Test 1 Flashcards
Haplodiplontic life cycle
life cycle that alternates between a haploid phase and a diploid phase
Sporophyte
- diploid phase in haplodiplontic life cycle
- produces spores through meiosis
- remains attached to gametophyte for nutrition
Gametophyte
- haploid phase in haplodiplontic life cycle
- dominant/larger
- produces sperm and eggs (gametes) through mitosis
Thallus
- the plant body of bryophytes
Bryophytes
- liverworts
- mosses
- hornworts
- most primitive group of terrestrial plants
Functions of Rhizoid
- water transport
- adhesion to surfaces
Antheridium
- male sex organ that produces sperm
- located on male thallus
Archegonium
- female sex organ that produces eggs
- located on female thallus
Zygote
- fertilized egg
- divides and matures in the archegonium to produce the sporophyte
Sporangium
- structure that produces and stores spores
- located on thallus
Dioecious
- having the male and female reproductive organs in separate individuals
- gametophytes and sporophytes
Where does meiosis occur?
- the sporangium
Characteristics of algae
- multicellular autotrophs
- no roots
- no support tissue
- no desiccation resistance
Characteristics of plants
- multicellular
- autotrophic
- cell wall of cellulose
- chlorophyll a & b
- haplodiplontic life cycle
What is the difference between plants and algae?
In plants, the zygote and embryonic sporophyte are supported by the parental gametophyte
Where do algae tend to live?
- near the shoreline
What are algae in competition for?
- light
- nutrients
- space
- CO2
Where do algae get their nutrients from?
the land
Barriers inhibiting movement onto land
- desiccation
- nutrients and water are localized in the ground
- stomata
Solutions to desiccation
- sporopollenin
2.waxy cuticles - stomata
Sporopollenin
- organic molecule
- completely water proof
- surrounds the spores and allows dispersal
waxy cuticles
- reduces water loss
- reduces the uptake of CO2 and release of O2
- the drier the environment the thicker that cuticle
Stomata
- controls gas exchange
- responsible for water loss
Solution to localized water and nutrients
- grow flat
- vertical growth
What is required for vertical growth?
a) transport of H2O and nutrients
b) structural support
c) thick hollow dead cells
- hydroids: dead thick cell wall, limited vertical growth, limited transport
d) tracheids
- much thicker cell wall containing a molecule called lignin
- non-compressible and rigid
e) vessel elements
- shorter, thicker, and stouter than tracheids
- more lignified
- more structural support
- occurs in the angiosperms
Solution to no water for reproduction
- mosses, liverworts, and ferns all require water for reproduction
- gymmnosperms and angiosperms:
a) do not need water for reproduction
b) evolved to have small portable male gametophyte that is encased in sporopollenin
c) reproduces through pollen
2 Structures that contains sporangia
- sorus (clusters of sporangia)
- strobilus (cluster of leaves with a sporangium at its base)
Pollen
Small portable male gametophyte encased in sporopollenin
Lignin
- provides structure and support to cell walls
When was the first evidence of plants found? What was it?
- 476 million years ago
- sporopollenin
- imprint of waxy cuticles
Mitochondria
- found in all cells
- double membrane bound organelle that transforms energy into a universally usable form
What organisms contain chloroplasts?
