Lab 7-Gynosperms (Naked seeds) Flashcards
Gymnosperms = ___ seeds
naked
In Gymnosperms, the ___ and seeds are borne ___ on the surface of the ___
ovules, exposed, sporophylls
Four evolutionary processes occurred as non-seed plants evolved:
- reduction in gametophyte size and complexity
- retention of the gametophytes on the sporophytes
-to reduce exposure to the environment and to get protection, nutrients and moisture from the sporophyte - development of the seed
-to protect and nourish the embryo (seeds survive longer than spores)
4.reduction of the need for water for fertilization
-wind dependent
All angiosperms and gymnosperms are ___
heterosporous
Mega and microsporangia are location on ___ strobili
seperate
The megasporangiate strobilus is often called the ___ cone or ___ cone
female, seed
The microsporangiate strobilus is often called the ___ cone or ___ cone
male, pollen
For the first time, we find extra protective tissue called the ___ around the ___, now called the ___
integument, megasporangium, nucellus
The ___ surrounds a ___ megaspore ___ cell, which will develop into ___ megaspore (n); of the ___ megaspores produced through ___, only ___ develops and the other ___ degenerate
nucellus, single, mother, four, meiosis, one, three
The nucellus together with the ___ is considered an ___; generally located on the ___ (___)
integument, ovule
strobilus, cone
Microsporangium=
pollen sac
In gymnosperms, the process of ___ transfer from the microsporangium to the ___ is called ___
pollen, ovule, pollination
The pollen must travel to the ___ on the ___ cones and pass through the ___ via a channel called the ___
ovules, female, integument, microphyll
In pollen sacs, ___ germinate into young microgametophytes = ___ that develop thick protective walls. Only then are they released from the ___
microspores, pollen (n), microsporangium
The megagametophyte is retained within the ___, which was mostly ___ as food for the growing ___
nucellus, digested, megagametophyte
The appearance of the ___ was and adaptation of major importance to the evolution of plants
seed
The seed is essentially an ___ with its own ___ source and protection from ___
embroyo, food, dessication
The seed has adaptations for dispersal by ___, ___ or by ___
wind, water, animals
Once the ___ in the archegonium of a ___ is ___, the ___ (the new sporophyte, 2n) begins to grow and is retained in the ___ digesting it for ___.
egg, megagametophyte, fertilized, embryo, megagametophtye, nourishment
The surrounding ___also undergoes changes following fertilization to become the ___ ___
integument, seed coat
What four things become the seed?
integument, nucesllus, megagametophyte, embroyo
The seed leaves the protection of the mature ___ and is dispersed so new sites where the new ___ within the seed with continue to grow.
sporophyte
Similarities in the reproduction of cycads, ginkgos, and conifers
produce two sperm per pollen grain
Differences in the reproduction of cycads, ginkgos, and conifers
1.cycads and ginkgo’s have flagellated sperm; conifers don’t (have two male nuclei)
-water still required for sperm to swim to egg
2. main function of pollen tube of cycads and gingko’s is for anchorage and nutrient absorption; main function in conifers is to grow down to penetrate the neck cells of the female gametophyte’s archegonium and deliver the male gametes directly to the egg
Cycads (cycadophyta) represent the most ancestral of the extant __ plants and the most ancestral type of ___ reproduction
seed
Cycads (cycadophyta)are ___
dioecious
Cycad strobili are highly modified short stems with ___ . They may be modified __ vs lycophytes, that had sporophyll modified from a microphyll
sporophylls, megaphylls,
What are in the four celled polen grain in the microspore of Cycads (cycadophyta):
- prothallual cell
- tube cell
- stalk cell
- body cell
The body cell in Cycads (cycadophyta) divides producing __ sperm per pollen grain
two
The pollen in Cycads (cycadophyta) will be released and eventually land on a ___ ___ (sticky liquid) located at the microphyll of an ___
pollen drop, ovule
What forms from the pollen drop resorbing and pulling down through the micropyle into the pollen chamber where it settles onto the surface of the nucellus in Cycads (cycadophyta)
pollen tube
What is the function of the pollen tube in Cycads (cycadophyta)?
