AP Biology-Plants
Terms
undefined, object
copy deck
- Characteristics Plants Share with Algal Ancestors
-
-chloroplasts with photsynthetic pigments and acessory pigments
-cell walls containing cellulose
-food reserves stored as starch in plastids
-alternation of generations(some but not all) - stomata
- pores in the surface of a leaf designed for gas exchange
- cuticle
- layer of wax secreted by the epidermis to help precent dessication
- Lignin
- woody cell wall component
- Gametangia
-
organs with protective jackets of non reproductive cells
gametes are produced here - vascular tissue
- transports water and nutrients (xylem and phloem)
- Xylem
- dead, usually lignified cells designed for the transport of water, have 2º cell walls. purply/pink
- Phloem
- transport of sugar, associated with companion cells. sieves on ends of cells (blue)
- Characteristcs of nonvascular plants(mosses, liverworts, hornworts)
- have rhizoids, no true roots leaves and stems, antheridium, archegonium. (Byrophyta, hepatophyta, anthocerphyta)
-
1. Byrophyta
2. Hepatophyta
3. Antocerophyta -
1. mosses
2. liverwort( hepat=liver)
3. Hornworts - Characteristics of seedless vascular plants
-
sporophyte is dominant generation, still have flagellated sperm, spores are still main means of dispersing offspring
(Lycophyta, sphenophyta, pterophyta) -
1. Lycophyta
2. Sphenophyta
3. Pterophyta -
1. lycopodium or club moss
2. horsetails or scouring rushes because of silica in cell walls
3. ferns (rhizomes, fronds, sori) -
1.Rhizomes
2. Fronds
3. Sori -
1. underground stem
2. unfurl from fiddleheads
3. spore cases on underside of fronds - Characteristics of seed plants
-
zygotes develop into embryos packaged with a food supply in a protective seed coat, sporophyte generation is dominant, seed is predominant means of dispersing offspring
(Gymnosperms, angiosperms) - Characteristics of gymnosperms
-
naked seed plants, gametophytes develop within sporophyte, have tracheids for xylem and fibers for support
(coniferophyta, ginkgophyta, and gnetophyta) - Coniferophyta
- cone-bearing, pines, firs, spruces, hemlocks, yews, junipers
- Coniferophyta adaptatations for dry conditions
- needle shape reduces water loss, thicker cuticle, stomata in pits
- Coniferophyta have seperate:
- male (staminate-smaller) and female(ovulate-larer) cones
- Coniferphyta are responsible for
- most lumber and paper pulp
- Ginkgophyta
- ginkgos. have seperate male and female trees; females produces a large smelly seed
- gnetophyta
- welwitschia
- Characteristics of Angiosperms
-
covered seed plants, flowering plants, also have gametophytes develop within the sporophyte, have vessel elements for xylem, use pollinators and rely less on wind for seed dispersal
(anthophyta) - Anthophyta
- made up of monocotyledons and dicotyledons
- Monocotyledons
-
parallel veins, one cotyledon, fibrous roots.
(corn, lily, tulips, and grain) - Dicotyledons
-
branching veins, two cotyledons, taproots (extened deeper)
oak, rose, daisy, larger trees, beans - Sepal (flower part)
- protects bud
- petals (flower part)
- protect reproductive organs and attract pollinators
- stamen (flower part)
- made up of filament and anther
- filament (flower part)
- long for easy access
- anther (flower part)
- contains pollen
- Carpel/pistil
- made up of stigma, style, and ovary
- Stigma
- sticky for pollen grains to land on it
- Style and ovary
- pollen lands and tube nucleus forms tube down style style and sperm nucleus fertilizes each egg.
- Ovule
- seed -> seed begins to thicken and ovary becomes fruit.
