chapter 18- gymnosperms

gymnosperm

refers to the exposed nature of the seeds

surface of sporophylls

gymnosperm seeds are produced on the ___________ instead of being enclosed within a fruit as in flowering plants

female gametophyte

produced inside an ovule that contains a megasporangium

megasporangium

the ovule contains a

nucellus

what is a megasporangium

integument

what is the ovule enclosed in

sporophyte

mostly trees and shrubs: sporophyte or gametophyte

gametophytes

what is tiny and develop within sporophytes

single

seeds are a results of single or double fertilization in gymnosperms

no

does gymnosperm fertilization require water

dormant state of seeds

seed coat

seed dispersal

seed includes food

4 advantages of seed plants (gymnosperms)

dormant state of seed

what enables seeds to survive cold winters and droughts

seed coat

serves as a barrier against bacterial or fungal decay

seed dispersal

seeds attract seed-eating animals for

food

seeds include _______ for the embryo and germinating seedling

coniferophyta

phylum of conifers

pinus (pines)

what is the largest genus of conifers

bristlecone pines (4600 yo)

what is the worlds oldest known living organism

needlelike, arranged in bundles of two to five leaves

each cluster (fascicle) forms a cylindrical rod if leaves are held together

what are pine leaves like in coniferophyta

hypodermis

where is the hypodermic located in coniferophyta

mesophyll

where do resin canals develop in coniferophyta

tracheids

most gymnosperm wood consists primarily of

soft wood

gymnosperm wood is considered soft or hard wood

mycorrhizal fungi

what is associated with the roots of most conifers

heterospory

are pines (coniferophyta) homospory or heterospory

male strobili

what are pollen cones

papery cones

consist of papery scales arranged in a spiral around an axis

microsporangia

in the pollen cone _________ develops in pairs towards the base of the scales

microspore

in a pollen cone, each ________ develops into a winged pollen grain

microspore

immature male gametophyte of coniferophyta

two prothallial cells, a generative cell, and a tube cell

what does a microspore of coniferophyta consist of

generative cell

what enter the pollen tube and divided (in pollen cone)

sterile cell and spermatogenous cell

what does a pollen cone generative cell divide into

two sperm (no flagella)

what does the sterile cell and spermatogenous cell divide into

mature male gametophyte

if a pollen cone has a pollen tube and two sperm, then it is a

antheridium

what does a pollen cone not form

ovulate cones/female strobili

seed cones

seed cones

consist of woody scales with bracts arranged in a spiral around and axis

bracts

what do seed cones have a maturity

two ovules

what do seed scales bear on its upper surface

nucellus (megasporangium)

what does an ovule consist of that is surrounded by the integument with and opening called micropyle

megesporocyte

what is within the megasporangium

meiosis

what does the megasporocyte undergo: mitosis or meiosis

4 megaspores

what does the megasporocyte produce after meiosis

1

how many megaspores develop into the female gametophyte

two or three archegonia

what differentiates at the micropylar end

pollination

15 months after _______, the tip of pollen tube arrive at the archegonium

zygote→embryo

one sperm unites with the egg forming the ________→_______

female gametophyte

what nourished the embryo

seed coat

what does the integument become after pollination

ginkgophyta

what phylum does the ginkgo belong to

maidenhair tree

common name for gingko

fan-shaped leaves

leaf shape of ginkgo

1 living species

how many species of ginkgo are there

hair-like veins, no midrib or prominent veins

veins of gingko

cycadophyta

what phylum do cycads belong to

cycads

tree with appearance of a cross between a tree fern and a palm

cycads

slow-growing plants of the tropics that have tall unbranched trunks

pinnately

cycads have a crown of largely _______ divided leaves

dioecious

cycads: monoecious or dioecious

zamina pumila

what is the only cycad species native to the us

gnetophyta

what phylum is unique among the gymnosperms in having vessels in the xylem

ephedra

what genus are gnetophyts joint firs in

gnetophytes/ gnetum

phylum and genus that occur in tropics, more vine-like with broad leaves similar to flowing plants

welwitschia, gnetum, ephedra

three genus of gnetophyta

welwitschia

what is confined to temperate deserted of southwestern Africa and only produces two leaves throughout their lifespan

crassulacean acid metabolism (CAM)

what type of photosynthesis does welwitschia have

true sperm conveyor

coniferophyta and gnetophyta don’t produce motile sperm, therefore their pollen tube is a