- found in eukaryotic photoautotrophs
Central Vacuole
- takes up most of space in plant cel
- stores water, salts, and sugar
- provides skeletal support
- creates turgor pressure used for movement
Primary Cell Wall
- made of cellulose
- thin and flexible
Secondary Cell Wall
- contains lignin
- thick and rigid
Plant Tissue
- a group of similar cells that work together to perform a specific function within a plant
- 4 Types
1. Meristematic
2. Dermal
3. Ground
4. Vascular
Meristematic Tissue
- clusters of totipotent cells capable of making all the other tissues
- where growth/cell division occurs
- divides through mitosis: produces one meristematic cell and one differentiated cell
Totipotent
“total potential”
- having the ability to differentiate into all cell types
Dermal Tissue
- covers the body
- 3 types
1. epidermal cells
2. guard cells
3. trichomes
Epidermal cells
- living cells
- thin primary cell wall
- no secondary cell wall
- non photosynthetic
- covers all photosynthetic tissues
- large
- secretes waxy cuticles
Guard cells
- photosynthetic
- sausage shaped
- comes in pairs
- elastic primary cell walls
- stoma is between two guard cells
- opens and closes the stoma
Trichomes
- living or dead cells that grow on the epidermis
- functions:
a) clinging
b) defense (physical and chemical)
c) traps moisture and blocks wind/reduces dessication
Ground Tissue
- storage
- support
- most photosynthesis
3 types
1. parenchyma
2. collenchyma
3. sclerenchyma
Parenchyma
- composed of large amounts of amorphous living cells
- loosely packed
- thin primary cell wall (allows for easy transport)
- stores energy in form of glucose and starch
- abundant in roots
- photosynthetic tissue
- mesophyll
- can de-differentiate (become meristematic)
Mesophyll
- inside of the leaf
- between the epidermal layers of a leaf
Collenchyma
- long columnar cells
- living cells
- thick primary cell wall (more rigid)
- underneath epidermis of young stems
- flexible structural support
- ex: celery
Sclerenchyma
- dead hollow cells full of lignin
- thick secondary cell wall
- structural support
- 2 Types
1. Fiber
2. Sclereids
Fiber
- long
- thin
- comes in bundles
- structural support
- plant version of bones
- not digestible
Sclereids
- amorphous
- ex: shells of nuts, bark, unripe fleshy fruit
- not digestible
- mechanical support and protection
Vascular Tissue
- used for transport of water, nutrients, and sugars
- 2 types
1. xylem
2. phloem
Xylem
- unidirectional transport of H2O and nutrients (from the ground up)
- 2 Types
1. Tracheids
2. Vessels
Tracheids
- narrow/long, dead hollow cells
- lignified secondary cell wall
- connected by pits
- transports water and nutrients
- provides structural support
- found in all vascular plants
Pits
- area where there is no secondary cell wall
- primary cell was is vert permeable so nutrients and water can flow through
- vertical and lateral
Vascular plants
- ferns
- gymmnosperms
- angiosperms
Vessels
- shorter, stouter, dead hollow cells
- connected by pores
- horizontal pits
- transports water and nutrients
- provides structural support
- more efficient than tracheids
- limited to angiosperm
Phloem
- bidirectional transport of sugars and hormones
- 2 types
1. sieve-type members
2. companion cells
Sieve-type members (STMs)
- short barrel like living cells
- non-nucleated
- connected through a sieve plate
- cytoplasm is continuous through connected cells
- cannot make proteins due to lack of chromosomes
Companion cells
- paired with STMs
- living nucleated cells that support the STMs
Where does growth occur?
behind
2 types of growth
Primary and secondary
Primary Growth
- length
- occurs in all plants
Secondary growth
- girth
- occurs in woody plants
- addition or lengthening of cells
- results from 2 lateral meristems from de-differentiation of parenchyma
- 2 types
1. cork cambium
2. vascular cambium
Primary growth at Apical Meristem
- cell division at AM produces 3 primary meristems that are partially differentiated
1. protoderm
2. ground meristem
3. procambium
Partially differentiated primary meristems
can only reproduce a specific cell
Protoderm
produces dermal tissue
Ground meristem
produces ground tissue
Procambium
produces vascular tissue
What indicates the type of primary meristem that is produced?
hormones
Cortex
- parenchymal tissue underneath epidermal tissue
Vascular bundle
plant tissue that contains both xylem and phloem
Pith
- occupies the center of stem and root cells
- stores and transports nutrients
How are branches and leaves formed?
Occurs when parenchymal cells de-differentiate
Root Cap
- secretes mucus and lubricates soil
How does the root system of plants have a symbiotic relationship with fungi?
- the root cap secretes mucus that promotes fungi growth
- fungi decomposes organic matter that creates nutrients for the plant
Columella cells
- detects gravity and growth
Root Hairs
- horizontal growth of root epidermal cells
- increases the absorptive surface area of the roots
Where are xylem and phloem found relative to the cell?
xylem is found towards the inside of the cell and phloem is found towards the outside
Cork Cambium
- comes from de-differentiation of cortex
- continuous ring
- produces cork cells to outside
Cork cells
- full of suberin (wax)
- creates a barrier between epidermal layer and kills the epidermal layer due to water and nutrient loss
Vascular Cambium
- forms a discontinuous ring between primary xylem and primary phloem (within the vascular bundle)
- produces secondary xylem on the inside and secondary phloem on the outside
Why does more xylem accumulate than phloem in secondary growth?
