Section 27.2 (Exam 2) Flashcards
Once Dominant Gymnosperms Still Thrive in Some Environments
Gymnosperms (“naked-seeded”): ovules and seeds are not protected by ________________________.
ovary or fruit tissue
Gymnosperms don’t form ___________________.
flowers or fruits
What are the 4 types of gymnosperms?
Cycads, Gingkos, Gnetophytes, Conifers
How many species of Cycads are there, and what kind of biomes do they live in?
300 species; tropical and subtropical
How many species of Ginkgos are there? Name some Ginkgos that are alive today.
One living species, Ginkgo biloba
How many species of gnetophytes are there?
90 species
How many species of conifers are there? Name some types of conifers.
700 species; cone bearers, pines, spruces and redwood
All living gymnosperms except gnetophytes have __________ for water conduction and support.
tracheids
Gymnosperms were dominant during the ____________, until about 65 million years ago.
Mesozoic
Conifers today dominate many forests, specifically at high ______________.
latitudes and altitudes
The oldest living organism on earth is a ______________ that germinated about _______ years ago.
bristlecone pine; 5000
In conifers, male and female cones contain the ______________________.
reproductive structures
What is the megastrobilus also called? Their seeds are protected by a ____________________, which are modifications of __________.
Ovulate cones; tight cluster of woody scales; branches
What is the microstrobilus also called? They are typically not woody. Their scales are modified ________, and beneath them are _________________.
Stamenate cones; leaves; pollen-bearing microsporangia
In the pine life cycle, wind carries pollen grains from __________________________.
male to female cones.
In the pine life cycle, a pollen grain enters through an opening in the __________ called the ____________.
integument; micropyle
In the pine life cycle, two sperm travel through the pollen tube, one fertilizes the egg, the other ____________.
degenerates
In the pine life cycle, the microsporangium in the ______ of the microstrobilus become a bunch of _____________ via _________.
scales; microspores; meiosis
In the pine life cycles, the microspores become _______________, which get carried by the ______ to the female gametophyte, the ___.
pollen grains; wind; egg
In the pine life cycle, the scale of the megastrobilus contains the ________, which contains the __________ and the ______________.
ovule; integument; megasporangium
What is the integument?
A hard protective layer around the embryo
In the pine life cycle, the megasporangium contains one diploid ______________. This undergoes _________, and becomes 4 haploid ___________.
Megasporocyte; meiosis; megaspores
In the pine life cycle, out of these ____ megaspores, ___ survives and the others degenerate.
four; one
In the pine life cycle, when there is one megaspore left, what happens next?
The pollen grain enters through the micropyle and travels through a pollen tube and fertilizes the egg which becomes a zygote, which is the early sporophyte (2n).
In the pine life cycle, this zygote is contained within a _________________, which is contained within the scale of the ______________. It contains the __________ seeds.
female gametophyte; megastrobilus; winged
In the pine life cycle, the female gametophyte provides __________ to the developing embryo, which eventually grows into a __________ (sporophyte).
nutrition; pine tree
Most conifer are born on the upper surfaces of the ___________. These are tightly pressed to proctect the _______.
cone scales; seed
Some pinecone scales, like _______________, can only be opened by fire. This helps ensure growth after wildfires.
lodgepole pines
Some conifers have soft, fleshy, fruit-like cone tissue surrounding seeds. One example of this are __________ berries.
juniper
Other conifers have fruitlike extensions of the seeds called arils, one example being __________ berries.
yew
Animal can eat both juniper and yew “berries”, and _________ the seeds through their feces.
disperse
