AP Exam Reivew

2006-2007

Plants

AP Biology

Plant Anatomy Roots anchor plant in soil, absorb

minerals & water, & store food fibrous roots

Monocots (grass) tap roots

Dicots (beans, carrots) root hairs

increase absorptive surface area

AP Biology

Plant Anatomy Leaves

mesophyll tissue veins (vascular bundles)

Shoots (stem)

nodesinternodes

Terminal/apical buds

Axillary buds

AP Biology

Plant CELL types in plant tissues Parenchyma

“typical” plant cells = least specialized

photosynthetic cells, storage cells tissue of leaves, stem, fruit, storage

roots

Collenchyma help support without restraining

growth remain alive in maturity

Sclerenchyma very thick, “woody” secondary walls support rigid cells that can’t elongate dead at functional maturity

AP Biology

Vascular Tissue Xylem

move water & minerals up from roots dead cells at functional maturity

only cell walls remain need empty pipes to efficiently move H2O transpirational pull

Phloem Living cells at functional maturity cell membrane, cytoplasm

control of diffusion lose their nucleus, ribosomes & vacuole

more room for specialized transport of liquid food (sucrose)

AP Biology

Phloem: food-conducting cells carry sugars & nutrients throughout plant

sieve tube

companion cell

living cells

plasmodesmata sieve plate

AP Biology

Transport in plants H2O & minerals

transport in xylem transpiration

evaporation, adhesion & cohesion negative pressure

Sugars transport in phloem

Calvin cycle in leaves loads sucrose into phloem

positive pressure

Gas exchange photosynthesis

CO2 in; O2 out stomates

respiration O2 in; CO2 out

AP Biology

Water flow through root Porous cell wall

water can flow through cell wall route & not enter cells plant needs to force water into cells

Endodermis Contains Casparian Strip – selectively permeable membrane Minerals that enter root must pass through to get to xylem Prevents olutes in xylem from leaking out

AP Biology

Mycorrhizae increase absorption Symbiotic relationship

between fungi & plant symbiotic fungi greatly

increases surface area for absorption of water & minerals

increases volume of soil reached by plant

increases transport to host plant

AP Biology

Growth in Plants Specific regions of growth: meristems

stem cells: perpetually embryonic tissue regenerate new cells

apical shoot meristem growth in length primary growth

apical root meristem growth in length primary growth

lateral meristem growth in girth secondary growth

AP Biology

Plant HormonesName Effect

Auxin 1. Controls cell division & differentiation2. Phototropism (asymmetrical distribution of auxin)3. Apical dominance

Gibberelins 1. Stem elongation2. Fruit growth3. Seed germination

Abscisic acid 1. Slows growth2. Seed dormancy

Ethylene 1. Fruit Ripening2. Autumn leaf drop

(apoptosis)

Water Potential✦ Predicts movement of

water into/out of plant cells.

✦ Water moves from area of high --> low water potential

✦ To increase water potential

✦ Increase pressure

✦ Decrease solute

We can calculate solute potential

✦ i = ionization constant

✦ C = molar concentration

✦ R = pressure constant = 0.0831

✦ T = temp. in Kelvin (Celsius + 273)

AP Biology

Hormones and Endocrine System Animals rely on 2 systems

for regulationendocrine system

system of ductless glands secrete chemical signals

directly into bloodchemical travels to target

tissuetarget cells have receptor

proteinsslow, long-lasting response

AP Biology

Nervous & Endocrine systems linked Hypothalamus = “master nerve control

center” nervous system receives information from nerves around body

about internal conditions releasing hormones: regulates release of

hormones from pituitary

Pituitary gland = “master gland” endocrine system secretes broad range

of “tropic” hormones

hypothalamus

pituitary

posterior

anterior

AP Biology

Thyroid gland

hypothalamus

anteriorpituitary

gonadotropic hormones:follicle-stimulatinghormone (FSH) & luteinizing hormone (LH)

Mammaryglandsin mammals

Musclesof uterus

Kidneytubules

posteriorpituitary

thyroid-stimulating hormone(TSH)

antidiuretic hormone(ADH)

Adrenalcortex

Testes Ovaries

adrenocorticotropic

hormone (ACTH)m

elanocyte-stimulating horm

one(MSH)

oxytocin

prolactin (PRL)

grow

th h

orm

one

(GH)

tropic hormones = target endocrine glands

Boneand muscle

Liver

AP Biology

liver

pancreas

liver

Regulation of Blood Sugar

blood sugar level(90mg/100ml)

insulin

body cells takeup sugar

from blood

liver storesglycogen

reducesappetite

glucagon

pancreas

liver releasesglucose

triggershunger

high

low

FeedbackEndocrine System Control

islets of Langerhans beta islet cells

islets of Langerhansalpha islet cells

AP Biology

Regulating metabolism Hypothalamus

TRH = TSH-releasing hormone

Anterior Pituitary TSH = thyroid stimulating hormone

Thyroid produces thyroxine hormones metabolism & development

bone growth mental development metabolic use of energy blood pressure & heart rate muscle tone digestion reproduction

AP Biology

Regulation of Blood Calcium

blood calcium level(10 mg/100mL)

calcitonin

parathyroid hormone (PTH)

↑ Ca++ uptakein intestines

high

low

FeedbackEndocrine System Control

↑ kidney reabsorption

of Ca++

bones release Ca++

↓ kidney reabsorption

of Ca++

Ca++ depositedin bones

activated Vitamin D

thyroid

parathyroid

AP Biology

Endocrine System ControlBlood Osmolarity

blood osmolarity highOr blood pressureBelow set point

osmoreceptors inhypothalamus

post. pituitary

ADH

increasedwater

reabsorption

increasethirstnephron

nephron(JGA)

JuxtaGlomerularApparatus

renin

angiotensinogen

angiotensin

aldosterone

adrenalgland