Chapter 30: Modern Gymnosperms and Angiosperms Flashcards
A ____ consists of __ ____ and ______ surrounded by a protective coat
1) Seeds and pollen grains are key adaptations for life on land
seed
an embryo
In addition to seeds, the following are common to all seed plants
1) ________ gametophytes
2) ________ (♀ megaspore and ♂ microspore)
3) _____ (♀, within is the Egg)
4) _____(♂, within is the Sperm)
Reduced gametophytes
Heterospory
Ovules
Pollen
__________ produce megaspores
a) This gives rise to female gametophytes
Megasporangia
_________ produce microspores
a) This gives rise to male gametophytes
Microsporangia
Within the ovule the ________ is found
megaspore
Gymnosperm megaspores have #_ _______
one integument
Angiosperm megaspores usually have #_ _______
two integuments
Microspores develop into ______ ____, which contain the male gametophytes
pollen grains
If a pollen grain germinates, it gives rise to a _____ ____ that discharges two sperm nuclei into the female gametophyte within the ovule
pollen tube
The gymnosperms have:
1) “Naked” seeds not enclosed by ovaries and lacking fruit
2) Consist of four phyla:
a) _________ (cycads)
b) _________ (one living species: Ginkgo biloba)
c) _________ (three genera: Gnetum, Ephedra, Welwitschia)
d) ________ (conifers, such as pine, fir, and redwood)
Cycadophyta
Gingkophyta
Gnetophyta
Coniferophyta
Fossil evidence reveals that some plants had begun to acquire some adaptations that characterize seed plants
a) Early plants were called ___________,
progymnosperms,
Living seed plants can be divided into two clades:
_______
_______
a) Gymnosperms
b) Angiosperms
Today, cone-bearing gymnosperms called _____ dominate in the northern latitudes
b. Gymnosperms are better adapted to colder conditions than _________
conifers
Angiosperms
Individuals have large cones and palmlike leaves
b. These thrived during the Mesozoic, but relatively few species exist today
Phylum Cycadophyta
a. This phylum consists of a single living species, Ginkgo biloba
b. It has a high tolerance to air pollution and is a popular ornamental tree
Phylum Ginkgophyta
a. This phylum comprises three genera only
b. Species vary in appearance
Phylum Gnetophyta
a. This phylum is by far the largest of the gymnosperm phyla
b. Most conifers are evergreens and can carry out photosynthesis year round
Phylum Coniferophyta
Three key features of the gymnosperm life cycle are:
a. Dominance of the ________ ________
b. Development of seeds from ______ _____
c. The transfer of sperm to ovules by _____
sporophyte generation
fertilized ovules
pollen
It takes nearly three years from cone production to mature seed
1) Year 1: ovules (♀) and pollen (♂) develop within each cone, and pollen fertilizes the female ovule (cone stays on the tree)
2) Year 2: in the summer the cone, with fully developed embryos, falls to ground, but the cone stays tightly closed
3) Year 3: during the summer the cone opens and releases fully matured seeds that can then sprout and produce a seedling
It takes nearly three years from cone production to mature seed
1) Year 1: ovules (♀) and pollen (♂) develop within each cone, and pollen fertilizes the female ovule (cone stays on the tree)
2) Year 2: in the summer the cone, with fully developed embryos, falls to ground, but the cone stays tightly closed
3) Year 3: during the summer the cone opens and releases fully matured seeds that can then sprout and produce a seedling
Embryogenesis
1) A spherical embryo grows to form a heart-shaped embryo, that then forms a torpedo-shaped embryo
a) The lobes of the heart are the _____ (becomes the shoot) and the ________ (becomes the root)
epicotyl
hypocotyl
The embryo has three cell layers:
1) ________: outer»_space; epidermis
(2) ________: middle»_space; ground tissue (cortex
(3) ________: inner»_space; vasculature
ectodermis
mesodermis
endodermis
The reproductive adaptations of angiosperms include _____&_____
flowers and fruits
________: a specialized structure for sexual reproduction; often contains both the microsporangium (pollen) and megasporangium (ovule)
Flower
_______ : develops from the fertilized central cell within the ovule
Fruit
Angiosperms are seed plants with reproductive structures called flowers and fruits that are NOT
found in Gymnosperms
. All angiosperms are classified in a single phylum, _______
a. The name comes from the Greek anthos, flower
Anthophyta
The flower is an angiosperm structure specialized for ______ reproduction
b. Many species are pollinated by insects or animals
1) While some species are wind-pollinated
sexual
. A flower is a specialized shoot with up to four types of modified leaves:
1) ______ , which enclose the flower
2) ______ , which are brightly colored and attract pollinators
3) ______ , which produce pollen
4) ______ (or Pistils), which produce ovules
Sepals
Petals
Stamens
Carpels
______ the terminal portion of the stamen; where the pollen
is produced
Anthers
hold the anthers a distance from the female stigma
Filaments
____ a long extension, through which a pollen tube grows
(1) A pollen tube can also be called a germ tube
Style
_____ on top, sticky, where pollen is received
Stigma
Fruit tissue is formed from a #_____ fertilization between the ovule central cell (contains 2 haploid nuclei, 2n) and a pollen nucleus (n)
second
_______ ______ occurs when the pollen tube discharges two pollen nuclei into the female gametophyte within an ovule.
1) One pollen nucleus fertilizes the egg
2) The other pollen nucleus combines with two nuclei in the central
Double fertilization
_______ develops into the ______ ____ (develops into the rest of the Root)
Hypocotyl
Radicle Meristem
______ develops into the ______ _____ (develops into the rest of the Shoot)
Epicotyl
Apical Meristem
One cotyledon: characteristic of _____________ plants (Monocots) (Example: corn)
Monocotylendonous
Two cotyledon: characteristic of _____________plants (Eudicots) (Example: beans)
Dicotylendonous
Angiosperms originated at least ___# ______ years ago
140million
There are four clades: \_\_\_\_ \_\_\_\_\_\_\_\_ (oldest), \_\_\_\_\_\_\_\_ (less developed, share some traits with basal angiosperms), \_\_\_\_\_\_\_ (one cotyledon) \_\_\_\_\_\_ (“true” dicots, two cotyledons)
Basal Angiosperms
Magnoliids
Monocots
Eudicots
Products from Seed Plants
a. Most of our food comes from _______
b. Six crops yield 80% of the calories consumed by humans
1) Wheat, rice, maize, potatoes, cassava, and sweet potatoes
angiosperms
