chap 22

Starting with the pollen cone at the top, list these terms in the order that they develop on a pine.

1pollen cone 2.microsporangium3. microsporocyte4. microspore5. pollen grain

How many genera are found in the gnetophytes?

3

Bristlecone pines, some of which are the world's oldest living organisms, may live to be about ______ years old.

4,600

There are three genera within the gnetophytes, and these include about ______ total known species.

70

Pine pollen grains possess which of the following characteristics to aid in dispersal?

Air sacs for buoyancy

Native to the White Mountains of eastern central California, which of the following are believed to be some of the world's oldest known living organisms?

Bristlecone pines

The world's tallest conifer is believed to be which species?

Coastal redwood

Which of the following phyla have the appearance of a cross between a tree fern and palm, but are not directly related to either group?

Cycadophyta

Select all the following that are characteristics of Ginkgo seeds.

Enclosed in a fleshy seed coat Nauseating odor

Other than the conifers, which of the following are types of gymnosperms?

Ginkgos Cycads Gnetophytes

Which of the following phyla has both tracheids and vessels in the xylem tissue?

Gnetophyta

Most pines are naturally found north of the equator in coniferous forests, with an exception being the ______ pine.

Merkus

Pines are the dominant trees of coniferous forests, which are found almost exclusively in the ______ Hemisphere.

Northern

the four phyla of living gymnosperms are the ____ (Conifers), ____ (Ginkgo), ____ (Cycads), and ____ (Gnetophytes).

Pinophyta Ginkgophyta Cycadophyta Gnetophyta

Choose all of the following that are phyla of living gymnosperms.

Pinophyta Gnetophyta Ginkgophyta Cycadophyta

Select all of the following that are characteristics of junipers.

Pollen grains lack air sacs Fleshy seed cones

Pine needles (leaves) have several modifications that allow them to survive harsh environments, including which of the following?

Resin canals develop within the mesophyll. Hypodermis is found below the epidermis.

Gymnosperm seeds are borne exposed on the surface of which structure?

Sporophyll

When comparing gymnosperms to ferns, choose all of the following that are true for gymnosperms.

Sporophytes are mostly trees and shrubs. Gametophytes develop inside of sporophytes. Gametophytes are even more reduced in cell number.

True or false: Some pines require fire to open their closed seed cones.

T

Select all of the following that are events during a typical pine pollen grain germination.

Two sperms are produced No antheridium is produced

Which of the following is not a historical use for Eastern white pine trunks?

Waterwheels

After the seed coat hardens, the seed may disperse by which of the following? (Choose all that apply.)

Wings Squirrels

Pine ovules contain a female gametophyte that produce two to six , each of which contains a single egg.

archegonia

About 15 months after pollination in pines, the pollen tube finally reaches the ______.

archegonium

Conifers such as Taxus and Torreya produce ovules that are partially surrounded by a fleshy covering called a(n)

aril

With over 100 species, Pinus is the largest genus of ___

conifers or gymnosperms

The pine pollen tube discharges several cell types, but only one sperm fuses with the egg. The other sperm and remaining cells ______.

degenerate

As gametophyte development is completed within a pine ovule, several archegonia differentiate, and each produces a single, large ______.

egg

The fossils of the first seed plants resembled ______ in appearance.

ferns

The first seed plants appeared in the fossil record about 350 million years ago, and their appearance is very similar to organisms commonly referred to as

ferns or pteridosperms

After pollen grains land on a pine's immature seed cone, a pollen tube slowly grows through the nucellus and several rounds of cell division occur. Rank the cell produced by these cell divisions in the order that they occur, starting with the original cells found in the pollen grain at the top of the list.

generative cellspermatogenous cellssperm cell

Seeds are different from spores because they ______.

have a protective coat and their own food supply

Giant redwoods, such as the General Sherman Tree in Sequoia National Park, are believed to hold the conifer record for ______.

having the most total mass

Pines may survive harsh environmental conditions through modifications such as a hypodermis, endodermis, and resin canals, which are all features of which organ?

leaves

In the United States, the trunks of ___ pines are used for telephone poles, railroad ties, mine timbers, and pulp.

lodgepole

A single megasporocyte within a pine ovule will divide to produce four , of which one will grow into the female gametophyte.

megaspores

In pines, ovules develop on the seed cone scales, and they contain both ______.

megaspores and megasporangia

In the term gymnosperm, gymnos means ___ , and sperma means ___

naked seed

Despite the fact that only one species of Ginkgo remains today, the fossil record indicates Gingko was once widely distributed in the ______ Hemisphere.

northern

In a pine ovule, the ___ is used as a food source for the growing female gametophyte.

nucellus

Gingkoes are called "living fossils" because they are currently found ______.

only where they are grown in cultivation

Seed plants have a significant adaptation in that the female gametophyte is produced inside of an

ovule

The biggest difference between the seeds of podocarps and yews is that ______

podocarp seeds are fleshy-coated and not open on one end

In pines, wind dispersed pollen grains land on immature seed cones and stick to ______.

pollen drops from micropyles

Seeds are a significant adaptation over spores because seeds

protect an embryo and may lay dormant for a long period of time.

In pines, the embryo is found inside which of the following structures?

seed

The integument layer of a pine ovule develops into which part of the seed?

seed coat

Within an ovule, the nucellus is enclosed in an integument, and, later in development, the integument will become the ______.

seed coat

A single pine may produce hundreds of millions of pollen grains, and once the pollen is released, the pollen cones ______.

shrivel and fall off

In gymnosperms, the gametophytes are reduced to just a few cells, and therefore may be enclosed within ______, offering them the advantage of increased protection.

sporophyte structures

The annual rings of which of the following are often fairly wide as a result of rapid growth rates in the woody tissues of pines?

xylem