Lecture 2 -- Plants Flashcards
compare the life cycle of animals and plants
animals: (2n) zygote – adult – meiosis (n)– egg/sperm – fertilization – zygote.
plants: (n) spores – germinates – gametophyte – egg/sperm – fertilization – (2n) sporophyte – meiosis – spores.
spore
a single cell that can divide to produce a multicellular organism, often with a protective coat.
gamete
single cell that unites with another gamete to produce a diploid zygote
the 4 division of land plants we are looking at
Conifers (coniferophyta), Ferns (pterophyta), Mosses (Bryophyta), and Angiosperms (Anthophyta)
which divisions are seed plants
coniferophyta and anthophyta (conifers and angiosperms)
characteristics of mosses (Bryophyta)
- 15000 species
- low growing
- confined to damp areas
- swimming sperm
- no vascular tissue
- no true leaves
- homosporous
- gametophyte dominant
Moss life cycle
(n) spores – male/female gametophyte – antheridium/archegonium (sperm/egg) – rain – sperm travels down archegonia and meets egg – fertilization – (2n) within archegonium is zygote – young sporophyte (IN ARCHEGONIUM) – sporophyte projections on female gametophyte – sporangium – meiosis – spores
in the moss cycle, what phase is dominant, and what is dependent on what
the haploid phase (gametophyte) is dominant, and the sporophyte depends on the gametophyte.
After mosses, what major step of evolution
vascular tissue
what does vascular tissue give to a plant
supports and supplies.
supplies organism with nutrients and water (xylem and phloem) and allows plants to grow tall and to spread.
characteristics of ferns (Pterophyta)
20000 species
appeared 400 MYA
vascular tissue (xylem + phloem, supports, supplies)
swimming sperm
sporophyte dominant
homo or heterosporous
life cycle of ferns
(n) spore – young gametophyte – mature gametophyte (has both male and female functions) – archegonium/antheridium (sperm/egg) – fertilization – (2n) – within archegonium, zygote – new sporophyte (gametophyte stays, but withers away after a moment) – mature sporophyte – sporangium – meiosis – spore
cinnamon fern
2 kinds of leaves, 1 for photosynthesis and 1 for sporangia production.
its spore release is like an opening of the clam, fastest movement.
homospory
1 size spore from meiosis
heterospory
2 size spore from meiosis
for mosses, how are gametophytes male and female
the environment is what determines whether it is a male or female gametophyte.
homosporous spore production
sporangium – meiosis – single type of spore – bisexual gametophyte – egg/sperm (this is in all mosses and most ferns)
heterosporous spore production
[megasporangium – meiosis – megaspore – female gametophyte – egg]
[microsporangium – meiosis – microspre – male gametophyte – sperm] (some ferns and all seed plants)
megaspores
big spores
microspores
little spores
where are micro and mega spores made
on two different sporangium
male vs females in reference to spore size
male = small spores
female = big spores
what do seed plants have
seed and pollen
seed
complex structure made up of three parts, embryo, nutrition, and seed coat.
how does a seed develop
from ovule (immature seed) – site of female meiosis, therefore has female characteristics.
Ovule (conifer) Before meiosis in megasporangium
micropyle (opening for pollen), integument, megasporangium.
ovule (confier) after meiosis in megasporangium
integument, single functional megaspore – through division will become a megagametophyte, megasporangium
how many megaspores does the megasporangium make
4 megaspores but only one lives
picture of an unfertilized ovule
megaspore, megasporangium, pollen grain, micropyle, and integument
picture of fertilized ovule
female gametophyte, egg nucleus, discharged sperm nucleus, pollen tube, male gametophyte (pollen)
picture of mature ovule (gymnosperm seed)
seed coat, embryo, megagametophye (food)
pollen
mature male gametophyte, few cells in size, and contains sperm.
characteristics of conifers (coniferophyta)
550 species
reproductive organs in CONES
heterosporous
microgametophyte = pollen
megagametophyte – within ovule, makes egg, provides nourishment to embryo.
conifer life cycle
male part: seeds – seedling – mature sporophyte – (pollen cone) – microsporocyte – microsporangium – meiosis – pollen gran/sperm travels to megagasporangium (micropyle)
female part; seeds – seedling – mature sporophyte – (ovulate cone) – ovule – megasporocyte – megasporangium – meiosis – surviving megaspore – archegonium/ female gametophyte
both parts: pollen swims down pollen tube – meets egg – fertilization – embryo – seeds.
what will pollen due in the coniferous life cycle
it will sit and wait a year or two waiting to fuse with the egg until it is ready to do so. (jack pine)
what is a sporophyte
a diploid cell that undergoes meiosis
in coniferous plants, what is the seeds nutrition
megasgametophyte
coniferous gametophytes summary
megagametophytes: makes egg in archegonium, and nourishes embryo
microgametophytes: are pollen and makes sperm.
