Plants Flashcards
Advantages of plants living on land:
-greater availability of light
-o2 and co2 diffuses faster in air vs water
Disadvantages of plants living on land
-risk of dehydration
-difficult for gametes to meet(sexual reproduction
Adaptations to living on land
-vascular system
- roots: penetrate soil to anchor plants and reach water sources
- leaves: provide greater surface for photosynthesis
-stems: ridged tissues that raise and support leaves so they are exposed to sunlight
pollen
-water proof structures that contain male gametes
-carried to female plants via wind, insect pollinators, and other animals
seed
-consists of embryo, food, waterproof coat
-remain dormant in favourable conditions like drought, freezing and fire
cell structure of plants:
multicellular, eukaryotes, cell walls have cellulose
mode of nutrition
autotrophs and photosynthesis
(venus flytraps is an autotroph)
no plants can move(locomote)
Nonvascular plants
-absence of or poorly developed vascular tissues for transporting nutrients
-transport of nutrients occurs via diffusion or osmosis
-grow close to ground to obtain water and nutrients
-water necessary for gametes to meet
Seedless vascular plants
-presence of vasscular tissues for conducting nutrients
-reproduce via spores, which requires water for gametes to meet
-vascular tissues have allowed plants to increase in size
Seed bearing vascular plants
-have vascular tissues for conducting nutrients
-reproduce via seeds, allowing plants to reproduce sexually without water for gametes to meet
Gymnosperms
-non-flowering
-less abundant
-produce seeds in cones
-“naked seed”- not surrounded by fruit(conifers,cycads)
Angiosperms
-flowering
-more abundant
-produce seeds in flowers
-seeds have a case or pod(fruit)
-seeds of angiosperms can have one or two specialized structures called cotyledons
Cotyledons are..
structures that are contained in the seed that supply nutrients to the plant embryo
-Monocots
*one cotyledon
*one seed leaf
ex: grassed, bananas, palms
-Dicots
*two cotyledons
*two see leaves
ex: lettuce, tomatoes
Angiosperm reproduction:
-Animal or wind passes pollen to stigma
-Competition among pollen grains to grow pollen tubes fastest to reach ovules in ovary
-Fertilization occurs
-Zygote forms and develops into embryo
-Case covers embryo + food to form seed
-Fruit=mature ovary
-Animals eat fruit and disperse seeds everywhere
Polyploidy in plants
-Almost half of all angiosperms are polyploids, meaning they have more than 2(2n) chromosome sets
-Plants with 3n, 4n or more chromosome sets, are sterile and can only eepodticr asexually
-Sterility caused by polyploidy produced seedless grapes and watermelon
basic needs of plants
1) Make energy(photosynthesis) to make carbs
2) accquire water and other nutrients
3) a method of gas exchange to get CO/ in and O2 out
4) protection(toxins protective structures dehydration
5) reproduction(sexual/asexual….but they can’t move!)
Vascular plant body: Roots and Shoots
-Most plants have the basic design:
* underground root system
*above ground shoot system
-the three main organs(non reproductive) in plants are leaves, stems, roots
-These are made up of dermal, vascular, and ground tissue
Dermal tissue:
-Outermost layers, waxy, protects plant
vascular tissue:
-composed of xylem and phloem
-transport water and nutrients, support plant body
ground tissue
made up of parenchyma, collenchyma, and sclerenchyma
-growth and development
-stores carbs
-support and protects plant body
Meristematic tissue
-tissue made up of undifferentiated cells and found in areas where plant growth take place
-develop into specialize cells and tissues
