The most primitive flowers are thought to possess which of the following characteristics?
Many spirally arranged partsNumerous stamens and carpels
Which of the following groups is the largest and most diverse phylum in the Plant Kingdom?
Angiosperms
Seeds develop directly from a(n) ______ within a carpel.
ovule
Which of the following statements best distinguishes gymnosperms from angiosperms?
Angiosperms have their ovules and seeds enclosed in a structure.
The Magnoliophyta is divided into two large classes, the _______ (dicots) and the ______ (moncots).
MagnoliopsidaLiliopsida
Most scientists agree that flowers evolved to take advantage of ______.
motile animals in the reproductive process
With over 250,000 known species, the flowering plants, also called the _______ , are the largest and most diverse group in the Plant Kingdom.
angiosperms
Angiosperms get their name based on the fact that they have an inrolled leaf called a ______ , with seeds found along its margins.
carpel
One of the biggest distinctions between angiosperms and gymnosperms is that angiosperms enclose which of the following parts in a structure?
SeedsOvules
All angiosperms are presently considered to belong to the Phylum
Magnoliophyta
Flowering plants are hugely successful because they developed numerous strategies over million of years for ______.
pollination and seed dispersal
Angiosperm ovules are enclosed inside the ovary, which develops into the ______.
fruit
Multiple lines of evidence have led contemporary botanists to believe that angiosperms evolved independently from the ________ , commonly referred to as the "seed ferns.
pteridosperms
Select all of the following that may be growth forms of the phylum Magnoliophyta.
TreesShrubsEpiphytes
In angiosperms, the ovules are enclosed within the
ovary
Modern botanists hypothesize that a flower is really a modified ______.
stem bearing modified leaves
Angiosperms are said to be heterosporous because they produce ______.
two types of spores
The most primitive flowers are thought to have a long receptacle and ______.
many undifferentiated, spirally-arranged parts
Duckweeds are flowering plants that may be as small as 1 ______ long.
millimeter
Like the gymnosperms, the angiosperms produce two types of spores, and therefore are called
heterosporous
The tiny female gametophyte is wholly enclosed in the angiosperm sporophyte, whereas the male gametophyte is reduced to a ______.
pollen grain
After three successive rounds of mitosis in a developing flower bud, the megaspore is many times larger than its original volume, and it contains ______ haploid nuclei.
eight
Angiosperm ovules have two outer layers of _______ , which later in development become the seed coat.
integuments
Synergids are two of the seven cells found in a typical female gametophyte, and they function primarily to ______.
guide the pollen tube to the egg
Match the following types of angiosperm gametophytes to their best description.Instructions
Female gametophyte - Wholly enclosed within sporophyte tissueMale gametophyte - Consists of a pollen grain with three nuclei
Developing anthers contain four patches of cells that contain many diploid ______.
microsporocytes
Starting with a diploid megasporocyte at the top, rank these events in the order that leads to the production of eight haploid nuclei in a large megaspore.
1. the diploid megaspores undergoes meiosis, producing four haploid megaspores 2. one megaspore survives, enlarges and divides its nucleus by mitosis 3. while the megaspore is enlarges, its two haploid nuclui divide4. the resulting four nuclei divide yet again 5. after three rounds of mitosis, the now large megaspore had eight haploid nuclei
As the microspore divides, it produces several important features, including the ______.
two-layered wallgenerative celltube cell
As integuments develop inside the flower bud, they leave a pore, called the ________ , at one end of the ovule.
micropyle
True or false: The angiosperm female gametophyte contains seven cells with seven distinct nuclei.
False
The arrow is pointing to the ________ , which will eventually become the pollen grains.
microspores
Which of the following events does not lead to formation of a pollen grain?
The sculptured exine contains chemicals that interact with the stigma.
As the megaspore nuclei divide in the ovule of a flower bud, the two outer layers of the ovule differentiate into the ______.
integuments
The four pollen sacs found within a developing anther are lined with nutritive ________ cells
tapetal
The pollen grain may germinate if the chemicals in the exine react with the chemicals found in the _______ of a flower.
...
Pollination differs from fertilization in that it is simply the ______.
transfer of pollen to a stigma
By the time the anther has matured, the walls between the four pollen sacs break down, and how many larger sacs remain?
Two
Select all of the following that are characteristics of the outer wall of the pollen grain.
It contains chemicals that interact with the stigma.It is called the exine.
Match the following terms to their definition.
Pollination -> Transfer of pollen grains to the stigmaFertilization -> Union of the sperm and egg
In some species, self-pollination may occur, in which pollen grains ______.
germinate on the stigma of the same flower in which they were produced
If a pollen grain is from a different plant of the same species, it is very likely that the pollen grain will ______.
germinate
The outer layer of the pollen grain wall is often highly sculptured, and it is called the _______
exine
If conditions are suitable, a pollen tube will grow out of an aperture and ultimately end up at the ______.
ovule
Select the top two pollination mechanisms.
insectswind
In most plants, after pollination, the male gametophyte will not develop further unless the pollen grain is from a ______.
variety different from that of the flower receiving itdifferent plant of the same species
In the following pollen grain diagram, "A" indicates which of the following?
