Botany Exam 3

Herbs

only the primary plant body develops from the apical meristem

woody species

secondary tissues are produced in the stem and root

the two tissues that compose woody species

primary and secondary tissue

primary growth

lengthening of tips and roots/shoots (apical meristem)

advantages and disadvantages of primary growth

advantages: produce a lot of seeds

disadvantages: vulnerable to herbivores

secondary growth

widening of stems and roots driven by vascular and cork cambium

advantages and disadvantages to secondary growth

advantages: structural support and facilitating long-distance transport

disadvantages: greater need for defenses and less energy used for reproduction

vascular cambium

one of the meristems that produced the secondary plant body

fusiform initals

long, tapered cells that divide to elongate xylem and phloem cells in the vascular cambium

ray initals

short and cuboidal, form xylem and phloem cells that function in storage or albuminous cells

hardwoods

contain many fibers (oak,hickory, walnut)

softwoods

contain few fibers (pine,fir,spruce)

Growth rings

appear due to different growth of early wood (spring) and late wood (summer)

Early wood

higher amount of wide vessels or tracheids (more water)

Late wood

fewer vessels and narrower thick-walled tracheids

growth during WINTER

no growth during winter because plants are dormant

heartwood

center of a log that is darker, dryer and more fragrant

tyloses

found it heartwood- sealed off with protoplasm to prevent disease

phenolic compounds

released by parenchyma cells to inhibit the growth of bacteria and fungi

sapwood

outer wood

Anatomy of a Tree-Bark

Layers of periderm, secondary phloem

Anatomy of a Tree- Secondary Xylem

heartwood, sapwood

Anatomy of a Tree- Outer Layer

vascular ray and growth ring

Asexual plant reproduction

offspring with identical copies of parent genes

advantages to asexual reproduction

rapid colonization of a new site and isolated individuals can reproduce

disadvantages to asexual reproduction

all may be adversely affected by minor changes to climate

sexual plant reproduction

progeny are genetically diverse

advantages of sexual plant reproduction

some offspring can colonize new sites with characteristics not suitable for parents

disadvantages of sexual plant reproduction

isolated individuals cannot reproduce

structured involved in sexual reproduction

stamens and pistils (female, containing ovaries and ovules)

complete flowers

has all 4 floral appendages (sepal, stamen, and carpel)

incomplete flowers

lack at leas one appendage

cross pollination

transfer of pollen from the anther of a flower to the stigma of another of the same species

self-pollination

transfer of pollen from the anther (male part) to the stigma (female part) of the same plant

wind pollination

natural process where pollen is dispersed by wind rather than animals or other vessels

animal pollination

when animals transfer pollen from one flower to another

how plants prevent self pollination

anthers and stigma mature at different times and flowers do not open simultaneously

exocarp

the outer layer-skin or peel

mesocarp

middle layer/flesh

endocarp

innermost layer- is wither tough or quite thin

pericap

entire fruit wall

monoecious

staminate flowers are located on the same plant as carpellate flowers (both male and female reproductive organs)

dioecious

individual plants that produce only staminate flowers while others produce only carpellate flowers

actinomorphic features

radically symmetrical

zygomorphic flowers

flowers that have co-evolved with animals

Hypogynous flower

ovary is below

Perigynous flower

ovary is in between

Epigynous flower

Ovary is on top

dry fruits

inedible to animals

fleshy fruits

eaten to disperse seed

short distance transport

trasnsfer of basic nutrients from cell to cell

Long distance transport

via xylem and phloem, between cells that are not close neighbors

Passive Transport

solutes move in response from high concentration to low

Active Transport

movement against the concentration gradient (low to high)

Osmosis

diffusion through a selectively permeable membrane

selectively permeable membrane

allows for certain substances to pass through

aquaporins

protein channels that allow for water molecules to pass through more rapidly

factors that affect diffusion

temperature,concentration gradient, electrical charge, distance

Isolation mechanisms

inhibit the movement of different substances

Isolation mechanisms examples

diffusion outward is stopped by the cuticle of the epidermis

Pressure potential

effect pressure has on water potential (directly proportional)

Osmotic potential

effect solutes have on water potential (always negative)

matric potential

adhesion to structures such as cell walls, membranes, and soil particles (always negative)

incipient plasmolysis

when the protoplast has lost enough water to pull slightly away from the wall, cell is plasmolyzed

motor cells

“joints” located at midrib or petiole attachment that allow leaves to move in response to various stimuli

transfer cells

inner surface of the wall that has numerous finger-like and ridge like outgrowths- high volume of transport occurs