BIO 102 unit 4

Why is staggered maturation a good mechanism for reducing self-fertilization?

By the time one gamete is ready, the other is no longer viable or even present for fertilization to occur.

Which of these hormones or group of hormones is primarily synthesized in the roots and travels to other regions of the plant?

cytokinins

Succulent leaves and stems are associated with plants that live

in very dry climates.

In plants, abscisic acid:

maintains seed dormancy and winter dormancy; closes stomata

Which of the following is the most plausible explanation for why fruits evolved in plants?

to aid in the dispersal of the seeds

How many petals does this flower have?

10

How many pollen sacs are found in each anther on a flowering plant?

4

When you are seven years old, you write your name four feet above the ground, into a 12-foot-tall bamboo plant. You spend the next ten years in a special home for vandals. When you get out the bamboo is 24 feet tall. At that time, how far above the ground will your name be?

4 feet

Which of the following is NOT true about plant hormones?

Abscisic acid generally promotes growth.

Which of the following is not a plant response connected to a tropism?

All of the above are responses related to a tropism.

Which tropism in plants involves the hormone auxin?

All of the above involve auxin in some way.

Which of the following is NOT a method by which plants reduce the possibility of self-fertilization?

All the above are methods used by plants to reduce self-fertilization.

Plant hormones

Answers b), c), and d) are all true about plant hormones.

Which of the following is NOT true about secondary growth seen in trees?

Cells of the vascular cambium produce a ring of cells toward the inside of the trunk called the lateral meristem.

Primary plant growth occurs at the

All of the above are correct.

What is a plausible reason for why cacti and succulents lack leaves?

The surface-area-to-volume ratio is reduced.

Which of the following statements is true about tree growth?

The vascular cambium produces wood.

Which of the following is NOT true about gibberellins?

They are produced by some plant species in order to help them outcompete other species.

Seeds that require extra "processing" before they can germinate may have a competitive advantage for which of the following reasons?

They won't germinate unless they pass through an animal gut and are deposited with "natural fertilizer," insuring the availability of extra nutrients.

In Native American folklore, it was believed that spirits lived within a popcorn kernel. These spirits became angry when the kernel was heated, finally bursting and turning themselves inside-out with a pop. What is the scientific explanation for why popcorn pops?

Water within the kernel turns to steam, blowing the kernel open and exposing the cooked starch.

Flowers or leaves that fold up in response to touch are most likely exhibiting

a mechanical defense.

In plants, the first product of meiosis is

a spore.

Which of the following could be called the "plant stress hormone"?

abscisic acid

hich plant hormone or group of hormones is responsible for bud and seed dormancy?

abscisic acid

Under conditions of impending water shortage, the closing of stomata is regulated in part by:

abscisic acid.

The most striking change that occurs in a germinating seed is that it

absorbs a large amount of water.

Which of the following characteristics do most plants share with land animals?

an embryo that develops within a protected environment

Gravitropism is the tendency of plants to grow upward vertically and for plant roots to grow downward. Which plant hormone is associated with gravitropism?

auxin

Which of the following is not a secondary compound found in plants?

auxin

Which plant hormone causes root branching, shoot elongation, and the promotion of fruit development?

auxin

High concentrations of ______ stimulate root production.

auxins

One difference in the action of auxins and gibberellins is

auxins promote early fruit development while gibberellins promote fruit enlargement.

Cytokinins promote the growth of

axillary buds

The most important cue in setting the biological clock in plants is

cycles of light and dark.

Which plant hormone is noted for initiating new branches from lateral buds and for retarding leaf death?

cytokinins

Which of the following situations would lead to the greatest increase in transpiration?

decreased humidity, increased wind, and increased temperature

Which of the following growth characteristics of an arrowleaf plant matches the habitat in which it is planted?

deep water: long, ribbon-like leaves

Branches form on a plant when

dormant meristem cells in the stem are stimulated by plant hormones.

Meristem cells left behind as the top of a plant grows higher are

dormant.