anchorage and nutrient absorption
Is the sperm flagellated and motile? Is fluid needed for fertilization in Cycads (cycadophyta)
yes, yes
What is the nutrient source for the growing megagametophyte in Cycads (cycadophyta)
embroyo
Define the term ovule
=the nucellus (megasporangium) together with the integument (extra protective tissue)
What structure does the integument develop into in Cycads (cycadophyta)
seed coat
What is the nutrient source for the embroyo in Cycads (cycadophyta)
megagametophyte
Cycads (cycadophyta) are the first to show true secondary or primary growth?
secondary
Scale leaves are highly modified ___ that cover the shoot __
leaves, apex
Scale leaves are often retained as ___ scales covering the upper portion of the ___ in Cycads (cycadophyta)
fibrous, stem
Are scale and foliage leaves microphylls or megaphylls in Cycads (cycadophyta)
megaphylls
Are the foliage leaves simple or compound in Cycads (cycadophyta)
pinnately compound
Do scale leaves photosynthesize in Cycads (cycadophyta)
no; protect and support
What is the function of scale leaves in Cycads (cycadophyta)
protect auxiliary bud (shoot apex)
What type of leaf venation in the foliage leaves on Cycads (cycadophyta)
dichotomous venation (single main vein, small veins branch off)
What is the leaf arrangement in Cycads (cycadophyta)
spiral or whorled
There is only ___ order, family, genus, and species left in ginkgo (ginkgophyta)
one
The mature male gametophyte has two ___ cells in ginkgo (ginkgophyta) (compared to ___ in cycads), a __ cell and a ___cell
prothallial, body, tube
Like cycads, gingko produces ___ mutli-flaggelate sperm that are released into the fluid filled archegonial chamber. They swim trough the ___ cells of the ___ to the ___ in ginkgo (ginkgophyta)
two, neck, archegonium, egg
Ovules are formed at the tip of a short ___ and not within a ___ in ginkgo (ginkgophyta)
stem, cone
What structure will the functional megaspore develop into in ginkgo (ginkgophyta)
ovule (where egg cells are housed)
Where would leaves be located on the branch on ginkgo (ginkgophyta)
alternate fashion along branches (leaf on each node of branch)
Are the leaves microphylls or megaphylls in ginkgo (ginkgophyta)
megaphylls
Are the leaves simple or compound in ginkgo (ginkgophyta)
simple
What type of leaf venation in ginkgo (ginkgophyta)
dichotomous
In conifers (coniferophyta), fluid is no longer needed to mediate gamete delivery, therefore sperm are not ___. They are instead ___ pollinated
flagellated, wind
Male gametes are delivered directly to the ___ cells as the ___ tube penetrates directly into the ___ through the ___ cells in conifers (coniferophyta) rather than dropping the male gametes into an archegonial chamber as in cycads
egg, pollen, archegonium, neck
The ___ cone contains microsporophylls each with ___ microsporangia in conifers (coniferophyta)
pollen, two
Which cells produce the two male gametes? Does this occur by mitosis or meiosis conifers (coniferophyta)
generative cell (within pollen tube); mitosis
Are the gametes flagellated in conifers (coniferophyta)
no
What is the function of the pollen tube in conifers (coniferophyta)
grow down to penetrate the neck cells of the female gametophyte’s archegonium and deliver the male gametes directly to the egg
Within the bud scales of the bud is a developing ___ ___ (female reproductive structure) in conifers (coniferophyta)
seed cone
3/5 differences in life cycle of conifers (coniferophyta)
- heterospory
- separate male and female gametophytes
- reduced gametophytes attached to and dependent on the sporophyte
- development of a pollination step BEFORE the fertilization process
- pollen tube that eliminates the need for free water for fertilization
The terminal and lateral buds of conifers can be two types: ___ (pines, douglas firs) and ___ (hemlock, cedar) in conifers (coniferophyta)
determinate, indeterminate
Most of the growth for the ___ season is already initiated in ___ buds in conifers (coniferophyta)
next, determinate
Within the determinate bud types are two subtypes: ___ ___ and ___ ___
simple determinate, compound determinate
Very little of the growth for the ___ season is initiated prior to the start of that season in ___ ___ in conifers (coniferophyta)
indeterimanate buds
Bud scales in pines are called ___ in conifers (coniferophyta). They are not all on the ___ of the apex but inserted ___ each fascicle primordium
cataphylls, outside, under
