Exam 7
Terms
undefined, object
copy deck
- Lateral shoot (branch)
- an offshoot of the stem of a plant
- Leaf
- an outgrowth of a plant that grows from a node in the stem. Most ????? are flat and contain chloroplasts
- Axil
- the angle between the upper side of the stem and the leaf, branch, petiole
- Examples of dicots
- water lily, rose, violet, sunflower
- Examples of monocots
- iris, corn, wheat, camas
- Flower
- the reproductive part of a plant
- Tropisms
- plants response to environment; Including photo???? and geo?????
- Brassionosteroids
- Inhibit root growth, slows leaf loss, grows the xylem, Similar to cholesterol and sex hormones of animals
- Abscisic Acid
- Promotes dormancy, blocks growth of stems, Stimulates the closing of stomata
- Heartwood
- the core of the trunk, which contains very strong, dead tissue that supports the tree
- Outer bark
- the protective outer layer of the trunk
- Style
- formed from the ovary wall. The tip of the ??? carries the stigma to which pollen grains attach. Part of the pistil that separates the stigma from the ovary
- capillary action
- the adhesion between h20 and the xylem tube walls, many small xylem tubes better than less big ones
- Gibberellins
- Stimulates rapid stem elongation (incl phloem cells), Inhibit formation of roots, terminates dormancy of seeds & buds, and Induces biennial plants to flower during 1st year of growth. Commmercially sprayed gibberellins on fruit to make the fruit grow larger
- Cork
- the name for phloem (inner bark) after it has died.
- Petals
- the inner ring of the flower leaves
- Flower
- the reproductive unit of angiosperms
- Sepals
- the outermost ring of the flower leaves
- Root
- plant structure that obtains food and water from the stores energy provides support for the plant. 3 types: Tap ???, aerial ???, fibrous ???
- # of essential nutrients
- at least 17 different essential nutrients
- Ground tissue
- most extensive system, gives the plant a body (functions as support, storage, and photosynthesis), comes in 3 types (collenchyma, parenchyma, sclerenchyma cells)
- epidermis -> root cortex
- 2 routes, apoplastic route then symplastic route
- Cytokinins
- promotes cell division; EG: Kinetin Generates plant growth, Breaks seed dormancy, Expends and slows down ageing of leaves
- Double fertilization steps
- A pollen grain (sperm) must land on the style. Given that it's the right species (chemical including calcium to help determine if the pollen will be accepted).A pollen tube develops and travels down the style. The generative cell divides down the pollen tube into the embryo sac. One sperm fertilizes the egg --> zygote. The other sperm fuses with the 2 polar nuclei --> 3n nucleus = Endosperm. The endosperm is the nutrition for the fertilized egg
- Phototropism
- A plants response to light, usually by growth; gravity pulls Auxins lower on one side, growth is inhibited on that side, the other side goes against gravity, towards the sun
- Long Day plants
- Clover, Spinach, Radish, Iris | exposure to shorter nights (~ 8 hrs) causes them to flower
- reasons for transpiration
- osmosis, capillary action, cohesion tension theory
- Tissue systems
- dermal, vascular, ground
- Petiole
- a leaf stalk
- Flower stalk
- the structure that supports the flower
- Stem
- (AKA the axis) the main support of the plant
- osmosis
- there is a higher concentration of minersls inside the root, so H20 goes into the root to balance this
- Collenchyma cells
- living, flexible support in stems and leaves, found just inside the epidermis
- translocation
- the movement of sugar through the plant; starts with h20 + minerals at roots going up to leaves through xylem. Source cells make sugar (sucrose) and add it to the H20 moving down through phloem where sucrose gets dropped off in roots and the pure h220 just goes back up the xylem.
- Parasitic plants
- they can't survive alone without the plant; mistletoe
- Xylem
- dead cells moving water and minerals up to leaves, composed of trachea cells and vessel elements.
- Carnivorous plants
- they need to feed on other plants or animals/insects. Soil is so poor that they must eat other animals / insects for the nutrients.EG: Pitcher plant, Venus fly trap
- Gametophyte
- plant sex cells
- Nitrogen
- essential nutrient comes from bacteria in soil. ++==++ The nitrogen fixing bacteria take the N2 and turn it into NH3 (ammonia) and in the soil, it gains another H to become NH4. Certain plants (peas - legumes) have nodules on their roots where this bacteria resides.
