LESSON 9: D9 - Introduction to Plants Flashcards
Why do some have allergies?
- Some peoples immune systems see allergens such as Pollen as threaths and fight it off
- White blood cells attach to pollen, releasing inflammatory chemicals
-This sitmulates nerve cells and causes mucous membrans to leave fluid
Who atre plants thought to orginate from?
Charophytes
-A group of protists green algae
Characetristics of a plant?
-Multi-cellular
-Eukaryotic
-photosyntheic
-Cell wall of celluose
-Immobile (sessile)
- Reproduce by alteration of generations
How dpes alertnation of genes work for plants?
- They alternate between a diploid sprophyte generation and a haploid gametophyite generation
Sporophyte
Asexual phase
Gametophyte
Sexual phase
Types of Plants: Bryophytes
- Mosses are the most familiar group
- Evolved many features which make other terrestrial plants successful
- no vascular system
- Instead they depend on simple diffusion, osmosis and active transport to survive
-Also have rhizoids- not true roots
This also accounts for their limited capacity for absorption and lack of anchorage
Mosses: Pioneer Plants
are often the first to establish themselves on previously uninhabited area
-As they die and decompose, they enhance the environment
i.e. provide organic matter that enhances the soil and facilitates other plant growth
Just because soemthing is called a moss or a fern does it mean it classifies as so?
No
Peat Moss
Pioneers in Ecosystems
Used in gardening
Used as a fuel in Europe and Asia
Can be chemically altered to form coal
Can be used as antiseptic
Used to mop up oil spills
Absorbent - so was used as surgical dressings in WWI, diapers for babies and in feminine hygiene products
Types of Plants: Tracheophytes
Ferns are tracheophytes- plants that have a vascular system
Earliest vascular plants to evolve
Ferns are the most well known example
How do ferns help our ecosystems?
Play an important role in ecological succession (i.e process of change in the species that make up an ecological community over time)
-Pioneer plants
Fiddlehead Ferns
-young curled fronds of young ferns that are harvested as a vegetable
-Good for you
Types of Plants: Spermatophytes
Seed plants are called spermatophytes
-They have roots, stems, and leaves
-Most recently evolved
-Reproduction NOT dependant on water
-They have a seed which contains a plant embryo
What are subdivisons of tracheophytes
Vascular plants
Types of Spermatophytes: Gymnosperms
pines, junipers, spruces, cedars and other cone-bearing plants
-thin- needle like leaves
Help plant survive harsh dry, hot and cold weather
-Needles covered in a hard waxy cuticle
-Deep penetrating roots
Yew
Paclitaxel (a well known natural source cancer drug) can be isolated from the tree bark
Types of Spermatophytes: Angiosperms
- flowering plants
-All are tracheophytes
-Because they have vascular tissue
-All will have flowers and fruit for reproduction
Rice
Rice is the seed of certain grass species
Steps of Angiospern plant reproduction
-Pollunators brush agsint anters and pick up pollen
- When pollenatar brushes pollen from another flower onta stigma, the flower is pollinated
- Next the sperm joins a egg
- Pollen grains consist of 2 types of cell tube cells and generative cells
-Pollen grain lands on stigmas, uses the tube cells to burrow down a pollen tube from the stigma through the style to the inside area of the ovary
-Generatives cell which is inside the ovary will divide into 2 sperm cells
-From there, the sperm cells target an ouvle inside the ovary
- Each ovule has the potenial to devlope into a seed if fertilzed
-inside the ovule there is an egg cell and 2 polar nuclei
-one sperm cell fertizlies the egg, which forms a zygote
-the second sperm join with the 2 polar nuclei, whic devlopes Endosperm.
-ovary ripens and turns into fruit
-seeds trvael far from parent so they do not compete
what devlopes when the second sperm join with the 2 polar nuclei
Endosperm
Double fertilzation
the second sperm join with the 2 polar nuclei, whic devlopes Endosperm.
Reproduction with gymnosperms
Example, Pine trees
-Pollen from males cones are released
-female cones may pick up on the pollen, the pollen fertilizes in the ovule
-This makes a seed
A plant in the diploid stage is called a..
sporophyte
What do haploid cells in plants form?
asexual spores
Alertration of generation in plants
-As the haploid generation begins,
the spores grow into gametophyte individuals
- Th e gametophytes mature, then produce haploid sex cells—gametes.
- Th ese gametes undergo fertilization to form diploid
zygotes. - Th e zygotes grow into sporophyte individuals, and the cycle continues.
cuticle
a waterproof, waxy coating
produced by the epidermis of most plants
stoma
a small opening in the epidermis
of a plant that allows gas exchang
bryophyte
a small seedless plant that
lacks vascular tissue
gemma
a small clump of haploid
photosynthetic cells produced in little cupshaped structures on the gametophyte
plant; dispersed by splashes of rain to
grow into another gametophyte plant
antheridium
the specialized structure
on a gametophyte that produces sperm
archegonium
the specialized structure
on a gametophyte that produces eggs
sporangium
the structure in which
spores are produced
lignin
an important structural compound
found in the vascular tissues of plants; it is
responsible for the strength of wood
lycophyte
a seedless vascular plant; club
mosses are examples of lycophytes
pterophyte
a seedless vascular plant;
ferns are examples of pterophytes
rhizome
a horizontal underground stem
Gymnosperms and angiosperms are…
seed plants
gymnosperm
a vascular plant that
produces seeds in special structures
called cones; gymnosperms are a major
plant group
cone
in plants, the reproductive structure
of a conifer; produce either pollen or ovules
angiosperm
a plant that produces
fl owers;
cotyledon
a structure in the seeds of
fl owering plants that stores nutrients
steps to alteration of generation
- Starts with sporophyte. The sporophyte generation is diploid(two copies of each kind of chromosome)
-meosis starts to take place meaning the diploid cell divided because of meosis and produces haploid spores
-The spores are haploid, the haploid spore then goes through mitosis and divide which results in gametophye generation
-Gametophye generation is haploid. The haploid gametophye produces gametes which are your sperm and egg
-sperm and egg are both haploid. During fertilzation the sperm fertilzes the egg and a diplod zygote is produced
-Diplod zygote divideds by the process of mitosis which produces a sporophyte
Mitosis
One cell dividing and producing two gentically identical daughter cells
meiosis
one cell divides and produces either one cell or more with some si milar chromosomes
