Bio 2 Exam 2 Tuesday Notes

how are plants described as roots (essay)

main root (taproot), then secondary roots (lateral roots), these arise from vascular cambium. root hair is a projection of a dermal cell, that absorbs minerals. There are aerial/prop roots that grow above ground

tissue types role for photosynthesis

dermal tissue have protective epidermal cuticle and guard cells and stomata that lets an exchange of photosynthetic gasses throughout the cell. ground tissue have parenchyma mesophyll that contain tightly packed chloroplasts for efficient capturing of light. Vascular tissue have phloem that transport sugars/ photosynthetic products throughout the plant to supply all parts with necessary materials and nutrients.

vascular cambium

main growth tissue in roots and stems of plants-widens stem

cross section: root or stem?

roots are circular, stem cells have ring-shape

summarize  how shoots grow longer, fatter and branch

they grow at the tips, branch from vascular cambium, as it gains more minerals, half of new cells extend root, other half are pushed forward into soil. grow in growth at secondary meristem

stem

shoot, support plant, conduct minerals and nutrients to plant

apical bud

tip of the shoot, produces plant hormones auxin to grow axillary bud

axillary bud

allow branching of plant

node and internode

part of stem where one or two leaves emerge, internode is the distance between two successful nodes

primary/epical meristem

often suppresses lateral meristems

meristem

tissue found at tips of roots and shoots that actively divide cells to form new tissue

cork cambium

widens epidermis so plant can keep growing during secondary growth

secondary growth

growth in girth by lateral meristems from cork and vascular cambium ex: wood growth, xylem and phloem working

simple leaves

a single leaf

compound leaves

two or more distinct leaflets

doubly compound leaves

twice divided, leaflets are on secondary vein that divided from a branch of the main branch

petiole

attaches leaf to stem

leaf blade

helps plant move and store photosynthesis products

leaf vein x/p

xylem transports water and minerals, cell products like energy are transported via phloem

primary growth

rapid growth at meristems

pinnate

one main vein

palmate

several main veins

apical dominance

inhibitory control exercised by the apical portions of the shoot over the growth of the lateral buds below

determine vs indeterminate growth

determinate: plants stop growing after flowering. indeterminate growth: plants continue growing after flowering

stamen

whorl that is male part of flower, contains filament and anther

anther

produce and spread pollen

filament

carry nutrients to anther

carpel/pistil

female part of plant, contains stigma, style, ovary, ovule

stigma

collects pollen

style

prevents incompatible pollen from entering ovary

ovary

prepare for fertilization, protect zygotes

receptacle

thickened section of flower stem where flower organs grow from

petal

whorl that attracts pollinators

sepal

outer whorl for protection

angiosperm life cycle

diploid until meiosis, micro/megasporangia produce haploid pollen, mega/micro gametophyte processes lead to fertilization. sporophyte dominant

what is double fertilization?

two sperm cells unite with two cells in female gametophyte (embryo) to form the zygote and endosperm

seed dormancy and imbibition

adaptation where they are inhibited from sprouting even though they are ready-until they get the signal that everything is okay. Imbibition- when water is given to seed, so it can germinate.

hypocotyl

portion below cotyledon

epicotyl

portion above cotyledon

cotyledon

near embryo, provides plant nutrients to grow

seed dispersal for fruits methods (2)

wind and animals

Asexual (vegetative) reproduction in plants:

Fragmentation and apomixis

sexual reproduction in plants, and term for when they cannot:

self fertilization & self incompatibility

How humans have impacted plants:

genetic engineering: resistance genes, changing molecularly. Selective breeding: GMOS, etc.

cloning and cutting, why?

cloning to produce identical plants quickly/economically, cut at base to grow more healthy leaves, make it bushier