Plants Flashcards
Endosymbiotic Theory and the evidence
states that a prokaryote engulfed a mitochondria / chloroplast and lived in symbiosis; this evidence is that the membrane bound organelles have their own DNA
Examples of membrane bound organelles
Mitochondria, chloroplasts, vacuoles, ribosomes, endoplasmic reticulum
Types of Plants
- Nonvascular Plants (eg. Peat moss, liver/horn warts)
- No vascular tissue
- Water/food move via osmosis/diffusion
- Must be near water and small - Spore-producing Plants (eg. Ferns, horse tails, club mosses)
- Gymnosperms (eg. Pine tree)
- Angiosperms (eg. Roses, apple trees)
Alternation of Generations cycle
- Gametophyte (n) undergoes mitosis and makes egg (n) or sperm (n)
- Fertilization occurs to form a 1-celled zygote (2n)
- Zygote undergoes mitosis and turns into an embryo (2n)
- Embryo grows into a sporophyte (2n) via mitosis
- Sporophyte undergoes meiosis to form spores (n)
- Spores grow via mitosis into a gametophyte (n)
Gametophyte def
Haploid plant generation that produces haploid gametes (2 types; egg and sperm)
Sporophyte def + fun fact
Diploid plant generation that produced haploid spores through meiosis
the sporophyte grows out of the gametophyte body. The male gametophyte sperm fertilizes the female gametophyte and the sporophyte grows off of it.
Plant Reproduction: asexual
- Non-Vegetative Propagation: roots, stems, and leaves can be modified into new plants
- Artificial Propagation: take desired tissue (scion), and cut and paste onto the parent body (must be same species)
Plant Reproduction: sexual for seedless plants
Reproduction in a wet environment (water is required for the sperm to swim from the male gametophyte to the eggs
- Non-vascular: dominant gemetophytes plant (mosses)
- Smaller sporophyte depends on the gametophyte for food and support - Spore Producing: domainant sporophyte plant (ferns)
- Large leafy part is the sporophyte
Plant Reproduction: sexual for seed plants
Reproduction in a dry environment
- Gymnosperms: unprotected (naked) seeds
- Angiosperms: protected (seed coat) seeds
Monocot traits
of embryonic seed leaves: 1
Organization of vascular bundles in roots/stems: roots = ring, stem = scattered
Leaf venation: Parallel
Number of flower parts: 3 parts or sets of 3
Presence of wood (secondary growth): No
Root system: Fibrous
Examples: Asparagus, onions, grass, oats, wheat, corn
Dicot traits
of embryonic seed leaves: 2
Organization of vascular bundles in roots/stems: roots = star formation, stem = distinct ring
Leaf venation: Palmate or Pinnate
Number of flower parts: 4 or 5 parts or sets of 4 or 5
Presence of wood (secondary growth): Yes
Root system: Taproot
Examples: Oak trees, strawberries, beans, legumes, carrots, dandelions
Seed Dispersal methods
- Wind (milkweed, dandelion)
- Water (coconut seed)
- Animal fur (cocklebur seed)
- Being eaten (birds eat fruit with hard seeds that can’t be digested; when eliminated, can germinate in suitable soil)
Angiosperm Life Cycle
- Pollen lands on the stigma. Germination occurs
- Stigma secretes nutrients which pollen absorbs
- Pollen’s cytoplasm extends to ovary via microphile
- 1 of Pollen’s 2 nuclei divides into 2 “sperm nuclei”
- 1 sperm nucleus fuses with ovum (egg) to produce zygote
- Other sperm nucleus fuses with ovule’s 2 nuclei to form “triploid endosperm”
- Zygote grows into embryo then into sporophyte
- Ovule develops into a seed and the ovary dries to form capsule for the seed
- Cycle repeats!
Stigma def
female reproductive part
Pollen def
sperm produced in anther; consists of 1 tube cell and 2 nuclei cells
Micropyle def
tiny opening in the ovary
Ovum def
female reproductive egg cell
Ovule def
female part that develops into a seed
Endosperm def
stores nutrients for the developing seed
Radicle def
minature root
Plumule def
small shoot
Cotyledons def
seed leaves
Fruit def
fertilized ovary of a flower
Simple Fruits def
fruits that develop from a single ovary in a single flower (tomatoes, plums, pears)
Aggregate Fruits def
fruits that develop from many ovaries in a single flower (raspberries)
Plant organs + evolution
- In a plant, they are the stems, roots, and the leaves
- Made up of specialized cells and tissues that have a particular function in the organism
- All structures have evolved over time to do the function optimally
Stems: function
- Structural support for leaves, flowers, seeds, fruits
- Transport of water and dissolved minerals from the root + carbohydrates from the leaves to the rest of the plant
- Some stems have chloroplasts and carry out photosynthesis (green stems)
- Some stems can store food
Stems: types
- Herbaceous Stems
- Green, soft, flexible
- Produced by plant in first year of growth; after the stem may remain herbaceous or develop into a woody stem
- Causes primary growth - Woody Stems
- Brown, thick, hard, tough
- Consist of primary + secondary tissue
- Most of the tissue is secondary and produced by lateral meristems
- Causes secondary growth
- Produced only in second and subsequent years of trees, shrubs, some vines
Primary Growth def + process
All cells + tissues are produced by the apical meristems in the tips of the root and stems
- Tip is rapidly dividing
- Elongation of the cells occur
- Pushes cells upward or in the case of the root, down!
Vascular Bundles def
Bundles of xylem (center) or phloem (outside) and are surrounded by supporting tissue (aka ground/parenchymal tissue)
Herbaceous stems can be found in…
- Monocots
- Vascular bundles are scattered throughout stem
- No vascular cambrium; does not grow wider - Herbaceous Dicots
- Vascular bundles form a ring around the stem
- Vascular cambium is only found in the rings of the vascular bundles to make new vascular tissue for secondary growth
Woody stems can be found in…
Woody dicots only
Secondary growth process
- Vascular bundles grow to make a ring around the woody stem
- Consist of a thin layer of tissue called vascular cambrium (type of meristematic cell) that founds between xylem and phloem and allows plants to develop woody stems aka bark
- Grow in width
- Produced new layer of vascular tissue referred to as secondary xylem and secondary phloem
Types of Woody Stems: Sapwood
- Young, functional xylem that transports water and dissolved minerals
- Growth of new xylem results in a layer of sapwood or annual rings being formed
- Age of tree
- Weather during the year xylem were produced
- Width of annual rings determine length of growing season