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,