- secondary xylem produce more frequently
- phloem is living, so those cells die and break down as they’re being produced
What is bark composed of?
the outer four layers
- cork
-cork cambium
- secondary phloem
- vascular cambium
What is wood composed of?
- secondary xylem
- parenchymal rays
- fibers
Spring and early summer secondary growth
- fairly warm and wet
- vascular cambium produces larger xylem (in diamater) and more vessels (in angiosperms)
- lighter in color
- known as spring wood
Late summer secondary growth
- dry and hot
- produce smaller xylem (in diameter) and fewer vessels (in angiosperms)
Angiosperms
- flowering plants (produces flowers or fruits)
- contains vessels
Gymmnosperms
- contain naked seeds and use cones for protection
- does not contain vessels
Parenchymal rays
- transports water and nutrients stored in the secondary xylem
What are the three plant organs?
- roots
- stems
- leaves
Roots
- 3 functions:
1. stores water and energy
2. anchorage
3. water and nutrient absorption
Secondary growth in roots
- outer pericycle becomes cork cambium and produces cork
- endodermis, cortex, and epidermis die due to lack of energy from phloem
- makes bark
- inner pericycle becomes vascular cambium
Pericycle
- parenchyma cells that lie just beneath the endodermis
- required for secondary root growth
Endodermis
- one cell layer thick sleeve that surrounds vascular tissue
- composed of parenchyma cells
- contains casparian strip
- function is selective uptake of water and nutrients
Casparian strip
- composed of suberin
- forces water and nutrients to go through the cytoplasm of the endodermal cells
2 Major Types of Root Systems
- Tap root system
- Fibrous root system
Tap Root System
- one large main root and few branch roots
- used in plants that store energy underground
- large mesophytes
- xerophytes
Mesophyte
plant that needs a moderate amount of water
Xerophyte
plant that needs little water
Fibrous Root System
- lateral roots close to surface of ground because water and nutrients are closer to the surface
- no main root, but many roots/branch roots
- hydrophytes
- small mesophytes
Aerial Root
- in tropical epiphytes
- grow above the ground to help anchor the plant
- ex: orchids
Pneumatophore Roots
- vertical extensions from below ground roots
- function is to get oxygen
- hydrophytes
Parasitic Roots
- parasitic epiphytes
- roots penetrate into the vascular tissue of host for water, nutrients, and energy
Hydrophyte
plant that needs a lot of water
Epiphyte
plant that grows on the surface of other plants
Energy Storage Roots
- sugar beets, sweet potatoes
- store energy
Water storage roots
store water
Buttress roots
- roots above the ground that trap organic matter and is the source of nutrients for the plant
- provides stability
- tropical trees
Lenticel
- area of unsuberized cork
- function is oxygen uptake
Heartwood
- non-functional wood (secondary xylem, parenchymal rays, fibers)
- resin filled xylem
- parenchyma cells are dead
Sapwood
- functional xylem and parenchymal tissue
Thorn stems
- used for protection
Bulb stems
- knob-like below ground stems
- energy storage
- garlic
Rhizome stems
- below ground lateral stems that produce above ground leaves
Runner stems
- above ground lateral stems that produce plants
Tuber stems
- below ground energy storage
- potatoes
Tendril stems
- climbing stems
Cladophyll stems
- branch leaves
- flat, photosynthetic water storing stems
- xerophytes
Palisade mesophyll
- columnar parenchyma cells in the middle of the leaf
- allows for transport and movement within the leaf
What are the veins on a leaf composed of?
Vascular tissue
Bundle Sheath
- surrounds the vascular tissue
- regulates movement within the leaf
Spongy mesophyll
- facilitates gas exchange
Stomata pit
- pit made in the lower surface of the leaf
- stoma is embedded in the pit and surrounded by trichomes to prevent water loss
Bract leaf
- flower petal like leaves
- ex: poinsettia
Spine leaves
- used for protection
Window leaves
- below ground leaf where only a small portion extends above ground
- small portion is transparent and allows the plant to photosynthesize
Water storage leaves
- ex: aloe
- chemically protects itself
Energy storage leaves
- ex: onions
- typically below ground
Insectivorous leaves
- attracts insects with a sugary fluid then released digestive enzymes to break down the insect
- in nitrogen limited areas
