Ch 28: Seed Plants
________ are woody plants that produce seeds in cones.
*Conifers*
______ have seed cones and compound leaves.
*Cycads*
____________ is the only living species in its phylum.
*Ginkgo biloba*
___________ include three unusual genera.
*Gnetophytes*
___________________ are the two largest classes of flowering plants.
*Monocots and eudicots*
_____ represent a typical conifer lifestyle.
*Pines*
True or false Seeds and fruits develop after fertilization in flowers.
*True*
True or False? Seeds are reproductively superior to spores.
*True* 1. A seed is *further along in development before it is released* to survive on its own 2. A seed contains an *abundant food supply* 3. A seed is *protected by a multicellular seed coat* that is very thick and hard in some plants
Fruit
*a mature ovary* • The fruit takes many forms. - dry or fleshy *Function: seed dispersal* - wind, attachment to animals, food for animals
This flowering plant may be the nearest living relative to the ancestor of all flowering plants. a) Amborella b) Archareopteris c) Gnetum d) water lily e) magnolia
*a) Amborella*
Incomplete flower
lacks one or more of these four parts: sepals, petals, stamens, and carpels
Cotyledon
the seed leaf of a plant embryo, which may contain food stored for germination
Ovule
the structure in the plant ovary that develops into the seed following fertilization; also called megasporangium
Receptacle
the tip of the flower stalk that bears the flower parts
Angiosperm
the traditional name for flowering plants; a very large (300,000 species), diverse phylum of plants that form flowers for sexual reproduction and produce seeds enclosed in fruits; include monocots and eudicots • flower: sexual organ of flowering plants - flower structures work together to ensure reproduction - flowers help bring mates together
Flowers are reproductive shoots composed of four parts. Name them.
sepals, petals, stamens, and carpels
Monoecious
separate *male and female reproductive parts* in different locations *on the same plant*
Endosperm
the 3n nutritive tissue that is formed at some point in the development of all angiosperms
Peduncle
the end of a flower stalk
Petals
the whorl just above the sepals; broad, flat, and thin but vary in shape and are frequently brightly colored; attract animal pollinators to the flower
Filament
thin stalk apart of the stamen
After fertilization, the ______ develop(s) into a fruit and the _____ develop(s) into a seed. a) ovary; ovule b) polar nuclei; ovule c) ovary; endosperm d) ovule; ovary e) ovule; polar nuclei
*a) ovary; ovule*
The transfer of pollen grains from the male to the female reproductive structure is known as a) pollination b) fertilization c) embryo sac development d) seed development e) fruit development
*a) pollination*
Conifers, cycads, ginkgo, and gnetophytes are collectively called a) club mosses b) gymnosperms c) angiosperms d) eudicots e) seedless vascular plants
*b) gymnosperms*
The female gametophyte in flowering plants is also called the a) polar nuclei b) anther c) embryo sac d) endosperm e) sporophyll
*c) embryo sac*
There are at least _____ species of flowering plants worldwide a) 300 b) 3000 c) 30,000 d) 300,000 e) 3,000,000
*d) 300,000*
A flower that lacks stamens is both __________ and _________. a) complete; imperfect b) incomplete; perfect c) complete; perfect d) incomplete; imperfect
*d) incomplete; imperfect*
The immature male gametophytes of pine are called a) ovules b) stamens c) seed cones d) pollen grains e) polar nuclei
*d) pollen grains*
The life cycle of flowering plants includes ___________________.
*double fertilization*
Seed plants lack which of the following structures? a) ovules surrounded by integuments b) microspores and megaspores c) vascular tissues d) a large, nutritionally independent sporophyte e) a large, nutritionally independent gametophyte
*e) a large, nutritionally independent gametophyte*
Motile sperm cells are found as vestiges in these two gymnosperm groups: a) monocots, eudicots b) gnetophytes, conifers c) gnetophytes, flowering plants d) cycads, conifers e) cycads, ginkgo
*e) cycads, ginkgo*
What does each seed consist of?
*embryonic sporophyte, nutritive tissue (food source), and a protective coat* -seeds develop from the fertilized egg cell, the female gametophyte, and its associated tissues
Pistil
*female part of the flower*; may consist of a single carpel or group of fused carpels; consists of the stigma, stile, and ovary
Sexual reproduction takes place in _______.
*flowers*
Angiosperm (flowering plant)
*largest and most diverse seed plants* •Flower: sexual organ of flowering plants - flower structures work together to ensure reproduction - flowers help bring mates together ex. rice, wheat, corn, potatoes, tomatoes, beans, apples, and citrus fruits - oak, cherry, and walnut provide lumber • Flowering plants give us fibers, such as cotton and linen, and medicines, such as digitalis and codeine
Seed plants produce _____, each of which is a megasporangium surrounded by integuments, layers of sporophyte tissue that enclose the megasporangium.
*ovule* - after fertilization takes place, the ovule develops into a seed and the megasporangium develop into the seed coat
Some seedless vascular plants are heterosporous. However, all _________ are heterosporous and produce two types of spores: microspores and megaspores.
