30 Flashcards
seed
consists of an embryo and nutrients surrounded by a protective coat
what are common to all seed plants?
- Reduced gametophytes
- Heterospory
- Ovules
- Pollen
Gymnosperm
refers to the exposed nature of the seeds
“naked seed” not enclosed by ovaries and are exposed to sporophylls that usually form cones
Seeds produced on surface of _____ or similar structures, instead of enclosed within a fruit as in flowering plants.
sporophylls
Phylum Coniferophyta
This phylum is by far the largest of the gymnosperm phyla (~600 species)
• Most conifers are evergreens and can carry out photosynthesis year round and dominate northern forests
Three key features of the gymnosperm life cycle are:
- Dominance of the sporophyte generation
- Development of seeds from fertilized ovules
- The transfer of sperm to ovules by pollen
The gymnosperms have “naked” seeds not enclosed by ovaries and consist of four phyla:
– Cycadophyta (cycads)
– Gingkophyta (one living species: Ginkgo biloba)
– Gnetophyta (three genera: Gnetum, Ephedra, Welwitschia)
– Coniferophyta (conifers, such as pine, fir, and redwood)
Phylum Cycadophyta
• Individuals have large cones and palmlike leaves (but are not palms!)
– Slow-growing plants of tropics and subtropics
– Tall unbranched trunks
– Crown of large pinnately
divided leaves
• Thesethrivedduringthe Mesozoic, but relatively few species exist today
Phylum Ginkophyta
Only one living species:Ginkgo biloba (maidenhair trees)
• Only exists in cultivation
– Notched, broad, fan-shaped leaves
• Leaves on short, slow-growing spurs.
– No midrib or prominent veins – Hair-like veins branch
dichotomously. – Dioecious!
what is pollination?
is the act of transferring pollen grains from the male anther of a flower to the female stigma
what is a fruit
Matured ovary and its accessory parts
– Contains seeds
– All fruits develop from flower ovaries and accordingly are found exclusively in flowering plants.
double fertilization
occurs when the pollen tube discharges two sperm
into the female gametophyte within an ovule
____ and ___ are key adaptations for life on land
seeds and pollen grains
a microspore develops into a
pollen grain
in gymnosperms, the seeds are produced where? as opposed to flowering plants
produced on sporophylls as opposed to inside of a fruit in flowering plants
the pine tree is the ____ and produces ____
sporophyte and produces sporangia in male and female cones
Small cones produce _____ called ____ each of which contains a ____ gametophyte
microspores; pollen grains; male
familiar larger cones contain ,which produce _____ that develop into _____ gametophytes
ovules; megaspores; female
It takes nearly ___ years from cone production to mature seed
three
what are the four phyla of the gymnosperms?
– Cycadophyta (cycads)
– Gingkophyta (one living species: Ginkgo biloba)
– Gnetophyta (three genera: Gnetum, Ephedra, Welwitschia)
– Coniferophyta (conifers, such as pine, fir, and redwood)
Dioecious
Male and female structures on separate trees.
phylum gingkophyta
angiosperms
seed plants with reproductive structures called flowers and fruits; They are the most widespread and diverse of all plants
All angiosperms are classified in a single phylum, _____ (aka Anthophyta)
Magnoliophyta
exocarp
skin
endocarp
inner boundary around seed
mesocarp
Tissue between exocarp and endocarp
Three regions collectively called
pericarp
True fruits contain only______ ; accessory fruits are those that contain any _______
ovarian tissue; nonovarian tissue
fleshy
mesocarp is at least partly fleshy at maturity.
Simple fleshy fruits develop from a flower with a single pistil
Are eaten during the natural seed distribution process
dry
mesocarp is dry at maturity
Is typically not eaten by the natural seed- distributing animals
what are fruit adaptations that enhance seed dispersal?
wind, animal transportation, animal ingestion
flower of the sporophyte is composed of ______
both male and female structures
____ are contained within pollen grains produced by the
microsporangia of anthers
male gametophytes
The female gametophyte, or _____ , develops within an ovule contained within an ovary at the base of a stigma
embryo sac
The ovule is entered by a pore called the
micropyle
_____ occurs when the pollen tube discharges two sperm
into the female gametophyte within an ovule
double fertilization
One sperm fertilizes the egg, while the other combines with two nuclei in the central cell of the female gametophyte and initiates development of food- storing _____
endosperm
The _____ nourishes the developing embryo
endosperm
More than _____ of world’s plants face extinction
1/5
flower
a unique angiosperm structure specialized for sexual reproduction
ovary matures into a ____
fruit
monocot
species with one cotyledon (an embryonic leaf in seed-bearing plants, one or more of which are the first leaves to appear from a germinating seed.)
dicot
two cotyledon
eudicots
true dicots
magnoliids
Magnoliids are a group of flowering plants. ; fourth lineage
human welfare depends on plants. provide examples
– Gymnosperms supply most of our lumber and paper.
– Angiosperms
• Provide nearly all our food
• Supply fiber, medications, perfumes, and decoration
– Agriculture is a unique kind of evolutionary relationship between plants and animals.
In which one of the following major plant groups do most of the species NOT produce flagellated sperm?
seed plants
Which one of the following is true of seed plants, but not of seedless plants?
The gametophyte is reduced and dependent on the sporophyte.
