ch. 30 Flashcards
In addition to seeds, what is common to all seed plants (4)
1) Reduced Gametophytes
2) Heterospory
3) Ovules
4) Pollen
Reduced Gametophytes characteristics (2)
1) Gametophytes of seed plants are microscopic
2) Develop within walls of spores retained within the tissue of parent sporophyte to protect developing gametophyte
Giant Gametophyte
Gametophyte: Dominant
Sporophyte: Reduced, depends of gametophyte for nutrition
Mosses and nonvascular plants
Small Gametophyte
Gametophyte: Reduced, independent
Sporophyte: Dominant
seedless vascular plants
Tiny Gametophyte
Gametophyte: Reduced, microscopic, dependent on sporophyte, in ovulate and pollen
Sporophyte: Dominant
Seed plants (gymnosperms and angiosperms)
Homosporous
Plants that produce one kind of spore, usually produces bisexual gametophyte
Ex. Ferns
Heterosporous
Produce two types of spores, which develop to either male or female gametophytes
Ex. Seed plants
Microsporocytes (2n) give rise to
microspores (n) (meiosis)
Gametophyte (n) produces
Gametes (mitosis)
Megasporangia
1) produce megaspores that give rise to female gametophytes
2) develop on megasporophylls
microsporangia
1) produce microspores that give rise to male gametophytes
2) develop on microsporophylls
Chain of mega
Megasporophylls contain megasporangia containing megasporocytes which make megaspores
chain of micro
microsporophylls contain microsporangia containing microsporocytes which make microspores
Ovules consists of? (3)
Consist of:
1) Megasporangium (2n)
2) megaspore (n)
3) Integument (2n)
- 1 integument for gymnosperm
- 2 integument for angiosperm
What is a pollen grain
a developed microspore that contains a male gametophyte
What is pollination?
transfer of pollen to ovules
Germinated pollen grain produces
Pollen tube that discharges sperm into female gametophyte in ovule
Where are Gymnosperms seeds located?
Exposed on sporophylls that form cones
Where are Angiosperm seeds located?
Found in fruits, mature ovaries
Life cycle of pine (male)
1) Pollen cones contain microsporophyll which contain microsporangia
2) Within the microsporangia there are cells called microsporocytes that go through meiosis to make microspores
3) Microspores turn into pollen grain(n) which have male gametophyte
Life cycle of pine (female)
1) Ovulate cones contain Megasporophylls(2n) that bear megasporangia(2n) and stem tissue
2) The megasporocytes in the megasporangia go through meiosis to produce haploid megaspores
3) Megaspores develop into female gametophytes which are retained in the megasporangia
4 Gymnosperm phyla
1) Cycadophyta
2) Ginkgophyta
3) Gnetophyta
4) Coniferophyta
Cycadophyta
1) Large cones and palm like leaves
2) Has flagellated sperm
Ginkgophyta (3)
1) One living species, Ginkgo biloba
2) Has flagellated sperm
3) has high tolerance for air pollution
Gnetophyta (2)
1) 3 genera: Gnetum, Ephedra, Welwitschia
2) Vary in appearance and location
Ephedra
anxiety
Sinica
psychosis
Coniferophyta (3)
1) Largest of the gymnosperm
2) Mostly woody cones
3) Mainly evergreens
Angiosperm (domain, kingdom, phylum)
Domain: Eukarya
Kingdom: Plantae
Single Phylum: Anthophyta
Flower and fruits
What is the purpose of Flowers?
Angiosperm meant for sexual reproduction
4 Floral organs
Sepals
Petals
Stamens
Carpel
Sepals characteristics (3)
Enclose the flower
protect unopened floral buds
resemble leaves
explain the coloration of Petals
Bright color to attract pollinators or no color if wind pollinated
Stamens characteristics(2)
1) Male reproductive organs
2) Contain filament, with a sac called anther
Carpels characteristics(2)
1) Female Reproductive organs
2) Has an ovary at the base of a style leading up to stigma (where pollen is received)
Fertilized ovules develop into seeds
What do Stamens contain?
Contain filament, with a sac called anther
What are microspores
produced in anthers, develop into pollen grains containing male gametophytes
What is an Anther
sac on the stamen, produces and holds microspores (pollen)
What are Pistil
Single carpel or two or more fused carpels
Radial Symmetry
Any imaginary line through the central axis divides the flower into two equal parts
Bilateral Symmetry
Flower can only be divided into two equal parts by a single imaginary line
When do Fruits form? What is its function?
Formed when ovary wall thickens and matures
Protects seeds and aid in dispersal
Male gametophytes located where on Angiosperms
In pollen grains produced by the microsporangia of anther
Female gametophyte located where on angiosperms
Within an ovule within an ovary at the base of a stigma
Micropyle
Ovule is entered through a pore called the micropyle
Double Fertilization
when pollen tube discharges two sperm into the female gametophyte within an ovule
What starts the development of endosperm
One Sperm must fertilize the egg, the other combines with two polar nuclei in the central cell of female gametophyte
Cotyledons
One/two seed leaves