Aperture
What must a pollen tube pass through in order to reach the female gametophyte?
Micropyle
Starting with the stigma at the top, rank the following parts in the order that the pollen tube will grow through them.
1. Stigma2. Style 3. Ovary4. Ovule
In angiosperms, double fertilization refers to the fact that one sperm nucleus fertilizes the egg, and the other sperm nucleus unites with the ______.
two central cell nuclei
Select all of the following that are true statements concerning the endosperm in most angiosperms.
It has a triploid nucleus.It is a major development unique to angiosperms.
Examine the diagram of the pollen grain. "B" indicates ______.
sperm cells
The pollen tube discharges its contents into the female gametophyte, destroying which part in the process?
Synergid
Generally speaking, which angiosperm group has several members in which the endosperm tissue makes up an extensive part of the seed?
Monocots
In most angiosperms, the pollen tube's journey usually does not take longer than two ______.
days
Double ______ describes the event in which one sperm fuses with the egg, and the other fuses with the central cell nuclei in angiosperms
fertilization
In most angiosperms, the formation of the endosperm is unique in that the nucleus is ______,
triploid
Match each term to the part that it becomes by the end of seed development in angiosperms.
Integuments -> Seed coatOvule -> SeedOvary -> Fruit
In some monocots, the endosperm makes up a large part of the seed tissues, but in most dicots, the endosperm gets absorbed into which of the following parts by the time the seed is mature?
Cotyledon
Approximately what percentage of angiosperms produce an endosperm that does not have a triploid nucleus (e.g. the endosperm may be 5x, 9x, or even 15x)?
30%
It is important for botanists to recognize plant relationships based on ________ because otherwise, they might not recognize the accurate lineage or shared family characteristics.
evolution
When a sperm nucleus fuses with the two central nuclei of a female gametophyte, the resulting nutritive tissue is called the
endosperm
At the conclusion of seed development in angiosperms, the ovule matures into a ______ , and the ovary matures into a(n) _______
seedfruit
Select all of the following that are hypothesized features of primitive angiosperms in the Jurassic period.
Radially symmetrical flowersSimple leavesNumerous flower parts not fused together
In some lilies, one of the central cell nuclei is 3x, and the other central cell nucleus is x. During fertilization, one sperm (x) unites with the two central cell nuclei resulting in the formation of a ______ endosperm nucleus. (Type your number with an x after it.)
5x
Modern botanists prefer to use ______ to explain the evolution of natural groups of plants.
chemical componentsthe fossil record
Compared to primitive flowers, more specialized flowers often possess which of the following characteristics?
Parts that have fusedParts that have compressed into whorls
Botanists hypothesize that primitive angiosperms had which type of flower?
Flowers with numerous parts that were not fused to each other
Pistils are composed of a leaflike structure with ovules along the margin, and the edges of this blade are fused together to form a(n) ______.
carpel
Since flowers first appeared in the Jurassic period, flower parts have tended to become ______.
fewer in number
In the following image of a flower, the ovary is said to be ______.
inferior
Modern botanists prefer to use ______ to explain the evolution of natural groups of plants.
the fossil recordchemical components
The first pistil is believed to have formed from a leaflike structure with ______ found along its margins.
ovules
More advanced flowers have tended to become bilaterally symmetrical, which is to say their corolla is ______.
irregular
Examine image of a flower. The ovary featured is said to be ______.
superior
If a flower has a calyx, a corolla, stamens, and a pistil, then it is said to be ______.
complete
Examine the image. The separate carpels of primitive flowers fused together to form which of the following?
Compound pistil
Examine the photo of a squash flower. Select all of the following terms that describe the flower.
UnisexualImperfect
More advanced (modern) flowers have tended to become ______ symmetrical.
bilaterally
Which type of flower lacks one or more flower parts?
Incomplete
When male and female imperfect flowers occur on separate plants, the species is said to be ___________.
dioecious
This photo of a squash flower shows a unisexual flower, which is also referred to as _____
imperfect
Specific pollinators are said to have co-evolved with some flowering plants, and evidence for this may be seen in the ______.
highly specialized relationships between the two species
Select all of the following organisms that may be dried and stored in an herbarium.
PlantsFungiAlgae
What is the name of the device used by botanists to dry plant specimens?
Plant press
If you find both female and male imperfect flowers on the same plant, then the plant is said to be ______
monoecious
Regardless of whether it is complete or incomplete, a flower is said to be ______, if it has both stamens and pistils.
perfect
Foraging insects can directly benefit plants because they can ______.
bring about pollination when they visit plants for food
True or false: Properly prepared and stored herbarium specimens should remain in excellent condition for up to 50 years, but probably should be replaced after that time.
False
Pressed plant specimens should be mounted to which type of paper to increase longevity?
100% rag-content paper
What is a drawback of drying flowers with sand?
Sand must be washed and dried before use.
True or false: Dried plant specimens have been used extensively in research and even have been used as courtroom evidence.
True
Intact, three-dimensional flowers may be preserved in ______.
sandsilica gel
Due to the fact that so many plants are rare, it is often recommended that botanists take ______ instead of collect live plant material.
photos