- Carpel
- the female flower organ, consisting of the seed bearing ovary, stigma, and style
- symplastic route
- cell to cell movement via plasmodesmata (tubes between cells)
- Phloem
- live cells moving things like sugar down to root cells, consist of sieve tube members
- Characteristics of dicots
- two cotyledons, flower in groups of 4 / 5, leaf veins form a network pattern, pollen grains often have 2 spores, vascular bundles arranged like a tree (ring shaped, not scattered)
- Auxins
- promotes cell growth; makes cells grow larger; The first that scientists discovered; Produced in apical buds - that's why it helps with apical dominance and tropisms
- Stigma
- the sticky surface at the tip of the style to which pollen grains attach.
- Ethylene
- Stimulates the ripening of fruit, Causes loss of leaves during seasonal changes. Released during times of stress
- Auxiliary bud
- a bud that develops in the axil
- Cambium
- a single layer of living cells in the trunk that is located between the sap wood and the inner bark
- Characteristics of monocots
- one cotyledon (in-seed leaf), flowers in groups of 3, veins of leaf are parallel, pollen grains often have one spore vascular bundles scattered throughout.
- Day neutral
- Tomatoes, rice | photoperiod does not matter.
- apoplastic route
- between the epidermal cells until reaching the Casparian strip, then through the endodermic cells
- Female Gametophyte
- Ovules produced in ovary, (2n) megasporocyte --(meiosis)--> 4n megaspores, Only one megaspore will survive (just like with humans), Goes through mitosis 3x to produce 1 large cell with 8 haploid nuclei
- Vascular tissue
- used for transport through plant (in every part of plant), arranged differently in mono/dicots, has Xylem and Phloem
- Short Day plants
- Chrysanthemum, Poinsettia, Strawberry | Exposure to Long nights ~10 hrs stimulates flowering
- cohesion tension theory
- causes most of the xylem movement, as H20 evaporates from open stomata, water is pulled up capillaries to replace what was lost
- Terminal bud
- a bud located at the apex of the stem. Has a special tissue (called apical meristem) consisting of cells that divide infrequently.
- Ethylene Inhibitors
- These hormones inhibit ethylene, Cause dormancy of lateral buds and seeds during autumn and winter, break down gradually over time and sometimes get destroyed in the cold weather.
- Tap root
- the main root of some plants; the ?????? extends straight down under the plant
- Internodes
- the area of the stem between any two adjacent nodes
- Sclerenchyma cells
- dead at maturity and found in non growth areas (they act as support)
- Stamen
- the male organ of a flower. Filament, anther, pollen sac
- Route of H20 from soil to leaves
- Soil -> epidermis -> root cortex -> xylem
- Node
- the part of the stem of a plant from which a leaf, branch, or arterial root grows; each plant has many of theese
- The ratio of Cytokinins to Auxins
- Higher levels of Auxins = root formation | Higher levels of Cytokinins = buds grow into stems
- Root cap
- a structure at the tips (ends) of roots. It covers the apical meristem of the root
- Inner bark (phloem)
- the layer of the trunk through which the tree's food (produced sugars) flows
- Secondary growth
- elongation of branches and thickens leaves (plant gets bushier)
- Photoperiodisim
- Similar to the circadian rhythm in humans, Responsible to changes in the length, Short day vs long day plants
- Florigen
- Leaves detect the photoperiod and send chemical messages via
- root cortex -> xylem
- once the h20 has gone past the epidermal cells, it moves into the xylem by way of the cortex cells
- Geothrophisim
- plants response to gravity. Positive geothrophisim - roots growing downwards; negative geothrophisim - plant growing normally, away from gravity
- Dermal tissue
- external most tissue, covers entire plant (for protection); guard cells (stomata) also count
- Parenchyma
- the typical (most abundant) plant cell, dominant for ground tissue, in leaves called Mesophyll cells that allows CO2 + O2 to pass through, store pigments and are flesh of fruit.
- Soil -> epidermis
- water is pulled into the roots via osmosis, the epidermal layer does not have a cuticle to stop water.
- Primary growth
- elongation of roots and shoots (taller)
- Male Gametophyte
- created within the pollen sac (sporangia) which are in the anther. (2n) microsporocytes --(meiosis)--> 4n haploid microspores --(mitosis)--> generative cell + tube cell. The tube cell encloses generative cell and produces pollen tube during fertilization