*seed plants*
Although gymnosperms and angiosperms also produce spores, their primary means of reproduction and dispersal is by _____.
*seeds*
Gymnosperms are classified into 4 phyla which are...
1. *Phylum Coniferophyta* - conifers - largest phylum of gymnosperms 2. *Phylum Ginkgophyta* - evolutionary remnant of a group more significant in the past 3. *Phylum Cycadophyta* - evolutionary remnant of a group more significant in the past 4. *Phylum Gnetophyta* - collection of some unusual plants that share certain traits not found in other gymnosperms - were thought to be more closely related to angiosperms but current evidence suggests they are probably most closely related to conifers
The basal angiosperms comprise three clades. Name them.
Amborella, water lilies, and star anise; thought to be ancestral to all other flowering plants
What is the difference between gymnosperms and angiosperms?
Gymnosperms have a naked seed while angiosperms have a seed enclosed within a fruit.
Explain the relationship between the gametophyte and sporophyte in seed plants.
The female gametophyte is attached to and nutritionally dependent on the sporophyte generation; *gametophyte is small and inconspicuous*
Imperfect flower
a flower that has stamens or carpels, but not both
Perfect flower
a flower with both stamens and carpels
Style
a necklace structure through which the pollen tube grows
Seed
a plant reproductive body consisting of a young, multicellular plant and nutritive tissue (food reserves), enclosed by a seed coat
Alternation of generations
a type of life cycle characteristic of plants and a few algae and fungi in which they spend part of their life in a multicellular n gametophyte stage an part in a multicellular 2n sporophyte stage
Choose one: Seed plants are (homosporous/heterosporous).
all seed plants are *heterosporous* and produce two types of spores: microspores and megaspores - requirement of seed production
Ovary
an enlarged structure that contains one or more ovules
Gymnosperm
any of a group of seed plants in which the seeds aren't enclosed in an ovary; gymnosperms frequently bear their seeds in cones; include four phyla: cycads, conifers, ginkgos, & gnetophytes - "naked seed" - no flowers or fruit - cone - wind pollination
Simple pistil
contains a single carpel
Complete flower
flower that has all four parts: sepals, petals, stamens, and carpels
What are the two groups of seed plants?
gymnosperms and angiosperms
Compound pistil
has two united carpels
Dioecious
having male and female reproductive structures on separate plants
Carpels
in the center of most flowers; the "female" reproductive organs; bear ovules; carpels can be separate or fused into a single structure; *The female part is the pistil and it contains: a stigma, style, and ovary
Magnoliids
include species in the magnolia, laurel, and black pepper families; traditionally classified as with the eudicots as "dicots" but molecular evidence indicates they're neither eudicots nor monocots - native to tropical or warm temperate regions - include several economically important plants, such as avocado, black pepper, nutmeg, and bay laurel
Stamens
located inside the petals; each stamen is composed of a thin stalk (filament) and a saclike anther
The core angiosperms comprise _____________________________.
magnoliids, monocots, and eudicots
Sepals
make up the lowermost and outermost whorl on a floral shoot; leaflike in appearance and often green; *cover and protect the other flower parts when the flower is a bud*
Eudicots
oaks, roses, mustards, cacti, blueberries, and sunflowers - either herbaceous (tomato plant) or woody (hickory tree) - leaves vary but broader than monocot leaves, with *finely branched veins* - flower parts usually occur in multiples of fours and fives - two cotyledons present in eudicot seeds and endosperms usually absent in the mature seed (absorbed by two cotyledons during seed development)
Monocots
palms, grasses, orchids, irises, onions, and lilies - mostly herbaceous plants with long, narrow leaves that have parallel veins - parts of the flower usually occur in threes - single cotyledon, or embryonic seed leaf; endosperm present in mature seed
Anther
where meiosis occurs to form microspores that develop into pollen grains
Stigma
where the pollen grain lands
Flower modifications
• Complete flowers have sepals, petals, stamens, and a pistil. • Perfect flowers have stamens and a pistil
List similarities and differences between gymnosperms and angiosperms
• Similarities - xylem - phloem • Differences - angiosperms have an ovary wall that surrounds ovules while gymnosperms do not
Pollination
• Wind, animals, insects, birds, bats • Flowers have characteristics for specific pollinators - nectar attracts animals - wind pollination
Cycads
• about 140 *tropical and subtropical species* - *dioecious* - "palm"like--sometimes called "sago palms"
Gnetophyte
• consist of about 70 species in three diverse and obscure genera 1. Gnetum: tropical vines and shrubs 2. Welwitschia: a *single species* found in desserts of southwestern Africa; *long taproot* grows underground; *two* ribbonlike *leaves extend* and are usually broken and torn by the wind 3. Ephedra: joint fir or Mormon tea; desert shrub of western North America; *produces ephedrine*
Conifers
• includes pines, spruces, hemlocks, and firs - *needle-like leaves* that are long, narrow, tough, and leathery - *mostly evergreen* - *mostly monoecious* - includes the largest and oldest living organisms
Ginkgo
• represented by single extant species, Ginkgo biloba • native to Asia, cultivated worldwide - unique fan-shaped leaves - *deciduous, dioecious*