- Evolutionary trends of plants
- number of floral parts have become reduced, floral parts have become fused, symmetry has changed from radial to bilateral, ovary is better protected having dropped lower, coevolution between flower and pollinator
- Fruits
- Agregate, multiple, and fruit modification
- agregate fruits
-
several ovaries that are part of the same flower
raspberries - multiple fruits
-
one that develops from several separate flowers
pineapples - fruit modifications
- seeds within fruits that are shaped like kites or propellers to aid in wind dispersal, burrlike fruit that cling to animal fur, edible fruit with tough seeds that pass through the digestive tract
- Impact of plants
- transformation of atmosphere and climate, decrease CO2, agriculture, fibers, medication, perfume, decoration
- Reproductive adaptations of seed plants
- reduction of the gametophyte, origin of the seed- embryos with food source and now is primary means of dispersal (as opposed to spores), pollen
- two types of sporangia spore-producing structures in seed plants
- mega(egg) and micro(sperm)
- Meristem (plant structure and growth)
- tissue that is undifferentiated and is actively dying
- 3 Primary meristems (plant structure and growth)
-
protoderm(dermal), procambium (vascular> xylem-water and minerals, phloem-sugars)
ground meristem (ground tissue-filler) - parenchyma (plant structure and growth)
- thin with flexible walls. frequently contain plastids
- 3 concentric layers of roots(plant structure and growth)
- epidermis, cortex, and vascular cylinder (stele)
- Epidermis(plant structure and growth)
- absent of very thin cuticle (root hairs)
- Cortex(plant structure and growth)
- mostly parenchyma. usually specialized for food storage. (made of endodermis and casparian strip)
- Endodermis (plant structure and growth)
- innermost layer which is compact with no space between cells
- Casparian strip)plant structure and growth)
- band of wax that surround cells of endodermis. regulates what gets into and out of the vascular cylinder
- Vascular Cylinder(plant structure and growth)
- made of pericycle and pith
- pericycle (plant structure and growth)
- layer of cells inside endodermis that gives rise to lateral roots. vascular tissue (dicot and monocot)
- dicot (plant structure and growth)
- xylem is a cross with phloem bundles in between
- monocot
- xylem and phloem bundles are in a ring.
- pith
- filler area in middle of stem or root (in monocot roots and dicot stems)
- Root growth
- primary, secondary and radicle
- Primary root growth
- up and down through use of apical meristem tissue
- Secondary root growth
- out to side through use of lateral meristem tissue called cambiums (vascular and cork)
- Radicle root growth
- with root cap to protect apical meristem tissue
- dicot(patterns of growth)
- taproot with lateral and branching roots
- Monocot patterns of growth
- fibrous or adventitious. aerial or prop roots (in bogs or swamps with no space for water and minerals)
- stems are for
- support and transport
- Stem structure
- collenchyma and sclerenchyma
- collenchyma
- have primary cell walls with thick corners, glue like
- sclerenchyma
- both have lignin in cell walls, have secondary cell walls, dead at maturity, grow when primary growth is done. (fibers and sclereids)
- Fibers in stem structure
-
elongated elastic bundles and strands.
flax, hemp, jute, and raffia - Sclereids in stem structure
- common in stems and seeds, nuts, fruit
- Vascular Tissues in stems
-
arrangement is ring in dicots and scattered bundles in monocots.
Phloem and Zylem - Phloem in vascular tissue of stems
- Transports sugars, sieve tubes, sieve tube members, companion cells, p-protein.
-
1. Sieve tubes
2. Sieve tube members
3. companion cells
4. p-protein -
1. in gymnosperms and dead at maturity
2. in angiospemrs and alive at maturity. frequently associated with companion cells.
