dendro exam #2 (misc.)

what does a monoecious gymnosperm look like?

pollen and strobili on same tree

what does a dioecious tree look like?

male and female sexual organs seperated by tree

what are female cones called?

megastrobili

what are male cones called?

microstrobili

describe what a male cone does and what it looks like

it produces pollen (stored in pollen sacs), sheds pollen, then dies. it is papery and ephemeral.

describe what a female cone does and what it looks like

it stores ovules between woody ovuliferous scales and bracts

how long does it take seed cones to mature?

most mature in 1 year, pines take 2 years

what are the differences in seed storage in gymnosperms and angiosperms?

in gymnosperms, seeds are not enclosed in a fruit, and pollen lands directly on the ovule. in angiosperms, seeds are enclosed in an ovary wall and sperm travels through pollen tube to reach them.

what does a monoecious angiosperm look like?

male and female flowers on the same tree

what does is a perfect flower?

a flower with male and female parts on the same flower (ie. yellow poplars, tulips)

what is an imperfect flower?

flower that only has male or female parts on individual flowers (ie. oaks: male flowers in catkins female flowers develop into acorns)

what tree has annual gender changes and can vary from female / male / cosexual many times before death?

striped maple

what is a genetic load?

a reduction in fitness compared to a population with error free genotypes, caused by selfing or mating with close relatives

how does a monoecious tree prevent selfing?

organ placement on the tree, protandry, prorogyny, and self incompatability genes

what is a juvenile tree?

a tree that has yet to produce flowers or seeds

what is a mature tree?

a tree with the ability to produce flowers and seeds

what are the pros and cons of wind pollination?

pros: does not need a vector system to get pollen to the female

cons: requires lots of carbs and nitrogen for bulk of pollen

what are the pros and cons of animal and insect pollination?

pros: less energy and resources go towards pollen production

cons: reliant on vector to female flower, resources go towards attracting pollinators

is fertilization always needed for development?

no, some species only require pollination, and other species require no pollination at all (seedless fruits like bananas, watermelons, grapes)

what are the three types of fruit and what do they mean?

fleshy (fleshy), dry dehiscent (splits open), dry inhidiscent (doesn’t split open)

what is a simple fruit?

a single ovary becomes the fruit

what are the types of compound fruit?

aggregate fruit (fused ovaries of one flower)

multiple fruit (fused ovaries of multiple flowers)

what are five mechanisms of seed dispersal?

animals, water, wind, gravity, and ejection

what are some requirements for germination?

moisture, temperature, light, gas exchange, and substrate

what is physiological (internal) dormancy?

chemical inhibitor prevents germination

what is physical (morphological) dormancy?

impermable seed coat too hard for embryo to break out of

what are methods to breaking dormancy?

stratification (moisture and temperature treatment)

scarification (beat that thang up)

what are five methods of asexual reproduction?

cloning, coppicing (stump sprouting), root suckering, detached branches, and layering

what is a meristem?

the location of cell division and plant growth

what do the primary meristems make?

elongating shoots and vertical growth

what are the three primary peristems and what do they make?

protoderm makes the epidermis; procambium makes primary xylem, primary phloem, and vascular cambium; ground meristem makes cortex and pith

what are the two secondary meristems and what do they make?

vascular cambium makes secondary xylem (wood) and secondary phloem (inner bark), phellogen makes phellem (cork) and phelloderm

what is a fiber?

a type of wood cell that provides strength

what is a tracheid and how does water move through it?

a smaller and thinner water conducting cell that is closed at the end, water moves through pit pairs made of torus (middle) and margo (margin) in gymnosperms or homogenous in angiosperms

what is a vessel and how does water move through them?

a wider and longer water conducting cell that is open at the end and stacks to form tubes

do conifers and hardwoods have both tracheids and vessels?

conifers only have tracheids. hardwoods have both.

what is a ray?

a radial file of cells in the secondary xylem made of living and dead cells

what does springwood xylem look like?

thin cell walls and big lumens

what does summerwood xylem look like?

thicker cell walls and smaller lumens

what does diffuse porous mean?

large vessels throuhgout annual ring, multiple rings of the secondary xylem are functional

what does ring porous mean?

a bulk of vessels are in the springwood, only most recent rings of secondary xylem are functional

what is girdling?

removing the periderm and phloem from a tree, restricting sugar transport and damaging the vascular cambium

what is phloem and what is it made of?

phloem moves sugar from leave to be stored in stem or roots and is made of sieve elements and companion cells

what did american chestnut provide?

rot resistant, straight grained timber; wood that burned with no smoke; edible crop that had natural and human value; use in every day furniture (cradle to grave)

what is chestnut blight and what does it do to the tree?

a fungus introduced from asian chestnut trees, fungus wedges under bark and excretes oxalic acid that kills tree tissue, which girdles tree