The eggs of seed plants are fertilized within ovules, and the ovules then develop into _____.
seeds
A pea pod is formed from ____. A pea inside the pod is formed from ____.
an ovary … an ovule
The diploid generation of the plant life cycle always _____.
produces spores
Which evolutionary advance gave the gymnosperms an adaptive advantage at the time they were evolving?
seed
Seeds have advantages over spores. For example, __________.
seeds contain the young plants, an abundant food supply, and a protective covering
All seed plants ____________.
are heterosporous
Both gymnosperms and angiosperms have _____.
pollen, seeds, and ovules.
Gymnosperms __________.
produce seeds that are totally exposed
An explorer found a plant that had roots, stems, and leaves. It had no flowers but produced seeds. This plant sounds like a(n) _____.
gymnosperm
Which of the following best describes how fertilization occurs in a conifer?
A pollen grain carried by wind carries a sperm that fertilizes the egg.
The male gametophyte in pine is commonly known as _____.
pollen
Conifers usually ____________.
bear both male and female cones on the same tree
Pollen is __________ and contains __________.
haploid … sperm nuclei
All gametophytes are _____.
haploid
Most species of plants are _____.
angiosperms
The defining reproductive adaptation of angiosperms is the __________.
flower
The portion of the flower that receives the pollen is the _____.
stigma
In the process of pollination, pollen grains are transferred from the _____ to the _____.
anther … stigma
Male floral parts include __________.
stamens: anthers and filaments
The “male” structures of angiosperms are called __________, and they produce __________.
anthers … pollen
The “female” structures of angiosperms are called __________, and they produce __________.
carpels … ovules
A fruit is a mature _____.
ovary
After fertilization, the _____ develops into a seed and the _____ develops into a fruit.
ovule … ovary
Aggregate fruit is formed from __________; simple fruit is formed from _______; and multiple fruit is formed from ________.
a single flower with several separate ovaries … a single ovary … the fusion of ovaries of separate flowers
Which one of the following best describes the function of fruits?
to protect and disperse the seeds
What do the “mono-“ and “-di-“ refer to in “monocots” and “dicots”?
the number of “seed leaves”
In a flowering plant, meiosis occurs within the _____, producing a spore that develops into a female gametophyte
ovule
Select the INCORRECT association.
sepals … containment of sporangia
Meiosis will produce microspores in the _____.
anther
All of the following are true about angiosperm spores EXCEPT _____
the spores are part of the asexual reproductive cycle
Which one of the following is diploid?
megasporocyte
The pollen tube releases two sperm cells into the embryo sac. The result of this is the _____.
union of one sperm nucleus with the egg nucleus while the other sperm nucleus unites with the nuclei of the center cell, forming a triploid nucleus
The triploid nucleus of the embryo sac develops into the _____.
endosperm
In angiosperms, each pollen grain produces two sperm. What do these sperm do?
One fertilizes an egg and the other fertilizes a cell that develops into stored food.
What is endosperm?
stored food in a seed
Unlike gymnosperms, angiosperms have _____.
endosperm
Double fertilization __________.
the second and third choices
In gymnosperms, the seed coat develops from the integuments. In angiosperms, the seed coat develops from the ____.
integuments
A plant is said to be cross-pollinated if __________.
pollen grains are transferred to a flower on a different plant
Some plants have evolved to attract specific animals. The animal receives a meal and the plant is assured that its pollen will not be wasted on plants of different species. Through time, the plant gets better at attracting that animal and the animal gets more specialized for feeding on that plant. This type of long-term interplay between populations is referred to as _____.
coevolution
At current rates of deforestation, tropical rain forests will be eliminated in ______ years.
25
You find a wildflower that has large, brilliantly colored petals, but it has no odor. What can you deduce about its pollinators?
Its pollinators locate flowers by visual cues rather than by smell.
Like gymnosperms, many grasses and angiosperm trees are wind-pollinated. To conserve energy, these angiosperms do not produce complete flowers (complete flowers have all four of the basic parts). Which part would wind-pollinated angiosperms be most likely NOT to have?
petals
Most of the seeds used for human consumption come from __________.
angiosperm
The evolutionary advance that made possible the colonization of dry environments by seed plants is most likely the result of the evolution of _____.
pollen
Gymnosperms were most abundant during the _____.
mesozoic
The major difference between angiosperms and gymnosperms comes from the __________.
presence or absence of a protective covering over the ovule
Unlike most angiosperms, grasses are pollinated by wind. As a consequence, some unnecessary parts of grass flowers have almost disappeared. Which of the following parts would you expect to be most reduced in a grass flower?
petals
where in an angiosperm would you find a megasporangium?
within an ovule contained within an ovary of a flower
key features of seed plants facilitating life on land include three of the following traits. select the exception
homospory
with respect to angiosperms, which of the following is incorrectly paired with the chromosome count
megaspore -2n
which of the following is not a characteristic that distinguishes gymnosperms and angiosperms from other plants?
alteration of generations
gymnosperms and angiosperms have the following in common except
ovaries
megaspores give rise to
female gametophytes
microsporangia on microsporophylls produce
microspores that give rise to male gametophytes
each megasporangium has ___ megaspore where as microsporangium has ___ microspores
one; many
the ____ of an ovule develops into the proactive coat of a seed
integument
