Biology G11 Final Exams

A1.1-B3.1 / personalized

3.2 coronary arteries

arteries branching out from the aorta that supply oxygenated blood to the heart tissue

3.2 Cortex function [ stem ]

 storage/structural support/photosynthesis (layer under epidermis)

3.2 endodermic [ root ]

inner skin of cells that water passes through to access the xylem

3.2 cortex [ root ]

unspecialized cells ‘bulk out’ root → strength/higher surface area

3.2 epidermis [ root ]

absorbs water/minerals from soil using root hairs (long, narrow outgrowths)

3.2 journey of blood, o2, co2 in fish

heart → gills → body → heart

• oxygen diffuses from water → gills → blood

• CO2 diffuses from blood → gills → water

3.2 lub dub mechanism

• lub = AV valves close, seminular valves openn (ventricular systole)

• dub = Semilunar valves close, AV valves remain closed (ventricular diastole)

a1.1 specific Heat Capacity

energy required to raise the temperature of 1g by 1C

a1.1 surface tension

strong cohesive forces between water molecules, resisting external forces 

a1.1 goldilocks zone (2)

• habitable zone with a temperature allowing water to exist near a star

• Conditions: liquid water, gravitational pull, atmosphere to shield surface from ionizing radiation

a1.2 nucleotides linkage (sugar-phosphate backbone)

covalent/phosphodiester bonds (thru condensation reaction → (lose OH group in phosphate plus H in sugar = H2O)

a1.2 purines and pyrimides (2)

• purines (double-ringed): AT

• pyrimidines (single-ringed): CG

a1.2 no. of H-bonds in ATGC

• A-T: 2

• G-C: 3

a1.2 H1 histone function

The H1 histone stabilizes the nucleosome, condenses the DNA

a1.2 Chargaff’s Experiment (2)

• theory: DNA consists of repeating sequences of 4 nucleotides (i.e. equal amounts), did not vary

• Conclusion: genetic sequences vary between organisms, DNA is not a tetranucleotide; ratio between A-T and C-G are similar

a2.1 miller urey vs early earth (2)

• miller (HIGH) vs early (LOW): methane, ammonia

• miller (LOW) vs early (HIGH): CO2, O2, N2

a2.2 electron microscope

beams of electrons form fluorescent screen (kills specimen) 

a2.2 Fluorescence stains

when a substance absorbs light and emits it as a longer wavelength

a2.2 Immunofluorescence stains

Fluorescent stains are marked on antibodies, which interact with antigens on the cell

a2.2 freeze-fractured electron microscopy

cell frozen, fractured, etched, replicated → viewed thru microscope

a2.2 Cryogenic Electron Microscopy (cryo-EM)

A grid of frozen protein solution is placed under an electron microscope and bombarded with electron beams