Which of the following could be called the "fruit-ripening hormone"?

ethylene

The production of the plant hormone _________ plays a major role in _____________.

ethylene; leaf death

The stamens of a flowering plant are broken down into two separate parts. The long, stalk-like structure is the _________ and the pollen-producing bodies on the tips are the __________.

filament; anthers

Carrion flowers mostly attract

flies.

In day-neutral plants,

flower production is triggered by the state of maturity.

In angiosperms, the _______________ are the specialized reproductive organs whose main function is to bring together the sperm and egg.

flowers

Fruits often taste bad before they ripen. This is probably because

fruit that gets dispersed before the seeds are developed may not be capable of propagating new plants

Which plant hormone is responsible for the breakdown and metabolism of the endosperm stored within a germinating seed?

gibberellin

The growth response of a young plant to the pull of gravity is known as

gravitropism.

When gibberellins are added to cabbage plants, they

grow very large leaves.

The embryo sac that forms within the ovule in a plant ovary forms from a

haploid megaspore undergoing mitosis.

Which of the following terms describes the situation in most angiosperm plants, where male and female parts are in the same individual?

hermaphroditic

sexual reproduction enhances the genetic diversity of offspring for three reasons: 1) genetic material from two individuals is mixed; 2) crossing over creates new allele combinations; and 3)

homologues are randomly reassorted.

Unlike animals, which produce each hormones _________________, plants produce hormones _________________.

in a specific part of the body; in many cell types

Which of the following is the correct order of events in the angiosperm lifecycle?

male anthers release pollen, a pollen grain releases two sperm, a sperm fuses with the egg, a sperm fuses with endospore-forming nuclei, the zygote and endosperm develop into a seed

By what process do the haploid cells in a new pollen grain produce two sperm cells?

mitosis

When a meristem tissue divides.

one cell differentiates into plant tissue while the other remains a meristem cell.

Fruit develops from a plant'

ovary.

Seeds germinate only when levels of water, temperature, and _______ are "just right."

oxygen

Plants "know" what time it because plants contain

photosensitive pigments

The knots we see in wood represent

places where branches were connected to the trunk.

Which of the following is NOT a plant hormone?

prolactin

Aspens have adapted to cold temperatures on the Orkney Islands by

reproducing asexually through root suckers.

Poinsettias are examples of

short-day plants.

When grapes are sprayed with gibberellins, they

spread out, so there is more space between grapes in a bunch.

Which of the following describes an alternative to sexual reproduction employed by most plants?

sprouting (such as through root suckers)

The _________ is the pollen-producing part of the male reproductive structure of the flowering plant.

stamen

Some fruits are designed to be attractive food for animals. Other fruits that rely on animal dispersal are

sticky or covered with clingy burrs.

The female parts of a flower are the

stigma, style, ovary, and ovule

"Double fertilization" in angiosperm plants refers to

the fusion of one sperm cell with the egg, and another with two nuclei of the endosperm-forming cell.

Plants sense the season of the year by measuring

the length of night and day.

When gibberellins are sprayed on a plant, regardless of the season, they can cause

the production of flowers.

The outer green leaflike portions of a flower enclose the inner petals like a protective barrier. Can you name this outermost portion from the choices below?

the sepals

What is the structure on a flowering plant that receives the pollen granules?

the stigma

Which type of plant growth occurs as a result of physical touch?

thigmotropism

From an evolutionary standpoint, why do many flowers have attractive colors and smell good?

to facilitate the transport of male gametes to female structures

Each angiosperm pollen grain contains how many sperm cells?

two

Which of the following is a common gardening practice?

using genetically identical clones produced by a plant through asexual reproduction

Seeds that are tiny and light are most likely to be

wind-dispersed.

In angiosperm "double fertilization," one sperm cell fertilizes the central cell while the other fuses with

wo polar nuclei to form a cell that develops into endosperm.

Which of the following is INCORRECT about plant gamete production?

Megaspores divide to produce microspore mother cells.

Experiments with planting cuttings from the same plant into different habitats has revealed that

None of the above are correct.

What is the effect of a short burst of light during a short-day plant's dark period?

The plant will flower because the length of day remained unchanged.