DAT Diversity of Life Cont Flashcards
Evolution Order
Jawless fish, bony fish, amphibians, reptiles, birds, mammals
how to remember evolution order
James Bond: A Real Barbaric Man
what does seed include
young dormant sporophyte, storage of nutritive tissue, and an outer protective coat
what kind of cellular division is observed in plants
alteration of generation (diploid and haploid)
vegetative propagation
form of asexual reproduction in plants leading to genetically identical offspring
seeded plants include…
gymnosperms, angiosperms
2 groups of angiosperms
dicots and monocots
evolution order of plants
bryophytes then gymnosperms then angiosperms
Cotyledons
storage tissue that provides nutrition to developing seedlings
leaf venation
pattern of veins in leaves
flower parts
number of petals sepals stamens and other parts
Cotyledons in dicots
2 cotyledons
leaf venation in dicots
netted branching pattern
leaf venation in monocots
parallel
vascular bundles in dicots
organized in circle
vascular bundles in monocots
scattered
ground tissues in plants
provide structural support (parenchyma, collenchyma, sclerenchyma)
Parenchyma
this is the most
common ground tissue. They have thin cell walls. Their function is storage, photosynthesis, and secretion
Collenchyma
they have thick but flexible cell walls, and serve mechanical support functions
Sclerenchyma
they have thicker walls than collenchyma, and also provide mechanical support.
Dermal tissue
this tissue includes epidermis cells that cover the outside of plant parts. Guard cells are a type of epidermal cells that surround stomata, hair cells, stinging cells, and glandular cells
vascular tissue
consists of xylem and phloem
kinds of xylem cells
tracheids and vessel elements
xylem
this tissue conducts water
and minerals and also has functions in mechanical support. The xylem has a second cell wall for additional strength.
tracheids
long and tapered where water passes laterally from one to another through pits
Vessel elements
these structures are shorter and wider, and they have less or no taper at the ends. A column of vessel elements (members) is called a vessel.
Phloem
this tissue transports sugar. It is made of cells called sieve-tube members (elements) that form fluid conducting columns called sieve tubes
parts of the embryo
Epicotyl, plumule, hypocotyl, radicles, coleoptiles
Epicotyl
this part is at the top portion of the embryo and becomes the shoot tip
Plumule
these are young leaves often attached to the epicotyl and located underneath the epicotyl.
Hypocotyl
located at the bottom region of the young shoot. attached to cotyledons
Radicles
adicles develop from below the hypocotyls and become the roots
Coleoptiles
sheath in monocots that surrounds and protects the epicotyl.
what causes seed to break dormancy pd
specific environmental cues such as water, temperature, light, or seed coat damage
germination begins with..
imbibition of water, then enzymes are activated, respiration begins
growth of young seedlings/plants occurs at…
tips of roots and shoots
root growth consists of several sections, what are they
root cap, zone of cell division, zone of elongation, zone of maturation
root cap
it protects the
apical meristem behind it. The root cap secretes polysaccharides that moisten the soil, permitting root growth
Zone of cell division
formed from the dividing cells of the apical meristem. This zone is right above the apical meristem
Zone of elongation -
newly formed cells from the zone of cell division absorb water and elongate. This zone is responsible for our perception of growth
Zone of maturation
cells differentiate and mature into the xylem, phloem, parenchyma, or epidermal cells (root hairs may grow here)
secondary grwoth
increases girth, origin of woody plant tissues
structure of root from outside to in
epidermis, cortex, endodermis, vascular cylinder
epidermis of root
lines the outside surface of the root. In the zone of maturation, the epidermal cells produce root hairs. When the zone of maturation ages, the root hairs die.
Cortex
makes up the bulk of the root.
Endodermis
this is a ring of tightly packed cells at the inner-most portion of the cortex.
Vascular cylinder (stele)
made up of vascular tissue (phloem and xylem) and the pericycle. The stele is located within the endodermis.
primary structure of stems
epidermis, cortex, vascular cylinder
vascular cambium (secondary structure)
located between the primary xylem (located closer to the center) and the primary phloem (located closer to the outside). The vascular cambium is a cylinder of tissue that extends the width of the stem and the root.
Wood is formed from…
mature (dead) xylem tissues
structure of leaf
Epidermis, Palisade mesophyll , Spongy mesophyll, Guard cells, Vascular bundles
func of epidermis leaf
protective layer(s) that is covered with a cuticle which reduces transpiration
fucn of palisade mesophyll
specialized for photosynthesis
Spongy mesophyll func
Numerous intercellular spaces provide air chambers for carbon dioxide to reach photosynthesizing cells, and for oxygen to reach respiring cells
Guard cells func
control the opening and closing of stomata. Therefore, guard cells also control gas exchange
Vascular bundles
mostly transport
2 pathways for water to move thru roots
apoplastic pathway, symplastic pathway
apoplastic pathway
water moves through cell walls and intercellular spaces from one cell to another without ever entering the cells
symplastic pathway
water moves through the cytoplasm of one cell to another through plasmodesmata (small tubes that connect cytoplasm of adjacent cells)
osmosis
water moves from the soil through the root and into the xylem by a concentration gradient.
Capillary action
capillary action causes the rise of liquids in narrow tubes, and it can also contribute to the movement of water up the xylem.
Cohesion-tension theory
transpiration, cohesion, bulk flow
factors involved in the mechanism of open and close stomata (gas exchange)
high temp (close) low CO2 (open) night or day,
guard cells have what kind of receptor
blue light, when stimulated the stomata opens
translocation
movement of carbohydrates thru phloem from a source (leaves) to sink (site of carb util)
pressure-flow hypothesis
Sugars enter the sieve-tube members, Water enters sieve-tube members, Through sieve tubes, pressure in the sieve-tube members at the source moves water and sugars to sieve-tube members at the sink, Pressure is reduced in sieve-tube members at the sink as sugar is removed for utilization by nearby cells
Auxin (IAA-indoleacetic acid)
promotes plant growth and the elongation of cells by increasing the proton concentration in primary cell walls
Gibberellins (GA)
group of hormones that promotes cell growth (flower and stem elongation). Gibberellins are synthesized in young leaves/roots/seeds and then transported to other parts of the plant.
Cytokinins
stimulates cytokinesis, and it also stimulates and influences the direction of organogenesis. Cytokinins stimulate the growth of lateral buds, which weakens the apical dominance created by auxins.
Ethylene (H2C=CH2)
gas that promotes the ripening of fruit, the production of flowers, and influences leaf abscission and apoptosis.
Abscisic acid (ABA)
growth inhibitor. In buds, it delays growth and forms scales, and maintains dormancy in seeds
Phototropism
when a plant grows towards or away from a light source.
Gravitropism (geotropism)
plant’s response to gravity by the stems and roots. Auxin and gibberellins are involved. If the stem is horizontal, auxin concentrates on the lower side and the stem bends upward. If the root is horizontal, auxin produced at the apical meristem moves up in the roots and concentrates on the lower side.
Thigmotropism
this is a plant’s response to touch. For example, thigmotropism can be seen when vines wrap around an object that they are in contact with
Photoperiodism
response in plants to changes in photoperiod
Long-day plants
these plants flower in the spring and early summer when daylight is increasing
Short-day plants
these plants flower in late summer and early fall when daylight is decreasing
Day-neutral plants
these plants do not flower in response to daylight changes but due to temperature or water instead
Phytochromes
proteins modified with light-absorbing chromophores. (red and far red)
