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*