example Question #2 : Understanding Seeds, Flowers, And Fruits

A fruit develops from the __________ of a flower.

Possible Answers:

anther

pedicel

stamen

ovary

stigma

Correct answer:

ovary

Explanation:

Once a plant is fertilized, the ovary will ripen around the developing seed of a plant and become a fruit. These fruits perform many functions including protection, provision of nutrients for the developing plant embryo, and aid in dispersal. The pedicel is the stem that connects the flower to the rest of the plant. The stigma is the sticky tip of the pistil that receives pollen from the environment. The stamen is the male section of the flower and the anther is the tip of the stamen that disperses pollen.

Example Question #3 : Understanding Seeds, Flowers, And Fruits

The primary function of the stamen is to __________.

Possible Answers:

protect the developing bud of a flower

attract pollinators

receive pollen in order to fertilize the ovule

produce and distribute pollen

collect water and nutrients from the soil

Correct answer:

produce and distribute pollen

Explanation:

The stamen is the male part of the flower which produces and distributes pollen. The female part of the flower is called the pistil and it receives pollen in order to fertilize the ovule. Roots are the structures that collect water and nutrients from the soil. Colorful petals and sugar-rich nectar are among the objects that are used are used to attract pollinators. Sepals are the leaf-like structures that protect the developing bud of a flower.

Example Question #4 : Understanding Seeds, Flowers, And Fruits

Which of the following is not a function of the flower in angiosperms?

Possible Answers:

Attract pollinators

House reproductive structures

Facilitate pollination

Flowers repel predators

Correct answer:

Flowers repel predators

Explanation:

Flowers are important structures in angiosperms that facilitate reproduction. They do this by housing reproductive structures, attracting pollinators, and providing a space that permits pollination.

Example Question #1 : Understanding Xylem And Phloem

Which of the following is false?

Possible Answers:

Phloem is dead at maturity, while xylem is living

All of these statements are true

Phloem consists of sieve tubes and companion cells, while xylem consists of tracheids and vessel elements

Phloem can transport material bidirectionally, while xylem can only transport material unidirectionally

Phloem is responsible for food transfer, while xylem is responsible for water transfer

Correct answer:

Phloem is dead at maturity, while xylem is living

Explanation:

Xylem is dead at maturity, while phloem is living. All other answer choices are true. Xylem is also thicker and more rigid, which allows for greater pressure during water transport. It provides a strong support structure for the plant, enabling taller growth.

Example Question #2 : Understanding Xylem And Phloem

Which of the following are true regarding phloem?

I. It transports water from the roots to the leaves.

II. It transports sucrose from the leaves to the roots.

III. It is located lateral to xylem in tree stems.

Possible Answers:

II only

I and III

II and III

I only

I and II

Correct answer:

II and III

Explanation:

Phloem is located in the bark of trees and transports sugars (such as sucrose) and organic compounds to the rest of the plant from the leaves. The other plant vascular tissue is xylem. Xylem is located outer wood of trees, and transports water from the roots to the leaves of trees.

Example Question #1 : Understanding Xylem And Phloem

The primary function of xylem is __________.

Possible Answers:

To attract pollinators

To transport water from the roots to the leaves

To perform photosynthesis

To allow exchange of gasses such as carbon dioxide

To transport sugar throughout the plant

Correct answer:

To transport water from the roots to the leaves

Explanation:

Xylem transports water from the roots of a plant to the leaves. It does so through a passive process, negative water pressure created by transpiration in the leaves pulls water up from the roots through the xylem, similar to the action water moving up a paper towel when one corner of a  paper towel is placed in a pool of water. Xylem cells are dead at maturity so they cannot perform photosynthesis. Sugars are transported by phloem (from the leaves to other areas of the plant). Stomata are structures that facilitate gas exchange.

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