3. perform normal cell functions
4. callose, plugs up plates in response to injury - Xylem in stem vascular tissue
- Tracheids and vessel members
- Tracheids( in xylem in vascular tissue of stems)
- long, thin with tips that overlay (more primitive) have pits with no secondary walls
- vessel members (in xylem in vascular tissue of stems)
- short and wide with perforations. most are thick with lignin in thick secondary walls
- Variations in vascular tissues of stems
- runners, rhizomes, creosote, vegetative propagation
-
1.runner
2. rhizomes
3. creosote
4. vegetative propagation -
1. along the soil surface, strawberries
2. stems just under the soil, bamboo and potatoes
3. form a ring
4. using stem cutting and root hormone to grow things like seedless grapes pinneapples and bananas - Secondary growth of vascular tissues in stems
- Vascular cambium, cork cambium and heartwood
- Vascular Cambium
- between xylem and phloem(adds secondary xylem and phloem) xylem gets added to inside and phloem gets added to outside
- Cork Cambium
- produces new epidermis (because old gets stretched and torn) the CC moves inward as more is added to the outside
- Heartwood
- at the center, usually consists of dead parenchyma cells
- Leaves consist of
- cuticle, lower and upper epidermis, palisade parenchyma, spongy parenchyma, mesophyll, and stoma, vascular bundles
-
1. cuticle
2. upper and lower epidermis
3. palisade parenchyma -
1. secreted by epidermis, made of cutin
2. clear cells, secrete the cuticle
3. densley packed columnar cells loaded with chloroplasts -
4. spongy parenchyma
5. mesophyll
6. stoma -
4. loosely packed so that the leaf can store carbon dioxide without water loss
5. spongy palisade parenchyma together; where photosynthesis takes place.
6. with guard cells. stoma is the hole that allows gas exchange and guard cells open and close the opening. stomata are usually more abundant on the underside of the leaf - Purpose of roots
- anchor plants, absorb and conduct water and nutrients, store food
- Types of roots
- taproots, fibrous roots, root hairs, adventitious roots
-
1. taproots
2. fibrous roots
3. root hairs
4. adventitious roots -
1. one large vertical root with smaller secondary roots, providing firm anchorage
2. primarily in monocots, a nat of threadlike roots spread out below the surface of the soil
3. tiny hairs on smaller roots that enhance absorption ability
4. roots arising above ground from stems or leaves - External parts of shoots/stems (Roots)
- Nodes, internodes, axillary buds, terminal bud
-
1. nodes
2. internodes
3. axillary buds
4. terminal buds -
1. points where leaves are attatched to stems
2. stem segments between nodes
3. embryonic side shoot found in the angle formed by each leaf and the stem
4. the bud on the end of the shoot tip, usually has developing leaves - Growth of shoots/stems in roots
-
primary-vertical growth as a result of apical meristem division
and secondary-lateral growth as a result of cambium cell division - Leaves
- flattened blade joined to the stem by a petiole(except monocots
- Cell specifics:(Structural adaptations of plant cells)
- parenchyma, collenchyma, sclerenchyma, xylem, phloem
- Parenchyma
- least specialized where the cell walls are thing and flexible (bloblike)
- Sclerenchyma (Structural adaptations of plant cells)
- function in support, have thick secondary walls strengthened by lignin (fibers and sclereids)
- Fibers in sclerenchyma (Structural adaptations of plant cells)
- long slender tapered cells occuring in bundles( jute rope, and raffia)
- Sclerieds in sclerenchyma (Structural adaptations of plant cells)
- shorter, irregular shaped cells (in pears, the gritty stuff)
- Xylem (Structural adaptations of plant cells)
-
water-conducting cells that have seconday walls (in rings and spirals) and are dead at maturity
(tracheids and vessel elements) - Tracheids in xylem (Structural adaptations of plant cells)
- long thin and tapered (like thin pipes in a house)
- Vessel elements in xylem (Structural adaptations of plant cells)
- wider, shorter, and thinner walled, aligned end to end (like big PVC pipes)
- Phloem (Structural adaptations of plant cells)
-
food-conducting cells that are alive at maturity but lacking most organelles
(sieve tube members and companion cells) - sieve tube members in phloem (Structural adaptations of plant cells)
- wide tubes with a colander-like plate at the end of the cells
- companion cells in phloem (Structural adaptations of plant cells)
- because sieve tubes lack nuclei, these perform the jobs necessary for the other cells' lives
-
Dermal tissue-epidermis
(Structural adaptations of plant cells) - single layer of tightly packed cells covering and protecting young parts of the plan.
- Vascular tissue in the organization of cells (Structural adaptations of plant cells)
- the pipes of xylem and phloem
- ground tissue (Structural adaptations of plant cells)
- predominantly parenchyma with some collenchyma and sclerenchyma, functions in photosynthesis, storage and support